Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Toshiro Matsui Last modified date:2019.05.17

Professor / Food Science and Biotechnology / Department of Bioscience and Biotechnology / Faculty of Agriculture


Papers
1. Anti-diabetic Effect of Acetic Acid-Free Red Vinegar in Spontaneously Diabetic Torii Rats.
2. Tatsuro Yamamoto, Chiyomi Sakamoto, Hiroaki Tachiwana, Mitsuru Kumabe, Toshiro Matsui, Tadatoshi Yamashita, Masatoshi Shinagawa, Koji Ochiai, Noriko Saitoh, Mitsuyoshi Nakao, Endocrine therapy-resistant breast cancer model cells are inhibited by soybean glyceollin I through Eleanor non-coding RNA, Scientific reports, 10.1038/s41598-018-33227-y, 8, 15202, 2018.10, Long-term estrogen deprivation (LTED) of an estrogen receptor (ER) α-positive breast cancer cell line recapitulates cancer cells that have acquired estrogen-independent cell proliferation and endocrine therapy resistance. Previously, we have shown that a cluster of non-coding RNAs, Eleanors (ESR1 locus enhancing and activating non-coding RNAs) formed RNA cloud and upregulated the ESR1 gene in the nuclei of LTED cells. Eleanors were inhibited by resveratrol through ER. Here we prepared another polyphenol, glyceollin I from stressed soybeans, and identified it as a major inhibitor of the Eleanor RNA cloud and ESR1 mRNA transcription. The inhibition was independent of ER, unlike one by resveratrol. This was consistent with a distinct tertiary structure of glyceollin I for ER binding. Glyceollin I preferentially inhibited the growth of LTED cells and induced apoptosis. Our results suggest that glyceollin I has a novel role in LTED cell inhibition through Eleanors. In other words, LTED cells or endocrine therapy-resistant breast cancer cells may be ready for apoptosis, which can be triggered with polyphenols both in ER-dependent and ER-independent manners..
3. Ayano Shimizu, Takakazu Mitani, Sachi Tanaka, Hiroshi Fujii, Motohiro Maebuchi, Yusuke Amiya, Mitsuru Tanaka, Toshiro Matsui, Soichiro Nakamura, Shigeru Katayama, Soybean-Derived Glycine-Arginine Dipeptide Administration Promotes Neurotrophic Factor Expression in the Mouse Brain, Journal of Agricultural and Food Chemistry, 10.1021/acs.jafc.8b01581, 66, 30, 7935-7941, 2018.08, Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, plays an important role in cognitive abilities, including memory and learning. We demonstrated that soybean protein hydrolysate (SPH) diet suppresses age-related cognitive decline via the upregulation of BDNF in a mouse model of senescence. Our purpose was to identify novel bioactive peptides in SPH, which enhance BDNF expression. We treated mouse primary astrocytes with SPH as well as with its positively charged chromatographic fraction. Significant increases in the expression of BDNF were observed in the treatment with positively charged fraction of SPH. Among the synthesized peptides, the dipeptide glycine-arginine (GR) increased BDNF expression in vitro, and LC-TOF-MS analysis showed the presence of GR in the SPH. Furthermore, its administration in vivo increased the expression of BDNF in the cerebral cortex and the number of neurons in hippocampus and cerebral cortex. These data indicate that GR might promote neurogenesis by upregulating BDNF levels..
4. Hsuan Chung, Akihiro Shimura, Toshiro Matsui, Discriminant and simultaneous HPLC analysis of reducing and nonreducing monosaccharides on a polyethyleneimine-attached hydrophilic interaction liquid chromatography column, Food Science and Technology Research, 10.3136/fstr.24.501, 24, 3, 501-508, 2018.06, The aim of this study was to develop an analytical method for the discrimination of reducing and non-reducing monosaccharides including rare sugars on a prototype hydrophilic interaction liquid chromatography (HILIC) column. The HILIC column was composed of a glycidyl methacrylate-ethylene glycol dimethacrylate copolymer attached to 8 wt% polyethyleneimine. Seven monosaccharides (reducing aldoses: D-xylose, D-allose, and D-glucose; non-reducing ketoses: D-fructose, D-psicose, D-sorbose, and D-tagatose) were targeted. In individual HPLC analysis of both aldoses and ketoses, elution with 90 v/v% acetonitrile permitted successful detection and separation only for the non-reducing ketoses. Besides, elution of a mixture of ketoses and aldoses with 85 v/v% acetonitrile containing 5 mmol/L sodium 1-octanesulfonate (OS) (pH 4.8) enabled the simultaneous separation of all seven monosaccharides within 40 min. The polyethyleneimine-attached HILIC column allowed discriminant HPLC analysis for non-reducing ketoses using elution with 90 v/v% acetonitrile, whereas elution with 85 v/v% acetonitrile containing 5 mmol/L OS simultaneously detected both ketoses and aldoses..
5. Ryoko Yamamoto, Hisanori Minami, Hiromi Matsusaki, Mami Sakashita, Naoki Morita, Osamu Nishimiya, Naonobu Tsutsumi, Masashi Hosokawa, Yutaka Itabashi, Toshiro Matsui, Kazuhiro Ura, Consumption of the edible sea urchin Mesocentrotus nudus attenuates body weight gain and hepatic lipid accumulation in mice, Journal of Functional Foods, 10.1016/j.jff.2018.04.063, 47, 40-47, 2018.04, The beneficial health effects of edible sea urchin consumption in mice fed a normal (ND) or high-fat diet (HFD) were investigated in this study. Notably, sea urchin-administered (250, 500, 1000 mg/kg) mice exhibited lower body, liver, and visceral fat weights, lower plasma levels of aspartate aminotransferase and alanine aminotransferase, and lower hepatic triacylglycerol levels than those fed carboxymethyl cellulose (CMC). Despite the high levels of cholesterol found in sea urchins, intake of these organisms had no effect on plasma cholesterol levels among the mice tested. Additionally, sea urchin consumption resulted in enhanced levels of arachidonic acid and docosahexaenoic acid within mouse livers. Lastly, mice fed HFD with sea urchin (500 mg/kg) exhibited increased mRNA expression of uncoupling protein-1 within brown adipose tissue, compared with those fed HFD with CMC. In conclusion, consumption of sea urchin might provide a protective effect against the development of obesity and/or nonalcoholic fatty liver disease..
6. Baorui Li, Yusuke Terazono, Naoto Hirasaki, Yuki Tatemichi, Emiko Kinoshita, Akio Obata, Toshiro Matsui, Inhibition of Glucose Transport by Tomatoside A, a Tomato Seed Steroidal Saponin, through the Suppression of GLUT2 Expression in Caco-2 Cells, Journal of Agricultural and Food Chemistry, 10.1021/acs.jafc.7b06078, 66, 6, 1428-1434, 2018.02, We investigated whether tomatoside A (5α-furostane-3β,22,26-triol-3-[O-β-d-glucopyranosyl (1→2)-β-d-glucopyranosyl (1→4)-β-d-galactopyranoside] 26-O-β-d-glucopyranoside), a tomato seed saponin, may play a role in the regulation of intestinal glucose transport in human intestinal Caco-2 cells. Tomatoside A could not penetrate through Caco-2 cell monolayers, as observed in the transport experiments using liquid chromatography-mass spectrometry. The treatment of cells with 10 μM tomatoside A for 3 h resulted in a 46.0% reduction in glucose transport as compared to untreated cells. Western blotting analyses revealed that tomatoside A significantly (p < 0.05) suppressed the expression of glucose transporter 2 (GLUT2) in Caco-2 cells, while no change in the expression of sodium-dependent glucose transporter 1 was observed. In glucose transport experiments, the reduced glucose transport by tomatoside A was ameliorated by a protein kinase C (PKC) inhibitor and a multidrug resistance-associated protein 2 (MRP2) inhibitor. The tomatoside A-induced reduction in glucose transport was restored in cells treated with apical sodium-dependent bile acid transporter (ASBT) siRNA or an ASBT antagonist. These findings demonstrated for the first time that the nontransportable tomato seed steroidal saponin, tomatoside A, suppressed GLUT2 expression via PKC signaling pathway during the ASBT-influx/MRP2-efflux process in Caco-2 cells..
7. Si Jing Chen, Chiwa Aikawa, Risa Yoshida, Tomoaki Kawaguchi, Toshiro Matsui, Anti-prediabetic effect of rose hip (Rosa canina) extract in spontaneously diabetic Torii rats, Journal of the Science of Food and Agriculture, 10.1002/jsfa.8254, 97, 12, 3923-3928, 2017.09, BACKGROUND: Prediabetes, a high-risk state for developing diabetes showing impaired glucose tolerance but a normal fasting blood glucose level, has an increasing prevalence worldwide. However, no study investigating the prevention of impaired glucose tolerance at the prediabetic stage by anti-diabetic functional foods has been reported. Thus, the present study aimed to evaluate the anti-prediabetic effect of rose hip in a prediabetic rat model. RESULTS: Spontaneously diabetic Torii (SDT) rats were supplemented with hot-water extract of rose hip at a dose of 100 mg kg–1 body weight day–1 for 12 weeks. The results obtained showed that the supplementation of rose hip extract improved impaired glucose tolerance, promoted insulin secretion, preserved pancreatic beta-cell function and suppressed plasma advanced glycation end-products formation of methylglyoxal-derived hydroimidazolone (MG-H1) residue and Nϵ-carboxymethyl-lysine residues (e.g. MG-H1, control: 465.5 ± 43.8 versus rose hip: 59.1 ± 13.0 pmol mg protein–1, P < 0.05) in SDT rats at the prediabetic stage (12–20 weeks old). CONCLUSION: The present study provides the first evidence showing that a hot-water extract of rose hip could exert an anti-prediabetic effect in a rat model..
8. Vu Thi Hanh, Weilin Shen, Mitsuru Tanaka, Aino Siltari, Riita Korpela, Toshiro Matsui, Effect of Aging on the Absorption of Small Peptides in Spontaneously Hypertensive Rats, Journal of Agricultural and Food Chemistry, 10.1021/acs.jafc.7b01727, 65, 29, 5935-5943, 2017.07, In the present study, we aimed to evaluate the effect of aging on the absorption of small peptides in spontaneously hypertensive rats (SHRs). Three kinds of dipeptides, glycyl-sarcosine (Gly-Sar), Trp-His, and captopril (a dipeptidomimetic drug), a Gly-Sar-Sar tripeptide, a Gly-Sar-Sar-Sar tetrapeptide, and a Gly-Sar-Sar-Sar-Sar pentapeptide were administered at doses of 10 mg/kg each to 8- and 40-week-old SHRs. The peptides were all detected in their intact forms in the blood. There was a significantly promoted absorption of di/tripeptides in aged SHRs compared with young SHRs. In contrast, the absorption of tetra/pentapeptides was not affected by aging. PepT1 expression in the mid-jejunum was significantly increased in 40-week-old SHRs compared with 8-week-old SHRs, whereas aging did not alter the expression of claudin-1, a tight junction related protein. Thus, the present results suggest that SHR aging may enhance the absorption of di/tripeptides through the enhanced PepT1 transport route, although oligopeptides may be absorbed in an age-independent manner..
9. Gonzalo Miyagusuku-Cruzado, Naoki Morishita, Keiichi Fukui, Norihiko Terahara, Toshiro Matsui, Anti-prediabetic effect of 6-O-caffeoylsophorose in prediabetic rats and its stimulation of glucose uptake in L6 Myotubes, Food Sci. Technol. Res., 23, 3, 449-456, 2017.06.
10. Ryoko Yamamoto, Ayaka Iida, Ken Tanikawa, Hideki Shiratsuchi, Masaaki Tokuda, Toshiro Matsui, Tsuyoshi Nakamura, Dietary D-allose ameliorates hepatic inflammation in mice with non-alcoholic steatohepatitis, Food Sci. Technol. Res., 23, 2, 319-327, 2017.04.
11. Kaustav Majumder, Toshihiko Fukuda, Hua Zhang, Takeo Sakurai, Yoshifumi Taniguchi, Hikaru Watanabe, Hitoshi Mitsuzumi, Toshiro Matsui, Yoshinori Mine, Intervention of isomaltodextrin mitigates intestinal inflammation in a dextran sodium sulfate-induced mouse model of colitis via inhibition of toll-like receptor-4, Journal of Agricultural and Food Chemistry, 10.1021/acs.jafc.6b04903, 65, 4, 810-817, 2017.02, Isomaltodextrin (IMD), a highly branched α-glucan, is a type of resistant starch. Earlier studies have indicated that polysaccharides could prevent inflammation and can be effective in reducing the complications of chronic gastrointestinal diseases such as inflammatory bowel disease (IBD). Therefore, the aim of the present study was to evaluate the anti-inflammatory effect of IMD in dextran sodium sulfate (DSS)-induced colitis in a mouse model. IMD (0.5, 1.0, 2.5, and 5.0% (w/v)) was given orally for 23 days to female Balb/c mice, and then 5% DSS was administered to induce colitis (from day 15 onward to the end of the trial). IMD could not prevent DSS-induced weight loss or colon shortening. However, IMD could reduce inflammatory cytokines, TNF-α and IL-6, in the colon. Gene expression indicated the tendency of IMD to suppress pro-inflammatory cytokines IL-1β, MCP-1, and IL-17 and to increase an anti-inflammatory cytokine, IL-10. Further study revealed that the antiinflammatory action of IMD mediates through inhibition of the expression of Toll-like receptor-4..
12. Toshihiko Fukuda, Kaustav Majumder, Hua Zhang, Toshiro Matsui, Yoshinori Mine, Adenine has an anti-inflammatory effect through the activation of adenine receptor signaling in mouse macrophage, Journal of Functional Foods, 10.1016/j.jff.2016.11.013, 28, 235-239, 2017.01, It has previously demonstrated that adenine (6-amino-6H-purine) exhibited a vasoactive effect in contracted aorta. The adenine receptor (AdeR) has recently been identified as a G protein coupled purinergic receptor in diverse organs. It has been suggested that adenine acts as a signaling molecule through the activation of AdeR. The present study investigated the effect of adenine on endotoxin-stimulated mouse macrophages (RAW 264.7 cells) and focused on the AdeR signaling pathway. RAW 264.7 cells were treated with adenine and stimulated with lipopolysaccharide (LPS, Toll-like receptor 4 agonist) from Escherichia coli. Adenine inhibited tumor necrosis factor (TNF)-α secretion in RAW 264.7 cells. The inhibition by adenine was significantly attenuated in the presence of either adenyl cyclase (AC) or protein kinase A (PKA) inhibitors. Furthermore, adenine restored AdeR gene expression. These results firstly demonstrated that adenine acts as an anti-endotoxin compounds through a AdeR/AC/PKA signaling cascade..
13. Thanutchaporn Kumrungsee, Sayaka Akiyama, Jian Guo, Mitsuru Tanaka, Matsui Toshiro, Identification of peptides in wheat germ hydrolysate that demonstrate calmodulin-dependent protein kinase II inhibitory activity, FOOD CHEMISTRY, 10.1016/j.foodchem.2016.06.059, 213, 329-335, 2016.12.
14. THuu-Nghi Nguyen, Mitsuru Tanaka, Genki Komabayashi, Matsui Toshiro, The photobase generator nifedipine as a novel matrix for the detection of polyphenols in matrix-assisted laser desorption/ionization mass spectrometry, JOURNAL OF MASS SPECTROMETRY, 10.1002/jms.3805, 51, 10, 748-756, 2016.10.
15. Toshihiko Fukuda, Takanori Kuroda, Miki Kono, Mai Hyoguchi, Satoshi Tajiri, Mitsuru Tanaka, Yoshinori Mine, Matsui Toshiro, Adenine attenuates the Ca2+ contraction-signaling pathway via adenine receptor-mediated signaling in rat vascular smooth muscle cells, NAUNYN-SCHMIEDEBERGS ARCHIVES OF PHARMACOLOGY, 10.1007/s00210-016-1264-0, 389, 9, 999-1007, 2016.09.
16. Thanutchaporn Kumrungsee, Sayaka Akiyama, Tomomi Saiki, Mitsuru Tanaka, Masao Omae, Kazuhiro Hamasawa, Matsui Toshiro, Vasorelaxation effect of 5’-methylthioadenosine obtained from Candida utilis yeast extract though the suppression of intracellular Ca2+ concentration in rat isolated aorta, JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, 64, 17, 3362-3370, 2016.07.
17. Akiko Mizokami, DaGuang Wang, Genki Komabayashi, Mitsuru Tanaka, Jing Gao, Hiroshi Takeuchi, Matsui Toshiro, Hirata Masato, An extract from pork bones containing osteocalcin improves glucose metabolism in mice by oral administration., Bioscience, Biotechnology, and Biochemistry, 10.1080/09168451.2016.1214530, 80, 11, 2176-2183, 2016.07.
18. Kazuki Motoyasu, Takashi Ichinose, Akane Nakahara, Mitsuru Tanaka, Matsui Toshiro, Shigeki Furuya, The dipeptides Ile-Tyr and Ser-Tyr exert distinct effects on catecholamine metabolism in the mouse brainstem, Int. J. Peptides, 2016, 1-5, 2016.06.
19. Toshihiko Fukuda, Kaustav Majumder, Hua Zhang, Patricia V Turner, Matsui Toshiro, Yoshinori Mine, Adenine Inhibits TNF-alpha Signaling in Intestinal Epithelial Cells and Reduces Mucosal Inflammation in a Dextran Sodium Sulfate-Induced Colitis Mouse Model, JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, 10.1021/acs.jafc.6b00665, 64, 21, 4227-4234, 2016.06.
20. Jian Guo, Naoto Hirasaki, Yuji Miyata, Kazunari Tanaka, TakashiTanaka, Xiao Wu, Yusuke Tahara, Kiyoshi Toko, Matsui Toshiro, Evaluating the Reduced Hydrophobic Taste Sensor Response of Dipeptides by Theasinensin A by Using NMR and Quantum Mechanical Analyses, PLOS ONE, 10.1371/journal.pone.0157315, 11, 6, e0157315, 2016.06, 重合カテキンであるテアシネンシンAが苦みペプチドである各種のトリプトファン含有ジペプチドの苦み応答を抑制し、かつ園現象は溶液内での両者の複合体形成であることをin vitroおよびin silico解析によって突き止めたこと。.
21. Hirosuke Inoue, Hisanori Nishio, Hidetoshi Takada, Etsuko Nanishi, Mitsuho Onimaru, Si Jing Chen, Matsui Toshiro, Toshiro Hara, Activation of Nod1 signaling induces fetal growth restriction and death through fetal and maternal vasculopathy, Journal of Immunology, 196, 2779-2787, 2016.05.
22. Thanutchaporn Kumrungsee, Sayaka Akiyama, Tomomi Saiki, Masato Omae, Kazuhiro Hamasawa, Toshiro Matsui, Vasorelaxant effect of 5′-methylthioadenosine obtained from candida utilis yeast extract through the suppression of intracellular Ca2+ concentration in isolated rat aorta, Journal of Agricultural and Food Chemistry, 10.1021/acs.jafc.6b00679, 64, 17, 3362-3370, 2016.05, Our study is the first to demonstrate the vasorelaxant effect of Candida utilis yeast extract on rat aorta (EC50 of 7.2 ± 3.2 mg/mL). Among five identified compounds, 5′-methylthioadenosine (MTA) exhibited comparable vasorelaxant effect (EC50 of 190 ± 40 μM) with adenosine, a known vasodilator, on 1 μM phenylephrine (PE)-contracted Sprague-Dawley rat aortic rings. MTA induced vasorelaxation in an endothelium-independent manner and independent of the adenosine receptors. MTA reduced a CaCl2-induced vasocontraction stimulated by 1 μM PE, whereas the effect was abolished in a 60 mM KCl-induced vasocontraction. This indicates that MTA was not involved in the suppression of extracellular Ca2+ influx. MTA significantly (P < 0.01) attenuated the PE-induced activation of calmodulin-dependent kinase II (CaMK II) in aortic rings and inhibited the phosphorylation of L-type Ca2+ channel (VDCC). In conclusion, the underlying mechanism(s) of MTA-induced vasorelaxation involves the inhibition of Ca2+/CaMK II/VDCC phosphorylation pathway, resulting in the suppression of intracellular Ca2+ concentration in aortic rings..
23. Seong-Min Hong, Mitsuru Tanaka, Riho Koyanagi, Weilin Shen, Matsui Toshiro, Structural Design of Oligopeptides for Intestinal Transport Model, JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, 10.1021/acs.jafc.6b00279, 64, 10, 2072-2079, 2016.03.
24. Hirosuke Inoue, Hisanori Nishio, Hidetoshi Takada, Yasunari Sakai, Etsuro Nanishi, Masayuki Ochiai, Mitsuho Onimaru, Si Jing Chen, Toshiro Matsui, Toshiro Hara, Activation of Nod1 signaling induces fetal growth restriction and death through fetal and maternal vasculopathy, Journal of Immunology, 10.4049/jimmunol.1500295, 196, 6, 2779-2787, 2016.03, Intrauterine fetal growth restriction (IUGR) and death (IUFD) are both serious problems in the perinatal medicine. Fetal vasculopathy is currently considered to account for a pathogenic mechanism of IUGR and IUFD. We previously demonstrated that an innate immune receptor, the nucleotide-binding oligomerization domain-1 (Nod1), contributed to the development of vascular inflammations in mice at postnatal stages. However, little is known about the deleterious effects of activated Nod1 signaling on embryonic growth and development. We report that administration of FK565, one of the Nod1 ligands, to pregnant C57BL/6 mice induced IUGR and IUFD. Mass spectrometry analysis revealed that maternally injected FK565 was distributed to the fetal tissues across placenta. In addition, maternal injection of FK565 induced robust increases in the amounts of CCL2, IL-6, and TNF proteins as well as NO in maternal, placental and fetal tissues. Nod1 was highly expressed in fetal vascular tissues, where significantly higher levels of CCL2 and IL-6 mRNAs were induced with maternal injection of FK565 than those in other tissues. Using Nod1-knockout mice, we verified that both maternal and fetal tissues were involved in the development of IUGR and IUFD. Furthermore, FK565 induced upregulation of genes associated with immune response, inflammation, and apoptosis in fetal vascular tissues. Our data thus provided new evidence for the pathogenic role of Nod1 in the development of IUGR and IUFD at the maternal-fetal interface..
25. Vu Thi Hanh, Yutaro Kobayashi, Motohiro Maebuchi, Toshihiro Nakamori, Mitsuru Tanaka, Matsui Toshiro, Quantitative mass spectrometric analysis of dipeptides in protein hydrolysate by a TNBS derivatization-aided standard addition method, FOOD CHEMISTRY, 10.1016/j.foodchem.2015.05.053, 190, 345-350, 2016.01.
26. Yusuke Ushida, Boonyapichest Chutinan, Hiroyuki Suganuma, Mitsuru Tanaka, Matsui Toshiro, Paracellular Transport of Sulforaphane across Caco-2 Cell Monolayers, FOOD SCIENCE AND TECHNOLOGY RESEARCH, 10.3136/fstr.22.127, 22, 1, 127-134, 2016.01.
27. Jian Zhao, Aki Suyama, Hsuan Chung, Toshihiko Fukuda, Mitsuru Tanaka, Matsui Toshiro, Ferulic acid enhances nitric oxide production through up-regulation of argininosuccinate synthase in inflammatory human endothelial cells, LIFE SCIENCES, 10.1016/j.lfs.2015.12.044, 145, 224-232, 2016.01.
28. Kazuki Moriyasu, Takashi Ichinose, Akane Nakahata, Mitsuru Tanaka, Toshiro Matsui, Shigeki Furuya, The Dipeptides Ile-Tyr and Ser-Tyr Exert Distinct Effects on Catecholamine Metabolism in the Mouse Brainstem, International Journal of Peptides, 10.1155/2016/6020786, 2016, 2016.01, Catecholamine synthesis and transmission in the brain are influenced by the availability of Tyr in the body. In this study, we compared the effects of oral administration of Tyr-containing dipeptides Ile-Tyr, Ser-Tyr, and Tyr-Pro with Tyr alone on catecholamine metabolism in the mouse brainstem. Among these dipeptides, Ile-Tyr administration led to increases in dopamine, the dopamine metabolites homovanillic acid, and 3,4-dihydroxyphenylacetic acid, compared to administration of Ser-Tyr, Tyr-Pro, or Tyr alone. In comparison, administration of Ser-Tyr induced significantly increasing noradrenaline turnover, while Tyr-Pro administration suppressed dopamine turnover. Therefore, oral administration of Ile-Tyr, Ser-Tyr, and Tyr-Pro differentially affected metabolism of dopamine and noradrenaline. These observations strongly suggest that Tyr-containing dipeptides exert distinct effects on catecholamine metabolism in the brainstem when ingested orally..
29. Toshihiko Fukuda, Takanori Kuroda, Miki Kono, Mai Hyoguchi, Mitsuru Tanaka, Matsui Toshiro, Augmentation of ferulic acid-induced vasorelaxation with aging and its structure importance in thoracic aorta of spontaneously hypertensive rats, NAUNYN-SCHMIEDEBERGS ARCHIVES OF PHARMACOLOGY, 10.1007/s00210-015-1171-9, 388, 10, 1113-1117, 2015.10.
30. Toshiro Matsui, Condensed catechins and their potential health-benefits, European Journal of Pharmacology, 10.1016/j.ejphar.2015.09.017, 765, 495-502, 2015.10, Condensed catechins are commonly present in fermented tea, and are produced by the oxidation of monomeric catechins. Due to their auto-oxidation, catechins have diverse structural features, including different binding modes and degrees of polymerization. Because of their structural complexity, their physiological functions and possible health-benefits have not yet been fully investigated. This review focuses on the physiological potentials of dimeric and trimeric catechins in the intestine (regulation of absorption across the intestinal membrane), blood vessels (vasorelaxation in vessel regulation), and muscle organs (promotion of glucose uptake resulting in an anti-diabetic effect). Furthermore, the roles of non-absorbable theaflavins (dimeric catechins), absorbable theasinensins (dimeric catechins), and absorbable procyanidins (dimeric and trimeric catechins) on target organs are discussed..
31. Takashi Ichinose, Kazuki Moriyasu, Akane Nakahara, Mitsuru Tanaka, Matsui Toshiro, Shigeki Furuya, Orally administrated dipeptide Ser-Tyr efficiently stimulates noradrenergic turnover in the mouse brain, BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, 10.1080/09168451.2015.1044932, 79, 9, 1542-1547, 2015.09.
32. Mitsuru Tanaka, Seong-Min Hong, Sayaka Akiyama, Qing-Qiang Hu, Matsui Toshiro, Visualized absorption of anti-atherosclerotic dipeptide, Trp-His, in Sprague-Dawley rats by LC-MS and MALDI-MS imaging analyses, MOLECULAR NUTRITION & FOOD RESEARCH, 10.1002/mnfr.201500075, 59, 8, 1541-1549, 2015.08.
33. Ruge Cao, Yutaro Kobayashi, Airi Nonaka, Yuji Miyata, Kazunari Tanaka, Takashi Tanaka, Matsui Toshiro, NMR Spectroscopic and Quantum Mechanical Analyses of Enhanced Solubilization of Hesperidin by Theasinensin A, PHARMACEUTICAL RESEARCH, 10.1007/s11095-015-1621-6, 32, 7, 2301-2309, 2015.07.
34. Si Jing Chen, Chiwa Aikawa, Risa Yoshida, Matsui Toshiro, Methylglyoxal-derived hydroimidazolone residue of plasma protein can behave as a predictor of pre-diabetes in Spontaneously Diabetic Torii rats, Physiological Reports, doi10.14814/phy2.12477, 3, 7, e12477, 2015.07.
35. Yutaro Kobayashi, Jennifer Kovacs-Nolan, Toshiro Matsui, Yoshinori Mine, The Anti-atherosclerotic Dipeptide, Trp-His, Reduces Intestinal Inflammation through the Blockade of L-Type Ca2+ Channels, Journal of Agricultural and Food Chemistry, 10.1021/acs.jafc.5b01682, 63, 26, 6041-6050, 2015.07, Trp-His, the anti-atherosclerotic dipeptide, exerted an antiproliferative effect on vascular smooth muscle cells by L-type Ca2+ channel blocker-like effect. The beneficial potential by the blockade of Ca2+ channels on chronic intestinal inflammation, including inflammatory bowel disease (IBD), is unclear. Trp-His (100 or 250 mg/kg body weight/day) was administered for 14 days to BALB/c mice, and 5% dextran sodium sulfate (DSS) was administered to induce colitis in the last 7 days. Trp-His reduced DSS-induced typical colitis symptoms and cytokine expression in the colon. Trp-His inhibited interleukin (IL)-8 secretion in tumor necrosis factor (TNF)-α-stimulated HT-29 cells. The inhibitory effect of Trp-His, as well as that of Ca2+ channel blockers, was impaired by the presence of Ca2+ channel agonist Bay K 8644. The TNF-α-induced activation of mitogen-activated protein kinases (MAPKs) and IκBα were decreased by Trp-His. These results indicated that the anti-inflammatory effect of Trp-His may be involved in the blockade of L-type Ca2+ channels..
36. Yutaro Kobayashi, Jennifer Kovacs-Nolan, Matsui Toshiro, Yoshinori Mine, The anti-atherosclerotic di-peptide, Trp-His, reduces intestinal inflammation through the blockade of L-type Ca2+ channels, JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, 63, 6, 6041-6050, 2015.06.
37. Ruge Cao, Airi Nonaka, Fusae Komura, Matsui Toshiro, Application of diffusion ordered-H-1-nuclear magnetic resonance spectroscopy to quantify sucrose in beverages, FOOD CHEMISTRY, 10.1016/j.foodchem.2014.08.105, 171, 8-12, 2015.03.
38. Si Jing Chen, Chiwa Aikawa, Matsui Toshiro, Qantitative analysis of methylglyoxal, glyoxal and free advanced glycation end-products in plasma of Wistar rats during oral glucose tolerance test, Biological Pharmacology Bulletin, 38, 2, 336-339, 2015.02.
39. Yutaro Kobayashi, Prithy Rupa, Jennifer Kovacs-Nolan, Patricia V Turner, Matsui Toshiro, Yoshinori Mine, Oral Administration of Hen Egg White Ovotransferrin Attenuates the Development of Colitis Induced by Dextran Sodium Sulfate in Mice, JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, 10.1021/jf505248n, 63, 5, 1532-1539, 2015.02.
40. Si Jing Chen, Chiwa Aikawa, Toshiro Matsui, Quantitative analysis of methylglyoxal, glyoxal and free advanced glycation end-products in the plasma of wistar rats during the oral glucose tolerance test, Biological and Pharmaceutical Bulletin, 10.1248/bpb.b14-00698, 38, 2, 336-339, 2015.02, The purpose of this study was to gain insight into the production behavior of free adducts of advanced glycation end-products (AGEs) in Wistar rats under acute hyperglycemic conditions. Five AGE-free adducts as well as their precursors (i.e., highly reactive carbonyl intermediates of methylglyoxal and glyoxal) in rat plasma were quantitatively determined at greater than nanomolar levels using the liquid chromatography/ tandem mass spectrometry method coupled with 2,4,6-trinitrobenzene sulfonate and 2,3-diaminonaphthalene derivatization techniques. An oral glucose (2 g/kg dose) tolerance test to 10-week-old Wistar rats provided evidence that the plasma levels of diabetes-related metabolites did not change acutely within 120 min, irrespective of increasing blood glucose levels..
41. Ha-Young Park, Yuri Kunitake, Naoto Hirasaki, Mitsuru Tanaka, Matsui Toshiro, Theaflavins enhance intestinal barrier of Caco-2 Cell monolayers through the expression of AMP-activated protein kinase-mediated Occludin, Claudin-1, and ZO-1, BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, 10.1080/09168451.2014.951027, 79, 1, 130-137, 2015.01.
42. Hisayuki Nakayama, Naho Yuito, Yuji Miyata, Kei Tamaya, Takashi Tanakna, Yoshinori Saito, Matsui Toshiro, Sadayuki Aramaki, Yasuo Nagata, Shizuka Tamaru, Kazunari Tanaka, Effects of a new fermented tea made with third crop green tea (Camellia sinensis) leaves and unripe Satsuma Mandarin (Citrus unshiu) fruits on serum and liver lipid concentrations in rats, Food Science and Technology Research, 21, 1, 77-86, 2015.01.
43. Jiang Guo, Tomomi Saiki, Kumrungsee Thanutchaporn, Wanying Liu, Akihiro Shimura, Matsui Toshiro, Elution Profile of Di-peptides on a Sulfonated Ethylstyrene-Divinylbenzene Copolymer Resin Column by High-performance Liquid Chromatography, ANALYTICAL SCIENCES, 31, 1, 45-50, 2015.01.
44. Jian Guo, Tomomi Saiki, Kumrungsee Thanutchaporn, Wanying Liu, Akihiro Shimura, Toshiro Matsui, Elution profile of di-peptides on a sulfonated ethylstyrene-divinylbenzene copolymer resin column by high-performance liquid chromatography, Analytical Sciences, 10.2116/analsci.31.45, 31, 1, 45-50, 2015.01, This study investigates the characteristics of a partially sulfonated ethylstyrene-divinylbenzene copolymer for the separation of di-peptides by high-performance liquid chromatography. Di-peptides (VE, VA, VH, VK, and VR) with different isoelectric points (pI, 4.0 to 9.7) and log P values (-1.63 to -0.72) were used to optimize the separation conditions of the columns packed with sulfonated copolymer resin. The retention factor (k) of the di-peptides on the column with a 0.81 wt% sulfo group content decreased with increasing concentrations of phosphate salts (2.5-20 mmol L-1) in the mobile phase. The complete separation of the five di-peptides was obtained with a gradient of 10% methanol containing 5 mmol L-1 NaH2PO4 (pH 4.8) to 50% methanol containing 5 mmol L-1 NaH2PO4 (pH 8.9) for 60 min at 0.5 mL min-1 at 50°C. Under the optimal conditions, a good relationship between the k and pI values of the di-peptides, with the exception of VE (pI 4.0), was observed, suggesting that the retention of the di-peptides on the column packed with sulfonated copolymer resin was dependent on the pI value, when it was greater than 5. The log P value also influenced the separation characteristics of the column; peptides possessing the same pI value (6.4 for GH, VH, IH, and FH) showed a higher retention on the column with increasing log P values. In conclusion, the prototype sulfonated ethylstyrene-divinylbenzene copolymer column was applicable for the separation of basic di-peptides, and the separation depended on the pI and hydrophobicity of the di-peptides. 2014..
45. Hisayuki Nakayama, Naho Yuito, Yuji Miyata, Kei Tamaya, Takashi Tanaka, Yoshinori Saito, Toshiro Matsui, Sadayuki Aramaki, Yasuo Nagata, Shizuka Tamaru, Kazunari Tanaka, Hypolipidemic property of a new fermented tea made with third crop green tea (Camellia sinensis) leaves and unripe satsuma mandarin (Citrus unshiu) fruits, Food Science and Technology Research, 10.3136/fstr.21.77, 21, 1, 77-86, 2015, We manufactured a new fermented tea by tea-rolling processing of third crop green tea (Camellia sinensis) leaves and unripe satsuma mandarin (Citrus unshiu) fruits, and investigated the effects of feeding the tea extract on serum and liver lipid concentrations in rats. The tea extract contained narirutin and hesperidin from unripe satsuma mandarin fruits, catechins from green tea leaves, and black tea polyphenols produced by oxidation of catechins. The fermented tea extract inhibited pancreatic lipase activity in vitro. When rats were fed diets supplemented with the freeze-dried tea extract (0.50% or 0.75%) for 4 weeks, hepatic triglyceride and cholesterol concentrations were reduced in a dose-dependent manner, and the reductions were significant in rats fed diet composed of 0.75% tea extract compared to those fed the control diet. These results suggest that the tea produced by mixing third crop green tea leaves and unripe satsuma mandarin fruits has a hypolipidemic property..
46. Si Jing Chen, Chiwa Aikawa, Risa Yoshida, Toshiro Matsui, Methylglyoxal-derived hydroimidazolone residue of plasma protein can behave as a predictor of prediabetes in Spontaneously Diabetic Torii rats, Physiological Reports, 10.14814/phy2.12477, 3, 8, 2015, Prediabetes, typically defined as impaired glucose tolerance and/or impaired fasting blood glucose, is a high-risk state of developing diabetes. The association of diabetes-related metabolites with prediabetes has not been investigated intensively. This study aimed to get insights into the metabolic behaviors of some typical diabetes-related metabolites in plasma of male Spontaneously Diabetic Torii (SDT) rats during pathogenic progress of diabetes and to assess in vivo if the variation in these metabolites related to the progression of prediabetic stage. To address this question, SDT rats and Sprague Dawley (SD) rats as control were maintained from the age of 7 to 25 weeks. Five typical advanced glycation end products (AGEs) residue of plasma protein and their free adducts were determined by liquid chromatography with tandem mass detection over the duration of the investigation. The SDT rats exhibited impaired glucose tolerance since the age of 12 weeks and developed diabetes with significantly elevated fasting glucose levels after 22 weeks. At the prediabetic stage (12–21 weeks), no significant differences were observed on AGEfree adducts levels of SDT rats compared with SD rats. However, methylglyoxal- derived hydroimidazolone (MG-H1) residue contents of plasma protein were significantly elevated in SDT rats at the age of 16 weeks, whereas other AGE residues of plasma protein did not show marked difference. The present study has revealed significant increase in MG-H1 residue content of plasma protein at the prediabetic stage of a spontaneously diabetic rat model, irrespective of unaltered fasting blood glucose and constant plasma levels of other AGEs..
47. Mitsuru Tanaka, Eiji Tanaka, Noe Obinata, Toshiro Matsui, Visualization of tocopherol acetate absorbed inside laminated films by a matrix-assisted laser desorption/ionization-imaging mass spectrometry, Food Science and Technology Research, 10.3136/fstr.21.821, 21, 6, 821-826, 2015, The aim of this study was to visualize the sorption of tocopherol acetate as a penetrant into polymer films. A matrix-assisted laser desorption/ionization-imaging mass spectrometry (MALDI-IMS) technique was used to visualize the distribution of tocopherol acetate in films during the migration process. A phytic acid-aided MALDIIMS using 2',4',6'-trihydroxyacetophenone as a matrix allowed us to successfully visualize the absorbed tocopherol acetate in both ethylene-vinyl acetate copolymer (EVA) and low-density polyethylene (LDPE) films after 1 weekstorage of tocopherol acetate at 40°C. The IMS technique allowed us to also visualize the actual distribution of tocopherol acetate inside the EVA/barrier/EVA laminated films, in which tocopherol acetate sorption was blocked at the barrier layer..
48. Minoru Soga, Ayaka Ohashi, Megumi Taniguchi, Toshiro Matsui, Takanori Tsuda, The di-peptide Trp-His activates AMP-activated protein kinase and enhances glucose uptake independently of insulin in L6 myotubes, FEBS Open Bio, 10.1016/j.fob.2014.10.008, 4, 898-904, 2014.12, The di-peptide Trp-His (WH) has vasorelaxant and anti-atherosclerotic functions. We hypothesized that WH has multiple biological functions and may aid AMP-activated protein kinase (AMPK) activation and affect the glucose transport system in skeletal muscle.First, we examined whether WH or His-Trp (HW) can activate AMPKα. Treatment of L6 myotubes with WH or HW significantly increased phosphorylation of AMPKα. WH activated AMPK independently of insulin and significantly increased glucose uptake into L6 myotubes following translocation of glucose transporter 4 (Glut4) to the plasma membrane. This activation was induced by the LKB1 pathway but was independent of changes in intracellular Ca2+ levels and the Ca2+/calmodulin-dependent kinase pathway. L6 myotubes express only one type of oligopeptide transporter, peptide/histidine transporter 1 (PHT1, also known as SLC15a4), and WH is incorporated into cells and activates AMPKα following PHT1-mediated cell uptake.These findings indicate that (1) WH activates AMPK and insulin independently enhances glucose uptake following translocation of Glut4 to the plasma membrane, (2) activation of AMPKα by WH is mediated by the LKB1 pathway, without altering the Ca2+-dependent pathway, and (3) L6 myotubes express only one type of peptide transporter (PHT1; SLC15a4), which incorporates WH into cells to activate AMPKα..
49. Woo Hyung Lee, Hong Min Wu, Chan Gyu Lee, Dae Il Sung, Hye Jung Song, Matsui Toshiro, Han Bok Kim, Sang Geon Kim, Specific oligopeptides in fermented soybean extract from Glycine max inhibit NF-κB-dependent iNOS and cytokine induction by TLR ligands, Journal of Medicinal Foods, 17, 11, 1239-1246, 2014.11.
50. Soga Minoru, Ohashi Ayaka, Taniguchi Emi, Matsui Toshiro, Tsuda Takanori, The di-peptide Trp-His activates AMP-activated protein kinase and insulin-independently enhances glucose uptake in L6 myotubes, FEBS Open Bio, 4, 898-904, 2014.11.
51. Woo H.yung Lee, Hong M.in Wu, Chan G.yu Lee, Dae I.l. Sung, Hye J.ung Song, Toshiro Matsui, Han B.ok Kim, Sang G.eon Kim, Specific oligopeptides in fermented soybean extract inhibit NF-κB-dependent iNOS and cytokine induction by toll-like receptor ligands, Journal of Medicinal Food, 10.1089/jmf.2013.3070, 17, 11, 1239-1246, 2014.11, The ethanol extract of fermented soybean from Glycine max (chungkookjang, CHU) has been claimed to have chemopreventive and cytoprotective effects. In the present study, we examined the inhibitory effect of CHU on inducible nitric oxide synthase (iNOS) and cytokine induction by toll-like receptor (TLR) ligands treatment and attempted to identify the responsible active components. Nitric oxide (NO) content and iNOS levels in the media or RAW264.7 cells were measured using the Griess reagent and real-time polymerase chain reaction assays. CHU treatment inhibited NO production and iNOS induction elicited by lipopolysaccharide (LPS, TLR4L) in a concentration-dependent manner. Tumor necrosis factor-α and interleukin-6 productions were also diminished. Peptidoglycans (TLR2/6L) and CpG-oligodeoxynucleotides (TLR9L) from CHU inhibited iNOS induction, but not poly I:C (TLR3L) or loxoribine (TLF7L). The anti-inflammatory effect resulted from the inhibition of nuclear factor-kappa B (NF-κB) through the inhibition of inhibitory-κB degradation. Of the representative components in CHU, specific oligopeptides (AFPG and GVAWWMY) had the ability to inhibit iNOS induction by LPS, whereas others failed to do so. Daidzein, an isoflavone used for comparative purposes, was active at a relatively higher concentration. In an animal model, oral administration of CHU to rats significantly diminished carrageenan-induced paw edema and iNOS induction. Our results demonstrate that CHU has anti-inflammatory effects against TLR ligands by inhibiting NF-κB activation, which may result from specific oligopeptide components in CHU. Since CHU is orally effective, dietary applications of CHU and/or the identified oligopeptides may be of use in the prevention of inflammatory diseases..
52. Kumrungsee Thanutchaporn, Saiki Tomomi, Akiyama Sayaka, Nakashima Kentaro, Mitsuru Tanaka, Kobayashi Yutaro, Matsui Toshiro, Inhibition of calcium-calmodulin complex formation by vasorelaxant basic dipeptides demonstrated by in vitro and in silico analyses, BIOCHIMICA ET BIOPHYSICA ACTA-GENERAL SUBJECTS, 10.1016/j.bbagen.2014.07.020, 1840, 10, 3073-3078, 2014.10.
53. Kovacs-Nolan Jennifer, Rupa Prithy, Matsui Toshiro, Mitsuru Tanaka, Konishi Toni, Sauchi Yusuke, Sato Kenji, Ono Shin, Mine Yoshinori, In Vitro and ex Vivo Uptake of Glutathione (GSH) across the Intestinal Epithelium and Fate of Oral GSH after in Vivo Supplementation, JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, 10.1021/jf503257w, 62, 39, 9499-9506, 2014.10.
54. Zhao Jian, Suyama Aki, Mitsuru Tanaka, Matsui Toshiro, Ferulic acid enhances the vasorelaxant effect of epigallocatechin gallate in tumor necrosis factor-alpha-induced inflammatory rat aorta, JOURNAL OF NUTRITIONAL BIOCHEMISTRY, 10.1016/j.jnutbio.2014.03.013, 25, 7, 807-814, 2014.07.
55. Shimamura, Tomoko, Sumikura Yoshihiro, Yamazaki Takeshi, Tada Atsuko, Kashiwagi Takehiro, Ishikawa Hiroya, Matsui Toshiro, Sugimoto Naoki, Akiyama Hiroshi, Ukeda Hiroyuki, Applicability of the DPPH Assay for Evaluating the Antioxidant Capacity of Food Additives - Inter-laboratory Evaluation Study, ANALYTICAL SCIENCES, 30, 7, 717-721, 2014.07.
56. Kumrungsee Thanutchaporn, Wang Zheng-Quan, Matsumura Shinya, Saiki Tomomi, Mitsuru Tanaka, Matsui Toshiro, Identification of peptides from soybean protein, glycinin, possessing suppression of intracellular Ca2+ concentration in vascular smooth muscle cells, FOOD CHEMISTRY, 10.1016/j.foodchem.2013.11.143, 152, 218-224, 2014.06.
57. Cao Ruge, Komura Fusae, Nonaka Airi, Kato Takeshi, Fukumashi Junji, Matsui Toshiro, Quantitative analysis of D-(+)-glucose in fruit juices using diffusion ordered-1H nuclear magnetic resonance spectroscopy, Analytical Sciences, 30, 3, 383-388, 2014.03.
58. Ruge Cao, Fusae Komura, Airi Nonaka, Takeshi Kato, Junji Fukumashi, Toshiro Matsui, Quantitative analysis of D-(+)-glucose in fruit juices using diffusion ordered-1H nuclear magnetic resonance spectroscopy, Analytical Sciences, 10.2116/analsci.30.383, 30, 3, 383-388, 2014.03, This study works on D-(+)-glucose quantitative analysis using diffusion ordered-quantitative 1H nuclear magnetic resonance spectroscopy (DOSY-qNMR), by which an analyte could be distinguished from interferences based upon a characteristic diffusion coefficient (D) in gradient magnetic fields. The D value of D-(+)-glucose in deuterium oxide at 30°C was 5.6 × 10-10 m2/s at a field gradient pulse of between 5.0 × 10-2 and 3.0 × 10-1 T/m, distinguished from fructose, sucrose and starch. Good linearity (r2 = 0.9998) was obtained between D-(+)-glucose (0.5-20.0 g/L) and the ratio of the resonance area of a-C1 proton (5.21 ppm) in D-(+)-glucose to that of the β-C1 proton (5.25 ppm) in D-glucuronic acid (50.0 g/L) as an internal standard. The DOSY-qNMR method was successfully applied to quantify D-(+)-glucose in orange juice (18.3 ± 1.0 g/L), apple juice (26.3 ± 0.4 g/L) and grape juice (45.6 ± 0.6 g/L); the values agreed well with a conventional F-kit glucose method..
59. Fukuda Toshihiko, Kuroda Takahiro, Kono Miki, Takahisa Miyamoto, Mitsuru Tanaka, Matsui Toshiro, Attenuation of L-Type Ca2+ Channel Expression and Vasomotor Response in the Aorta with Age in Both Wistar-Kyoto and Spontaneously Hypertensive Rats, PLOS ONE, 10.1371/journal.pone.0088975, 9, 2, e88975-e88983, 2014.02.
60. Qiu Ju, Maekawa Kanako, Kitamura Yuko, Miyata Yuji, Tanaka Kazunari, Tanaka Takashi, Soga Minoru, Tsuda Takanori, Matsui Toshiro, Stimulation of glucose uptake by theasinensins through the AMP-activated protein kinase pathway in rat skeletal muscle cells, BIOCHEMICAL PHARMACOLOGY, 10.1016/j.bcp.2013.10.029, 87, 2, 344-351, 2014.01.
61. Tomoko Shimamura, Yoshihiro Sumikura, Takeshi Yamazaki, Atsuko Tada, Takehiro Kashiwagi, Hiroya Ishikawa, Toshiro Matsui, Naoki Sugimoto, Hiroshi Akiyama, Hiroyuki Ukeda, Applicability of the DPPH assay for evaluating the antioxidant capacity of food additives - inter-laboratory evaluation study, Analytical Sciences, 10.2116/analsci.30.717, 30, 7, 717-721, 2014, An inter-laboratory evaluation study was conducted in order to evaluate the antioxidant capacity of food additives by using a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Four antioxidants used as existing food additives (i.e., tea extract, grape seed extract, enju extract, and d-α-tocopherol) and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) were used as analytical samples, and 14 laboratories participated in this study. The repeatability relative standard deviation (RSDr) of the IC50 of Trolox, four antioxidants, and the Trolox equivalent antioxidant capacity (TEAC) were 1.8 - 2.2%, 2.2 - 2.9%, and 2.1 - 2.5%, respectively. Thus, the proposed DPPH assay showed good performance within the same laboratory. The reproducibility relative standard deviation (RSDR) of IC50 of Trolox, four antioxidants, and TEAC were 4.0 - 7.9%, 6.0 - 11%, and 3.7 - 9.3%, respectively. The RSDR/RSDr values of TEAC were lower than, or nearly equal to, those of IC50 of the four antioxidants, suggesting that the use of TEAC was effective for reducing the variance among the laboratories. These results showed that the proposed DPPH assay could be used as a standard method to evaluate the antioxidant capacity of food additives..
62. Seong-Min Hong, Mitsuru Tanaka, Saori Yoshii, Yoshinori Mine, Matsui Toshiro, Enhanced visualization of small peptides absorbed in rat small intestine by phytic-acid-aided MALDI-imaging mass spectrometry, Anal. Chem, 85, 11, 10033-10039, 2013.11.
63. Seong Min Hong, Mitsuru Tanaka, Saori Yoshii, Yoshinori Mine, Toshiro Matsui, Enhanced visualization of small peptides absorbed in rat small intestine by phytic-acid-aided matrix-assisted laser desorption/ionization-imaging mass spectrometry, Analytical Chemistry, 10.1021/ac402252j, 85, 21, 10033-10039, 2013.11, Enhanced visualization of small peptides absorbed through a rat intestinal membrane was achieved by matrix-assisted laser desorption/ionization time-of-flight imaging mass spectrometry (MALDI-IMS) with the aid of phytic acid as a matrix additive. Penetrants through intestinal peptide transporter 1, i.e., glycyl-sarcosine (Gly-Sar, 147.1 m/z) and antihypertensive dipeptide, Val-Tyr (281.2 m/z), were chosen for MALDI-IMS. The signal-to-noise (S/N) ratios of dipeptides Gly-Sar and Val-Tyr were seen to increase by 2.4- and 8.0-fold, respectively, when using a 2′,4′,6′-trihydroxyacetophenone (THAP) matrix containing 5.0 mM phytic acid, instead of the THAP matrix alone. Owing to the phytic-acid-aided MALDI-IMS method, Gly-Sar and Val-Tyr absorbed in the rat intestinal membrane were successfully visualized. The proposed imaging method also provided useful information on intestinal peptide absorption; to some extent, Val-Tyr was rapidly hydrolyzed to Tyr by peptidases located at the intestinal microvillus during the absorption process. In conclusion, the strongly acidic additive, phytic acid, is beneficial for enhancing the visualization of small peptides using MALDI-IMS, owing to the suppression of ionization-interfering salts in the tissue..
64. Eduardo M N Nakashima, Hu Qiang Qing, Mitsuru Tanaka, Toshiro Matsui, Improved detection of di-peptides by liquid chromatography-tandem mass spectrometry with 2,4,6-trinitrobenzene sulfonate conversion, Bioscience, Biotechnology and Biochemistry, 10.1271/bbb.130448, 77, 10, 2094-2099, 2013.11, Highly sensitive detection of small peptides at the pM level was achieved by liquid chromatography-multiple reaction monitoring-tandem mass spectrometry (LCMRM- MS/MS) in combination with the 2,4,6-trinitrobenzene sulfonate (TNBS) conversion technique. Six di-peptides having Tyr at the C-terminal (i.e., Gly-Tyr, Val-Tyr, Met-Tyr, Glu-Tyr, Lys-Tyr and His-Tyr) were subjected to the TNBS-MRM analysis in this study. The TNBS conversion conditions of pH 8.0, 30 °C and 60- min incubation enabled the di-peptides to be successfully converted to a trinitrophenyl (TNP) form with the mass increment of +212 Da. The proposed TNBS-MRM method enabled di-peptide detection that was highly improved by a factor of 3-55 in signal-to-noise ratio due to increased hydrophobicity by the induced TNP moiety. The method also permitted highly sensitive detection of di-peptides with a detection limit of >54 pM (>1:35 fmol/injection), achieving high reproducibility (<5%coefficient of variation) and rapidity (<30 min) by LC-MRM-MS/MS..
65. Eduardo M. N. Nakashima, Hu-Qiang Qing, Tanaka Mitsuru, Matsui Toshiro, Improvement of liquid chromatography-tandem mass spectrometric detection of di-peptides by 2,4,6-trinitrobenzene sulfonate derivatization, Biosci. Biotechnol. Biochem, 77, 10, 2094-2099, 2013.10.
66. Y.Miyata, S.Tamaru, K.Tamaya, Matsui Toshiro, Y.Nagata, K.Tanaka, Theflavins and theasinensin A derived from fermented tea have antihyperglycemic and hypotriacylglycerolemic effects in KK-Ay mice and Sprague-Dawley rats, J. Agric. Food Chem, 61, 10, 9366-9372, 2013.10.
67. Yuji Miyata, Shizuka Tamaru, Takashi Tanaka, Kei Tamaya, Toshiro Matsui, Yasuo Nagata, Kazunari Tanaka, Theflavins and theasinensin A derived from fermented tea have antihyperglycemic and hypotriacylglycerolemic effects in KK-Ay mice and Sprague-Dawley rats, Journal of Agricultural and Food Chemistry, 10.1021/jf400123y, 61, 39, 9366-9372, 2013.10, Although tea polyphenols are reported to improve serum glucose and lipid levels by inhibiting amylase activity and reducing lipid absorption, in vivo data are lacking. We evaluated in vivo the antihyperglycemic and hypotriacylglycerolemic effects of theaflavins (TFs) and theasinensin A (TSA) refined from fermented tea to purities of 12 and 59%, respectively. Feeding male KK-Ay mice diets with 0.1% TFs or TSA for 6 weeks reduced serum glucose levels by >30% compared to a control diet. Rats fed diets containing 0.2% TFs or TSA for 4 weeks had higher fecal fat excretion and 33% lower hepatic triacylglycerol; hepatic fatty acid synthase activity was not affected. Oral administration of TFs or TSA reduced the increase in serum triacylglycerol after an oral bolus of a fat emulsion. These results indicate TFs and TSA induce antihyperglycemic responses in diabetic mice and are hypotriacylglycerolemic in rats by suppressing intestinal fat absorption..
68. Takeda, Junko, Park, Ha-Young, Kunitake, Yuri, Yoshiura, Keiko, Matsui Toshiro, Theaflavins, dimeric catechins, inhibit peptide transport across Caco-2 cell monolayers via down-regulation of AMP-activated protein kinase-mediated peptide transporter PEPT1, FOOD CHEMISTRY, 10.1016/j.foodchem.2012.12.026, 138, 4, 2140-2145, 2013.06.
69. Hoang Lan Phuong, Qiu, Ju, Matsui Toshiro, Kuwahara, Takashi, Fukui, Keiichi, Yoshiyama, Kayo, Matsugano, Kazusato, Terahara, Norihiko, Transepithelial transport of 6-O-caffeoylsophorose across Caco-2 cell monolayers, FOOD CHEMISTRY, 10.1016/j.foodchem.2012.10.137, 138, 1, 9048-9054, 2013.05.
70. Chihiro Hashimoto, Yuri Iwaihara, Si-Jing Chen, Tanaka Mitsuru, Toshiaki Watanabe, Matsui Toshiro, Highly-Sensitive Detection of Free Advanced Glycation End-Products by Liquid Chromatography-Electrospray Ionization-Tandem Mass Spectrometry with 2,4,6-Trinitrobenzene Sulfonate Derivatization, ANALYTICAL CHEMISTRY, 10.1021/ac400294q, 85, 9, 4289-4295, 2013.05, 生体内での糖化産物である各種AGEを高感度分析する新たなアッセイ法(LC-MS/MS-MRM-TNBS法)を提案した。.
71. Ha-Young Park, Yuri Kunitake, Matsui Toshiro, Benzotropolone moiety in theaflavins is responsible for inhibiting peptide-transport and activating AMP-activated protein kinase in Caco-2 cells., J. Functional Foods in Health and Disease, 3, 5, 111-121, 2013.05.
72. Yuji Miyata, Takashi Tanaka, Kei Tamaya, Toshiro Matsui, Shizuka Tamaru, Kazunari Tanaka, Effects of the firing process on sensory testing and aromatic compounds of a mixed fermented tea product obtained by kneading third-crop green tea and loquat leaves, Nippon Shokuhin Kagaku Kogaku Kaishi, 10.3136/nskkk.60.110, 60, 2, 110-116, 2013, We kneaded third-crop green tea and loquat leaves and prepared them by a firing process in order to manufacture a new fermented tea mix. Sensory testing was carried out and aromatic compounds were measured during the firing stage in order to investigate the effects of temperature and time on the tea product. The firing process did not alter the contents of the major aromatic chemicals in the tea mix. On the other hand, levels of (E,E)-2, 4-heptadienal, an unfavorable aromatic chemical found in low-grade tea leaves, decreased with increases in both temperature and time. Aromatic compounds increased only when firing was carried out at higher temperatures and for longer periods. The firing process does not typically enhance favorable flavors of third-crop teas. However, this study demonstrated that firing can enhance heat-induced aromatic compounds, thereby making it suitable for firstcrop green tea processing..
73. Jennifer Kovacs-Nolan, Hua Zhang, Masahisa Ibuki, Toshihiro Nakamori, Keiko Yoshiura, Patricia V. Turner, Toshiro Matsui, Yoshinori Mine, The PepT1-transportable soy tripeptide VPY reduces intestinal inflammation, Biochimica et Biophysica Acta - General Subjects, 10.1016/j.bbagen.2012.07.007, 1820, 11, 1753-1763, 2012.11, Background: Inflammatory bowel disease (IBD) is a chronic inflammation of the gastrointestinal tract. The peptide transporter PepT1 is responsible for the intestinal uptake of dietary peptides, and its expression in the gastrointestinal tract is up-regulated during intestinal inflammation, indicating that PepT1 may be a promising target for IBD therapeutics. Methods: The transport of soy-derived di- and tripeptides across Caco-2 intestinal epithelial cells was examined, and the anti-inflammatory effects of the transported peptide VPY were evaluated in vitro in Caco-2 and THP-1 macrophages, and in vivo in a mouse model of DSS-induced colitis. Results: VPY inhibited the secretion of IL-8 and TNF-α, respectively, from Caco-2 and THP-1 cells. VPY transport and anti-inflammatory activity in Caco-2 cells was reduced in the presence of Gly-Sar, indicating this activity was mediated by PepT1. In mice, VPY treatment reduced DSS-induced colitis symptoms and weight loss, improved colon histology, reduced MPO activity, and decreased gene expression of the pro-inflammatory cytokines TNF-α, IL-6, IL-1β, IFN-γ and IL-17 in the colon. Conclusions and general significance: VPY is a novel PepT1 substrate that can inhibit the production of pro-inflammatory mediators in vitro in intestinal epithelial and immune cells, and reduce the severity of colitis in mice by down-regulating the expression of pro-inflammatory cytokines in the colon, suggesting that VPY may be promising for the treatment of IBD..
74. Mahmud Tareq Hassan Khan, Kenichi Dedachi, Matsui Toshiro, Noriyuki Kurita, Monica Borgatti, Ingebrigt Sylte, Dipeptide inhibitors of thermolysin and angiotensin I-converting enzyme., Current Topics in Medicinal Chemistry, 12, 16, 1748-1762, 2012.10.
75. Tanaka Mitsuru, Suyama Aki, J. Zhao, Matsui Toshiro, Epigallocatechin gallate enhances the endothelium-independent vasorelaxation of the anti-atherosclerotic Ca2+ channel blocking peptide Trp-His in thoracic aorta from Sprague-Dawley rats, J. Hypertens., eS 1, e279-e279, 2012.09.
76. Toshihiko Fukuda, Yutaro kobayashi, Tanaka Mitsuru, Matsui Toshiro, Vasorelaxant di-peptide, Trp-His, regulates Ca2+-signaling pathway by inhibiting the phosphorylation of voltage-dependent L-type Ca2+ channel in vascular smooth muscle cells, J. Hypertens., eS 1, e279-e279, 2012.09, 血管弛緩ペプチドであるTrp-Hisがラット平滑筋細胞においてカルシウムシグナル系抑制を介してL型カルシウムチャンネルのリン酸化を制御していることを証明した。.
77. Mitsuru Tanaka, Jian Zhao, Aki Suyama, Toshiro Matsui, Epigallocatechin gallate promotes the vasorelaxation power of the antiatherosclerotic dipeptide trp-his in contracted rat aorta, Journal of Agricultural and Food Chemistry, 10.1021/jf3010228, 60, 36, 9048-9054, 2012.09, The aim of this study was to demonstrate the enhancement of the vasorelaxation power of the antiatherosclerotic voltage-dependent L-type Ca 2+ channel (VDCC)-blocking peptide Trp-His by epigallocatechin gallate (EGCg). We found that 300 μM EGCg dramatically enhanced the magnitude of Trp-His-induced vasorelaxation by a factor of >6 (EC50 of Trp-His: EGCg(-), 2.80 ± 0.05 mM; EGCg(+), 0.45 ± 0.04 mM) in phenylephrine-contracted rat aorta. The enhancing effect of EGCg was completely abolished in endothelium-removed aorta and high K+-contracted aorta. The enhancement of Trp-His-induced vasorelaxation by EGCg was significantly diminished by either NG-monomethyl-l-arginine acetate (NO synthase (NOS) inhibitor) or 1-H-[1,2,4]oxadiazolo[4,3]quinoxalin-1-one (soluble guanylyl cyclase inhibitor), together with the enhancement of NOS activity by EGCg. These results indicate that the enhancing effect of EGCg in Trp-His-induced vasorelaxation may be involved in the activation of NO/cGMP pathway..
78. Mitsuru Tanaka, Jian Zhao, Aki Suyama, Matsui Toshiro, Epigallocatechin gallate promotes the vasorelaxation power of the anti-atherosclerotic dipeptide Trp-His in contracted rat aorta, J. Agric. Food Chem, 60, 9048-9054, 2012.08.
79. Ju Qiu, Yuko Kitamura, Yuji Miyata, Shizuka Tamaru, Kazunari Tanaka, Takashi Tanaka, Toshiro Matsui, Transepithelial transport of theasinensins through Caco-2 cell monolayers and their absorption in sprague-dawley rats after oral administration, Journal of Agricultural and Food Chemistry, 10.1021/jf302242n, 60, 32, 8036-8043, 2012.08, The aim of this study is to illustrate the in vivo and in vitro absorption of theasinensins B and A that are (-)-epigallocatechin-3-O-gallate (EGCG)-(-)-epigallocatechin (EGC) dimer and EGCG dimer, respectively, and their transport pathway across the intestinal membrane. Our animal study by a single oral administration to rats demonstrated the intact absorption of theasinensins into the blood system, which was estimated to be a >10-fold lower absorption amount than EGCG. The in vitro absorption study indicated that theasinensins can be transported across Caco-2 cell monolayers, while their permeability coefficients were also >10-fold lower than those of EGCG and EGC. Transport experiments using cytochalasin D or quercetin as a tight junction (TJ) modulator and a non-saturable permeation revealed that theasinensins were transported across Caco-2 cells in a TJ paracellular diffusion route. In conclusion, the dimers of condensed catechins, theasinensins B and A, can be absorbed intact into rat blood and transported across Caco-2 cell monolayers probably through a TJ paracellular pathway..
80. Ju Qiu, Yoko Kitamura, Yuji Miyata, Shizuka Tamaru, Kazunari Tanaka, Takashi Tanaka, Matsui Toshiro, Transepithelial Transport of Theasinensins through Caco-2 Cell Monolayers and Their Absorption in Sprague-Dawley Rats after Oral Administration, J. Agric. Food Chem, 60, 8036-8043, 2012.07.
81. Jennifer Kovacs-Nolan, Hua Zhang, Masahisa Ibuki, Toshihiro Nakamori, Keiko Yoshiura, Patricia V Turner, Matsui Toshiro, Yoshinori Mine, The PepT1-transportable soy tripeptide VPY reduces intestinal inflammation, Biochim. Biophys. Acta-General Subjects, 1820, 1753-1763, 2012.06.
82. Eui-Baek Byun, Teruaki Ishikawa, Aki Suyama, Masaya Kono, Shohei Nakashima, Tomomasa Kanda, Miyamoto Takahisa, Matsui Toshiro, A procyanidin trimer, C1, promotes NO production in rat aortic endothelial cells via both hyperpolarization and PI3K/Akt pathways, Eur. J. Pharm, 10.1016/j.ejphar.2012.07.011, 692, 52-60, 2012.06.
83. S.Tokuda, T.Fukuda, Y.Kobayashi, Mitsuru Tanaka, Matsui Toshiro, Uncharged imidazolium moiety in adenine is responsible for endothelium-independent relaxation in contracted thoracic aorta of Sprague-Dawley rats, Biosci. Biotechnol. Biochem., 76, 4, 828-830, 2012.04.
84. Yutaro Kobayashi, T.Fukuda, Mitsuru Tanaka, Matsui Toshiro, The anti-atherosclerotic di-peptide, Trp-His, inhibits the phosphorylation of voltage-dependent L-type Ca2+ channels in rat vascular smooth muscle cells, FEBS Open Bio, 10.1016/j.fob.2012.04.005, 2, 83-88, 2012.04.
85. Shinji Tokuda, Toshihiko Fukuda, Yutaro Kobayashi, Mitsuru Tanaka, Toshiro Matsui, Effect of the uncharged imidazolium moiety in adenine on endothelium-independent relaxation in the contracted thoracic aorta of sprague-dawley rats, Bioscience, Biotechnology and Biochemistry, 10.1271/bbb.110806, 76, 4, 828-830, 2012.04, Adenine had a concentration-dependent relaxation action on the phenylephrine-contracted aorta ring, with an EC50 value of 0:40 ± 0:12mM. This effect was also observed in the endothelium-denuded aorta. Among the adenine analogues, N-methyladenine and benzimidazole still evoked an apparent relaxation effect, while 1-, 3- or 7-methyladenine and imidazole were no longer vasodilators. These findings demonstrate that the imino group from the uncharged imidazolium moiety in adenine played a key role in the relaxation of the contracted aorta..
86. E.B.Byun, S.Korematsu, T.Ishikawa, T.Nishizuka, S.Ohshima, Matsui Toshiro, Apple procyanidins induce hyperpolarization of rat aorta endothelial cells via activation of K+ channels, J. Nutr. Biochem., 23, 3, 278-286, 2012.03.
87. Eui Baek Byun, Sachiko Korematsu, Teruaki Ishikawa, Taichi Nishizuka, Shunji Ohshima, Tomomasa Kanda, Toshiro Matsui, Apple procyanidins induce hyperpolarization of rat aorta endothelial cells via activation of K + channels, Journal of Nutritional Biochemistry, 10.1016/j.jnutbio.2010.12.005, 23, 3, 278-286, 2012.03, Apple procyanidins (AP), one of the polyphenol-rich compounds, showed an endothelial-dependent vasorelaxation in rat aorta, but the mechanisms of beneficial effects are still unclear. The present study was designed to clarify the potential role of AP in rat aorta endothelial cells (RAECs). The treatment of RAECs with AP (1-10 μg/ml) resulted in a dose-dependent hyperpolarization with a maximum effect at 10 μg/ml, and for this reason, AP (10 μg/ml) was used in all the following experiments. AP-induced hyperpolarization was significantly inhibited by pretreatment of nonspecific K + inhibitor, tetraethyl ammonium chloride or specific K + channel inhibitors, iberiotoxin, glibenclamide, 4-aminopyridine and BaCl 2, as well as by high KCl or Ca 2+-free solution. AP-induced hyperpolarization was also proved using 64-channel multielectrode dish system that can monitor a direct and real-time change of membrane potential. Furthermore, AP treatment caused a significant increase of nitric oxide (NO) production and cyclic guanosine monophosphate levels via endothelial NO synthase messenger RNA expression. The NO production was inhibited by N G-monoethyl-l-arginine or Ca 2+-free solution and was completely abolished by their combination. Also, AP inhibited endothelial proliferation, while the effect was significantly abolished by N G-monoethyl-l-arginine or tetraethyl ammonium chloride. These findings suggest that AP induces both hyperpolarization of RAECs via multiple activation of K + channels and activation of NO/cyclic guanosine monophosphate pathway via increasing NO production or is responsible for antiangiogenic effect. Diminishment of hyperpolarization as well as NO production of AP in Ca 2+-free solution implicated that AP would play a crucial role in promoting Ca 2+ influx into endothelial cells so as to promote both actions..
88. Mahmud Tareq Hassan Khan, Kenichi Dedachi, Toshiro Matsui, Noriyuki Kurita, Monica Borgatti, Roberto Gambari, Ingebrigt Sylte, Dipeptide inhibitors of thermolysin and angiotensin I-converting enzyme, Current Topics in Medicinal Chemistry, 10.2174/156802612803989246, 12, 16, 1748-1762, 2012, Thermolysin (TLN) and other thermolysin-like zinc metalloproteinases (TLPs),are important virulence factors for pathogenesis of bacterial infections by suppressing the innate immune system of the host. Therapeutic inhibition ofTLPs is believed to be a novel strategy inthe development of a new generation antibiotics.In the present study inhibition of TLN and angiotensin I-converting enzyme (ACE) by small peptides were studied by in vitro binding assays and theoretical calculations. The capacity of the peptides to inhibitTLN induced cleavage ofthe transcription factor nuclear factor kappa beta (NF-κB) was studied by electrophoretic mobility shift assays (EMSAs).Nine peptides inhibited ACE with IC50 values in the range 0.48 (IVY) to 1408 (HF) μM, while seven inhibited TLN with IC50 values in the range 0.00034 (IY) to 95640 (FW) μM. Calculations indicated that the peptides occupied the S1' and S2' subsites of ACE, and that IY, LW and IW occupiedthe S1' and S2' subsites, while FW, WL and WV occupiedthe S1 and S1' subsites of TLN. EMSA showed that peptides inhibited TLN induced cleavage of NF-κB. The studied peptides may form as a basis for the design of new compoundstargeting TLN with a potential in the treatment of bacterial infections..
89. Yuji Miyata, Takashi Tanaka, Kei Tamaya, Toshiro Matsui, Shizuka Tamaru and Kazunari Tanaka, Cholesterol-lowering effect of black tea polyphenols, theaflavins, Theasinensin A and thearubigins, in rats fed high fat diet, Food Sci. Technol. Res., 17, 6, 583-588, 2011.12.
90. Takashi Hasegawa, Kiyoshi Matsumoto, Toshiro Matsui, Effect of multistratification and film depth on the visualized dynamic sorption behavior of perylene in cellulose acetate films by a confocal laser scanning microscope technique, Journal of Applied Polymer Science, 10.1002/app.33322, 121, 3, 1780-1787, 2011.08, The sorption behavior of a fluorescent reagent into a polymer film was visualized by confocal laser scanning microscopy (CLSM), and the effects of the additives, film types, and film depth on the diffusion coefficient (D) of the fluorescence reagent were examined. Perylene and cellulose acetate (CA) were used as a fluorescent reagent and a polymer material, respectively. Perylene dissolved in the additives triethylene glycol diacetate (TEGDA) and glycerol triacetate (GTA) was added to the CA film. Then, the evaluation of two types of CA films, a closed-system cellulose acetate (CCA) sample and an open-system cellulose acetate (OCA) sample, was conducted. At optimized CLSM conditions (with a scanning range at a 20-lm depth from the CA film surface with 1-μm intervals and a scanning speed of 1 fps), the sorption of perylene at the inner CA film was determined. The D values of perylene in the CA film were calculated pursuant to Fick's second law. Higher D values of perylene mixed with TEGDA versus those of perylene mixed with GTA were commonly obtained for the CCA sample (TEGDA: 8.9 × 10-15 m 2/s > GTA: 1.7 × 10-15 m2/s) and the OCA sample (TEGDA: 11 × 10-15 m2/s > GTA: 3.3 × 10-15 m 2/s) because of the higher chemical affinity of TEGDA with perylene than that of GTA. Perylene indicated a higher D value and was homogeneously distributed in the case of the OCA sample; we found that diffusivity and distribution of perylene in CA film were largely affected by the multistratification treatment. We also proved that the deeper the film depth was, the lower the diffusivity of perylene was, regardless of the types of additives and films. The factors considered for the film-depth dependence of D were a gradual increase in the diffusion pathway for perylene caused by additive diffusion and the concentration dependence of the perylene D..
91. T.Shii, T.Tanaka, S.Watarumi, Y.Matsuo, Y.Miyata, K.Tamaya, S.Tamaru, K.Tanaka, T.Matsui and I.Kouno, Polyphenol composition of a functional fermented tea obtained by tea-rolling processing of green tea and loquat leaves, J. Agric. Food Chem, 59, 13, 7253-7260, 2011.07.
92. Takuya Shii, Takashi Tanaka, Sayaka Watarumi, Yosuke Matsuo, Yuji Miyata, Kei Tamaya, Shizuka Tamaru, Kazunari Tanaka, Toshiro Matsui, Isao Kouno, Polyphenol composition of a functional fermented tea obtained by tea-rolling processing of green tea and loquat leaves, Journal of Agricultural and Food Chemistry, 10.1021/jf201499n, 59, 13, 7253-7260, 2011.07, Phenolic constituents of a new functional fermented tea produced by tea-rolling processing of a mixture (9:1) of tea leaves and loquat leaves were examined in detail. The similarity of the phenolic composition to that of black tea was indicated by high-performance liquid chromatography comparison with other tea products. Twenty-five compounds, including three new catechin oxidation products, were isolated, and the structures of the new compounds were determined to be (2R)-2-hydroxy-3-(2,4,6-trihydroxyphenyl)-1-(3,4,5- trihydroxyphenyl)-1-propanone 2-O-gallate, dehydrotheasinensin H, and acetonyl theacitrin A by spectroscopic methods. In addition, theacitrinin A and theasinensin H were obtained for the first time from commercial tea products. Isolation of these new and known compounds confirms that reactions previously demonstrated by in vitro model experiments actually occur when fresh tea leaves are mechanically distorted and bruised during the production process..
93. Ju Qiu, Nozomi Saito, Mai Noguchi, Keiichi Fukui, Kayo Yoshiyama, Kazusato Matsugano, Norihiko Terehara, Toshiro Matsui, Absorption of 6- O -caffeoylsophorose and its metabolites in sprague-dawley rats detected by electrochemical detector-high-performance liquid chromatography and electrospray ionization-time-of-flight-mass spectrometry methods, Journal of Agricultural and Food Chemistry, 10.1021/jf200764d, 59, 11, 6299-6304, 2011.06, Absorption and metabolism of a natural compound, 6-O-caffeoylsophorose (CS) from acylated anthocyanins in a red vinegar fermented with purple sweetpotato, were clarified. The absorption of CS and conjugated CS in blood from orally administrated Sprague-Dawley rats at a dose of 400 mg/kg was investigated by electrochemical detection-high performance liquid chromatography. As a result, CS was successfully detected in rat plasma (AUC0-6h, 108.6 ± 8.1 nmol h/mL) and was found to be an intact absorbable polyphenol. In addition, half of the absorbed CS was detected as its conjugates (AUC0-6h, 50.7 ± 5.7 nmol h/mL) as well as caffeic and ferulic acids from CS. By a time-of-flight-mass spectrometric analysis of CS-administered plasma sample, glucuronide and methylated conjugates of CS were identified, in addition to glucuronide, methylated, or sulfate conjugates of caffeic and ferulic acids. Consequently, CS was absorbed in intact form into rat blood and partly degraded to caffeic and ferulic acids or metabolized by glucuronidation, methylation, or sulfatation..
94. J.Qiu, N.Saito, M.Noguchi, K.Fukui, K.Yoshiyama, K.Matsugano, N.Terahara and T.Matsui, Absorption of 6-O-caffeoylsophorose and its metabolites in Sprague-Dawley rats detected by ECD-HPLC and ESI-TOF-MS methods, J. Agric. Food Chem., 59, 11, 6299-6304, 2011.05.
95. Jae Sung Hwang, Hyung Jae Yoo, Hye Jung Song, Kyu Kwang Kim, Young Jin Chun, Toshiro Matsui, Han Bok Kim, Inflammation-related signaling pathways implicating TGFβ are revealed in the expression profiling of MCF7 cell treated with fermented soybean, Chungkookjang, Nutrition and Cancer, 10.1080/01635581.2011.551987, 63, 4, 645-652, 2011.05, Chungkookjang is a Korean fermented soybean containing microorganisms, proteinase, and diverse bioactive compounds, including a high concentration of isoflavones and peptides. Growth of breast cancer MCF7 cells decreased dependent on the concentration of fermented soybean extracts. The effect of fermented soybean on cellular gene expression was determined in a systematic manner comprehensively. DNA microarray analysis was performed using 25,804 probes. Ninety one genes whose expression levels were significantly changed were selected. TGFβI and Smad3 were upregulated. Downregulation of inflammation-related CSF2, CSF2RA, and CSF3 was found. Differential expression of chemokines CCL2, CCL3, CCL3L3, CXCL1, and CXCL2 were observed. Network analysis identified ERβ in the network. Based on the experimental results, taking fermented soybean might be helpful for preventing breast cancer by a mechanism activating TGFβ pathway and depressing inflammation.[Supplemental materials are available for this article. Go to the publisher's online edition of Nutrition and Cancer for the following free supplemental resources: Detailed table showing the full list of genes and their analysis details.].
96. E. M. N. Nakashima, A.Kudo, Y. Iwaihara, M. Tanaka, K. Matsumoto, T. Matsui, Application of 13C-stable-isotope labeling LC-MRM-MS/MS method for determining intact absorption of bioactive di-peptides in rats., Anal. Biochem., 10.1016/j.ab.2011.02.037, 414, 4, 109-116, 2011.04.
97. Jae Sung Hwang, Hyung Jae Yoo, Hye Jung Song, Kyu Kwang Kim, Young Jin Chun, Toshiro Matsui, Han Bok Kim, Inflammation-related signaling pathways implicating TGFβ are revealed in the expression of profiling of MCF7 cell treated with fermented soybean, Chungkookjang, Nutrition and Cancer, 63, 4, 645-652, 2011.04.
98. N. Inoue, K. Nagao, K.Sakata, N.Yamano, P.E.R.Gunawardena, S.Y.Han, T.Matsui, T.Nakamori, H.Furuta, K.Takamatsu and T.Yanagita, Screening of soy protein-derived hypotriglyceridemic di-peptides in vitro and in vivo, Lipids in Health and Disease, 10, 85-94, 2011.04.
99. T.Hasegawa, T.Matsui, K.Matsumoto, Effect of multi stratification and film depth on visualized dynamic sorption behavior of perylene in cellulose acetate film by confocal laser scanning microscope technique., J.Appl.Polymer Sci., 121, 3, 1780-1787, 2011.03.
100. Nguyen Thi Thu Hang, Ikuo Miyajima, Kenji Ureshino, Nobuo Kobayashi, Yuji Kurashige, Toshiro Matsui, Hiroshi Okubo, Anthocyanins of wild Rhododendron simsii Plant. flowers in Vietnam and Japan, J. Japan Soc. Hor. Sci., 80, 2, 206-213, 2011.02.
101. Toshiro Matsui, Zhengquan Wang, Mitsuru Tanaka, Vascular regulation by small peptides, Bioactive Natural Products: Opportunities and Challenges in Medicinal Chemistry, 10.1142/9789814335386_0002, 201-221, 2011.01, Several peptides possessing antihypertensive effect proved to play a promising role in regulating vascular functions as described in the past researches. The present chapter is aimed to offer an overview of a new functionality of small peptides in preventing hypertension and vessel dysfunctions including atherosclerosis..
102. Nguyen Thi Thu Hang, Ikuo Miyajima, Kenji Ureshino, Nobuo Kobayashi, Yuji Kurashige, Toshiro Matsui, Hiroshi Okubo, Anthocyanins of wild Rhododendron simsii planch. Flowers in Vietnam and Japan, Horticulture Journal, 80, 2, 206-213, 2011, Fourteen anthocyanins were detected in the flowers of R. simsii distributed in Vietnam and Japan. The anthocyanin constituents of R. simsii flowers seem to be more complex in the Japanese than Vietnamese population. The percentage of each flower anthocyanin was very low except for two major anthocyanins found in all Vietnamese and Japanese accessions. It was not possible to classify the Vietnamese and Japanese populations by flower anthocyanin constituents. The two major anthocyanins found in all accessions of R. simsii flowers in Vietnam and Japan were isolated and purified by column and high-performance liquid chromatography. Their structures were elucidated by 1H-NMR spectroscopic analyses and either acid or alkaline hydrolysis, and they were identified as cyanidin 3-galactoside and cyanidin 3-arabinoside. These two anthocyanins seem to be common to red-flowered evergreen azaleas, such as R. indicum, R. kaempferi, R. oldhamii, and R. scabrum. JSHS.
103. Yuji Miyata, Takashi Tanaka, Kei Tamaya, Toshiro Matsui, Shizuka Tamaru, Kazunari Tanaka, Cholesterol-lowering effect of black tea polyphenols, theaflavins, theasinensin a and thearubigins, in rats fed high fat diet, Food Science and Technology Research, 10.3136/fstr.17.585, 17, 6, 585-588, 2011, Rats were fed a high fat diet containing 0.2% black tea polyphenols, theaflavins, theasinensin A or thearubigins for 4 weeks. The hepatic cholesterol concentration was significantly lower in rats fed the theaflavins, theasinensin A or thearubigins diet than in those fed the control diet without black tea polyphenols. Theasinensin A and thearubigins significantly accelerated fecal neutral and acidic steroid excretion, respectively. These results suggest that theasinensin A and thearubigins might induce the hepatic cholesterol-lowering activity through the promotion of fecal steroid excretion..
104. Taro Sano, Shinjiro Kagawa, Toshiro Matsui, Prediction of sorption of isomeric flavors with solubility parameters, Journal of Packaging Science and Technology, 20, 3, 189-195, 2011, It is well-known that the sorption of flavors into plastic packagings seriously causes deterioration of food quality. In a series of our studies regarding sorption behavior of flavors we have successfully proposed a thermodynamic sorption equation to predict sorption behavior of flavors into plastic films on the basis of their Solubility Parameter (SP value). However, the application of the equation or SP values was restrictive to flavors without isomeric conformation, since SP values of isomers that are calculated by the sum of their cohesive energy density of atomic groups can not be distinguishable among isomers. In this study, thus, we have attempted to propose a new method to predict sorption behavior of flavor isomers using a contact angle method. Namely, using the calibration curve of flavors having known SP values with contact angle, SP values of isomers were successfully estimated. A good correlation between sorption behavior of isomers into plastic film and the sorption equation that their SP values were applied was observed, which indicated that the proposed SP estimation method using contact angle is applicable for predicting sorption of flavor isomers..
105. Nao Inoue, Koji Nagao, Kotaro Sakata, Naomi Yamano, Pathma Elgoda Ranawakage Gunawardena, Seo Young Han, Toshiro Matsui, Toshihiro Nakamori, Hitoshi Furuta, Kiyoharu Takamatsu, Teruyoshi Yanagita, Screening of soy protein-derived hypotriglyceridemic di-peptides in vitro and in vivo, Lipids in Health and Disease, 10.1186/1476-511X-10-85, 10, 2011, Background: Soy protein and soy peptides have attracted considerable attention because of their potentially beneficial biological properties, including antihypertensive, anticarcinogenic, and hypolipidemic effects. Although soy protein isolate contains several bioactive peptides that have distinct physiological activities in lipid metabolism, it is not clear which peptide sequences are responsible for the triglyceride (TG)-lowering effects. In the present study, we investigated the effects of soy protein-derived peptides on lipid metabolism, especially TG metabolism, in HepG2 cells and obese Otsuka Long-Evans Tokushima fatty (OLETF) rats. Results: In the first experiment, we found that soy crude peptide (SCP)-LD3, which was prepared by hydrolyze of soy protein isolate with endo-type protease, showed hypolipidemic effects in HepG2 cells and OLETF rats. In the second experiment, we found that hydrophilic fraction, separated from SCP-LD3 with hydrophobic synthetic absorbent, revealed lipid-lowering effects in HepG2 cells and OLETF rats. In the third experiment, we found that Fraction-C (Frc-C) peptides, fractionated from hydrophilic peptides by gel permeation chromatography-high performance liquid chromatography, significantly reduced TG synthesis and apolipoprotein B (apoB) secretion in HepG2 cells. In the fourth experiment, we found that the fraction with 0.1% trifluoroacetic acid, isolated from Frc-C peptides by octadecylsilyl column chromatography, showed hypolipidemic effects in HepG2 cells. In the final experiment, we found that 3 di-peptides, Lys-Ala, Val-Lys, and Ser-Tyr, reduced TG synthesis, and Ser-Tyr additionally reduced apoB secretion in HepG2 cells. Conclusion: Novel active peptides with TG-lowering effects from soy protein have been isolated..
106. Yuji Miyata, Takashi Tanaka, Kei Tamaya, Toshiro Matsui, Shizuka Tamaru, Kazunari Tanaka, Technological development of a simple and rapid method of producing fermented teas using di erent kinds of tea leaves, and the manufacturing of new types of mixed fermented teas, Nippon Shokuhin Kagaku Kogaku Kaishi, 10.3136/nskkk.58.403, 58, 9, 403-412, 2011, The third crop of green tea leaves contains a relatively large amount of catechins, resulting in a bitter taste to the hot-water extract of its leaves. On the other hand, loquat leaves have a strong enzymatic activity that can oxidize catechins. They also contain chlorogenic acid, which accelerates the oxidation of catechins. Thus, we tried to promote the oxidative polymerization of catechins in third-crop green tea leaves by the addition of loquat leaves, and presumed that the taste of the third-crop green tea would be improved. However, the active ingredients contained in loquat leaves are difficult to extract with hot water due to the hardness of the leaves. Thus, we mixed and kneaded the third-crop green tea leaves and loquat leaves together using the tea roller of a tea manufacturing machine, which may have facilitated the elution of the components contained in loquat leaves, and may have effectively promoted the oxidation of catechins contained in the third-crop green tea. In this study, we improved the conventional method of producing black tea leaves, and developed a method for producing new high-quality mixed and fermented tea using the third crop of green tea leaves and loquat leaves, which were previously unused resources. We outline our main eforts here..
107. Zhengquan Wang, Shimpei Watanabe, Yutaro Kobayashi, Mitsuru Tanaka, Toshiro Matsui, Trp-His, a vasorelaxant di-peptide, can inhibit extracellular Ca 2+ entry to rat vascular smooth muscle cells through blockade of dihydropyridine-like l-type Ca2+ channels, Peptides, 10.1016/j.peptides.2010.07.013, 31, 11, 2060-2066, 2010.11, Our previous findings regarding the biological activities of small peptides revealed that a di-peptide, Trp-His (WH), could play a role in the prevention of vascular lesions, including cell proliferation and atherosclerosis. Its vasoprotective effects could be associated with suppression of the vasocontraction signaling cascade, but the underlying mechanism(s) remains obscure. In this study, we attempted to elucidate the vasoprotective mechanism of WH, in opposing the proliferation of rat vascular smooth muscle cells (VSMCs). In VSMCs from 8 week-old male Wistar rat thoracic aortae, WH evoked a significant dose-dependent anti-proliferation effect, without cytotoxicity. In mitogen-stimulated cell experiments, 300 μM WH inhibited cytosolic Ca 2+ elevation in VSMCs induced by 10 μM angiotensin II (Ang II). Furthermore, WH suppressed extracellular Ca2+ entry into CaCl 2-stimulated VSMCs. The biological capacity of WH as an intracellular Ca2+ ([Ca2+]i) suppressor was also proven when 50 μM Bay K8644 was used to enhance Ca2+ entry via a voltage-dependent l-type Ca2+ channel (VDCC) and 300 μM WH elicited a 23% reduction in [Ca2+]i. The absence of a reduction of the [Ca2+]i by the mixture of tryptophan and histidine revealed the importance of the peptide backbone in the [Ca 2+]i reduction effect. Furthermore, the WH-induced [Ca2+]i reduction was abolished by verapamil, but not by nifedipine, indicating that WH likely binds to an extracellular site of the VDCC at a site similar to that of the dihydropyridine type-Ca2+ channel blockers..
108. Z.Wang, S.Watanabe, Y.Kobayashi, M.Tanaka, T.Matsui, Trp-His, a vasorelaxant di-peptide, can inhibit extracellular Ca2+ entry to rat vascular smooth muscle cells through blockade of dihydropyridine-like L-type Ca2+ channels, Peptides, 31, 2060-2066, 2010.10, 抗動脈硬化作用並びに血管弛緩作用を有するジペプチドTrp-Hisが血管平滑筋細胞膜に局在する電位依存性L型カルシウムチャンネルに結合し、降圧薬であるニフェジピンと同様に細胞内へのカルシウムイオンの流入を遮断させることを明らかにした。.
109. T.Matsui, A.Kudo, S.Tokuda, K.Matsumoto, H.Hosoyama, Identification of a new natural vasorelaxatant compound, (+)-osbeckic acid, from rutin-free tartary buckwheat extract, J. Agric. Food Chem., 58, 20, 10876-10879, 2010.10.
110. Toshiro Matsui, Akihiro Kudo, Shinji Tokuda, Kiyoshi Matsumoto, Hirokazu Hosoyama, Identification of a new natural vasorelaxatant compound, (+)-osbeckic acid, from rutin-free tartary buckwheat extract, Journal of Agricultural and Food Chemistry, 10.1021/jf1028416, 58, 20, 10876-10879, 2010.10, The candidates responsible for vasorelaxation action of rutin-free tartary buckwheat extract (TBSP) were examined in this study. As a result of reversed-phase high-performance liquid chromatography (HPLC) separations, five prominent peaks in the acidic fraction of TBSP were obtained at 260 nm. Among the five collected peaks, we successfully identified four compounds by nuclear magnetic resonance (NMR) and mass spectrometry (MS) measurements: (+)-osbeckic acid as a dimer ([M - H]- m/z: 371.2 > 184.9 > 140.9), 5-hydroxymethyl-2-furoic acid, protocatechuic acid, and p-hydroxybenzoic acid. A vascular contractive measurement in 1.0 μM phenylephrine-contracted Sprague-Dawley rat thoracic aorta rings revealed that (+)-osbeckic acid dimer evoked a potent vasorelaxant effect with an EC50 value of 887 μM compared to other isolates (EC50: 5-hydroxymethyl-2-furoic acid, 3610 μM; protocatechuic acid, 2160 μM; p-hydroxybenzoic acid, no inhibition). Dimeric (+)-osbeckic acid was stable in solutions and at high temperatures, while its degraded peak on the HPLC chromatogram was observed when it was dissolved in dimethyl sulfoxide..
111. K.Tanaka, S.Tamaru, S.Nishizono, Y.Miyata, K.Tamaya, T.Matsui, T.Tanaka, Y.Echizen, I.Ikeda, Hypotriacylglycerolemic and antiobesity properties of a new fermented tea product obtained by tea-rolling processing of third-crop green tea (Camellia sinensis) leaves and loquat (Eriobotrya japonica) leaves, Biosci. Biotechnol. Biochem., 74, 8, 1606-1612, 2010.08.
112. Asami Toshima, Toshiro Matsui, Mai Noguchi, Ju Qiu, Kei Tamaya, Yuji Miyata, Takashi Tanaka, Kazunari Tanaka, Identification of α-glucosidase inhibitors from a new fermented tea obtained by tea-rolling processing of loquat (Eriobotrya japonica) and green tea leaves, Journal of the Science of Food and Agriculture, 10.1002/jsfa.3983, 90, 9, 1545-1550, 2010.07, Background: A new fermented tea produced by tea-rolling processing of loquat (Eriobotrya japonica) leaf with green tea leaf (denoted as LG tea) showed a potent antihyperglycaemic effect in maltose-loaded rats. The aim of this study, therefore, was to identify α-glucosidase inhibitors in the antihyperglycaemic tea product. Results: LG tea had a threefold higher maltase-inhibitory activity (IC50 0.065 mgdried extractm L-1) than either the constituent loquat leaf or green tea alone. In addition, LG tea favourably inhibited maltase action rather than sucrase action. As a result of bioguided high-performance liquid chromatography separations of LG tea, theasinensin A, theasinensin B, strictinin and 1,6-digalloylglucose were newly identified asmaltase inhibitors with IC50 values of 142, 225, 398 and 337 μmol L-1 respectively, along with previously identified catechins and theaflavins. Conclusion: Judging from the magnitude of the α-glucosidase-inhibitory contribution of each isolated compound to the overall inhibition of LG tea, catechins were the main candidates responsible for α-glucosidase or maltase inhibition in LG tea, followed by theaflavins, theasinensins, strictinin and 1,6-digalloylglucose..
113. E.B.Byun, N.Y.Sung, J.H.Kim, J.Choi, T.Matsui, M.W.Byun, J.W.Lee, Enhancement of anti-tumor activity of gamma-irradiated silk fibroin via immunomodulatory effects, Chemico-Biological Interactions, 186, 90-95, 2010.06.
114. Toshiro Matsui, Mitsuru Tanaka, Antihypertensive Peptides and Their Underlying Mechanisms, Bioactive Proteins and Peptides as Functional Foods and Nutraceuticals, 10.1002/9780813811048.ch4, 43-54, 2010.06.
115. Eui Baek Byun, Nak Yun Sung, Jae Hun Kim, Jong il Choi, Toshiro Matsui, Myung Woo Byun, Ju Woon Lee, Enhancement of anti-tumor activity of gamma-irradiated silk fibroin via immunomodulatory effects, Chemico-Biological Interactions, 10.1016/j.cbi.2010.03.032, 186, 1, 90-95, 2010.06, Silk fibers have proven to be effective in many clinical applications as well as for clothing. In addition to the substantial effect of silk fibers, the present study was conducted to explore its importance in a new dimension to reinforce the effects of its physiological function regarding anti-tumor activity and immune response with gamma-irradiated silk fibroin (GISF). The cytotoxicity results showed that pre-treatment of GISF in the mouse peritoneal macrophages (MPM) indicated a higher proliferative effect than that of non-irradiated silk fibroin (NISF) in a concentration-dependent manner. Based on the cytotoxicity result of MPM, GISF (50 and 150. kGy) was selected for an ex vivo study in an animal (C57BL6) system and evaluated about whether the non-specific immune response was also related to GISF. GISF (50 and 150. kGy) augmented immune responsiveness via activation of NK cells, T lymphocytes proliferation, NO production, and cytokine level, such as IL-6, IL-2, IL-12, IFN-γ, TNF-α, as compared with NISF, which strongly suggested that GISF significantly augmented an important element of all aspects of the innate and adaptive immune system. Therefore, from these results, it seems likely that the GISF will play a potent role in eliciting the effect of the non-specific immune response and anti-tumor activity as a value-added product in the medical industry..
116. T.Hasegawa, T.Matsui, K.Matsumoto, Application of confocal laser scanning microscope technique to visualize dynamic sorption behavior of perylene in cellulose acetate film, J. Appl. Polymer Sci., 116, 5, 1552-1557, 2010.05.
117. T.Hasegawa, T.Matsui, K.Matsumoto, Comparative study of additives on visualized dynamic sorption behavior of perylene in cellucose acetate film by confocal laser scanning microscope technique, J. Appl. Polymer Sci., 116, 5, 1710-1717, 2010.05.
118. A.Toshima, T.Matsui, M.Noguchi, J.Qiu, K.Tamaya, Y.Miyata, T.Tanaka, K.Tanaka, Identification of α-glucosidase inhibitors from a new fermented tea obtained by tea-rolling processing of loquat (Eriobotrya japonica) and green tea leaves, J. Sci. Food Agr., 90, 1545-1550, 2010.05.
119. Toshiro Matsui, Xiao Lin Zhu, Koso Shiraishi, Tatsuro Ueki, Yoshiharu Noda, Kiyoshi Matsumoto, Antihypertensive effect of salt-free soy sauce, a new fermented seasoning, in spontaneously hypertensive rats, Journal of Food Science, 10.1111/j.1750-3841.2010.01599.x, 75, 4, 2010.05, In this study, we focused on the antihypertensive effect of newly fermented salt-free soy sauce (SFS) in spontaneously hypertensive rats (SHRs). A 13-wk oral administration of SFS was performed daily in 8- to 21-wk-old SHRs with a dose of 200 mg/kg of body weight/d. The systolic (SBP) and diastolic (DBP) blood pressures were measured for each week during the experimental period. As a result, a significant (P < 0.01) BP lowering effect was observed from the 5th d to the end of the experiment in the SFS group compared with the control group (ΔSBP21-wk: 27 mmHg, ΔDBP21-wk: 20 mmHg). In contrast to such substantial effect by SFS intake, angiotensin I-converting enzyme activities in blood and local organs as well as pharmaceutical parameters such as serum Na+ or K+ level did not show any significant difference between in both SFS and control groups. Vasoconstriction experiment using thoracic aorta rings from 21-wk SHRs provided an interesting result that the rings from the SFS group evoked a >2-fold higher increase in the angiotensin II-stimulated constrictive response compared with the rings from the control group (P = 0.012), which suggested that the SFS-intake would be effective in possessing a higher vessel tone.Practical Application: In this study, we investigated the antihypertensive effect of newly fermented SFS in SHRs. As a result of 13-wk SFS-administration, we found a significant antihypertensive effect of the SFS. This finding strongly demonstrates that the developed SFS would be greatly beneficial for health and useful for health-related industries..
120. Takashi Hasegawa, Toshiro Matsui, Kiyoshi Matsumoto, Application of confocal laser scanning microscope technique to visualize dynamic sorption behavior of perylene in cellulose acetate film, Journal of Applied Polymer Science, 10.1002/app.31392, 116, 3, 1552-1557, 2010.05, Additives distributed in a polymer film were visualized by a confocal laser scanning microscope (CLSM) in this study. Cellulose acetate (CA) was used as the polymer film material. Perylene as a fluorescence reagent and glycerol triacetate (GTA) as a plasticizer for CA, respectively, were selected and mixed for visualizing the absorption of perylene into CA. Under optimized CLSM conditions of an objective lens (dry, 20×) and diode laser (408 nm, 290-330 μW), a fluorescent penetrant, perylene, in GTA solution was detected in CA casting film within around 9 μm depth of the film in 60 minutes after starting the sorption study. It was also found that the fluorescence intensity of perylene became lower with the film depth. This finding suggested that CLSM could visualize the sorption behavior of perylene as a dynamic diffusion process. Analytical conditions, such as a scanning range along the Z axis (±10 or ±30 μm from an air-contact surface of the CA film) and a scan speed (1 or 30 fps) of CLSM, did not affect the fluorescence intensity of the sorbed perylene. It was concluded that a newly developed analytical methodology using CLSM was sufficient for visualizing the perylene penetrant across the cross-sectional distribution of the CA film, being capable of monitoring the sorption behavior of compounds in polymer materials without any destruction of a given absorbed film..
121. Takashi Hasegawa, Toshiro Matsui, Kiyoshi Matsumoto, Comparative study of additives on visualized dynamic sorption behavior of perylene in cellulose acetate film by confocal laser scanning microscope technique, Journal of Applied Polymer Science, 10.1002/app.31607, 116, 3, 1710-1717, 2010.05, The sorption behavior of a fluorescent reagent into a polymer film was visualized by confocal laser scanning microscope (CLSM), and the effect of additives on the sorption was examined. Perylene and cellulose acetate (CA) were used as a fluorescent reagent and a polymer material, respectively. Perylene dissolved in additives of glyc-erol triacetate (GTA), triethylene glycol diacetate (TEGDA), 1,3-butylene glycol diacetate (BGDA), paraffin liquid, and poly(ethylene glycol) 200 (PEG) were added onto CA film. At optimized CLSM conditions (scanning range of a 10 lm-depth from the CA film surface with 1 lm intervals and a scanning speed of 1 fps), the sorption of perylene at the inner CA film was determined. Diffusion coefficients of perylene in the CA film were calculated according to Fick's second law. When perylene was dissolved in TEGDA, the highest diffusion coefficient, 8.9 × 10-15 m 2/s, among the additives was obtained because of high affinity of TEGDA with perylene, whereas the lowest diffusion coefficient was observed in paraffin liquid, which showed a low affinity with perylene. The diffusion coefficients of perylene in GTA, BGDA, and PEG also revealed that physical parameters, such as molecular size and viscosity, of the additives were additional factors affecting the perylene diffusivity in the CA film..
122. T.Matsui, X.L.Zhu, K.Shiraishi, T.Ueki, Y.Noda, K.Matsumoto, Antihypertensive effect of salt-free soy sauce, a new fermented seasoning, in spontaneously hypertensive rats, J.Food Sci., 75, 4, H129-H134, 2010.04.
123. Kei Tamaya, Toshiro Matsui, Asami Toshima, Mai Noguchi, Qiu Ju, Yuji Miyata, Takashi Tanaka, Kazunari Tanaka, Suppression of blood glucose level by a new fermented tea obtained by tea-rolling processing of loquat (Eriobotrya japonica) and green tea leaves in disaccharide-loaded Sprague-Dawley rats, Journal of the Science of Food and Agriculture, 10.1002/jsfa.3883, 90, 5, 779-783, 2010.04, Background: In the field of food science, much interest has been focused on the development of alternative medicinal foods with the ability to regulate excess blood glucose level (BGL) rise. The authors have successfully developed a new fermented tea product (LG tea) by co-fermentation of loquat (Eriobotrya japonica) leaf and summer-harvested green tea leaf. The objective of this study was to examine the acute suppression effect of LG tea on BGL rise in disaccharide-loaded Sprague-Dawley (SD) rats and to evaluate its possible usage as an antidiabetic functional food material. Results: As a result of single oral administration of hot water extract of LG tea (50 mg kg-1) to maltose-loaded SD rats, BGL at 30 min was significantly decreased by 23.8% (P < 0.01) compared with the control. A corresponding reduction in serum insulin secretion was also observed. The ED50 value of LG tea (50.7 mg kg-1) was estimated to be about 16-fold higher than that of the therapeutic drug acarbose (3.1 mg kg-1). Conclusion: No significant change in BGL was observed when sucrose or glucose was administered, suggesting that the suppression effect of LG tea was achieved by maltase inhibition, not by sucrase inhibition or glucose transport inhibition at the intestinal membrane..
124. T.Matsui, M.Sato, M.Tanaka, Y.Yamada, S.Watanabe, Y.Fujimoto, K.Imaizumi, K.Matsumoto, Vasodilating di-peptide Trp-His can prevent atherosclerosis in apolipoprotein E-deficient mice, Br. J. Nutr., 103, 3, 309-313, 2010.03.
125. K.Tamaya, T.Matsui, A.Toshima, M.Noguchi, J.Qiu, Y.Miyata, T.Tanaka, K.Tanaka, Suppression of blood glucose level by a new fermented tea obtained by tea-rolling processing of loquat (Eriobotrya japonica) and green tea leaves in disaccharides-loaded Sprague-Dawley rats, J. Sci. Food Agr., 90, 779-783, 2010.03.
126. Roman Selyanchyn, Serhiy Korposh, Toshiro Matsui, Hidetaka Matsui, Seung Woo Lee, Purge and trap sampling coupled to curie point thermal desorption for the detection of parts per trillion 2,4,6-trichloroanisole in water, Chromatographia, 10.1365/s10337-009-1428-x, 71, 3-4, 317-321, 2010.02, GC-MS analysis based on purge and trap sampling followed by Curie point thermal desorption was examined for the quantitative determination of 2,4,6-trichloroanisole in aqueous solutions. The method developed showed linearity in single ion monitoring mode over a TCA concentration range of 0.12-120 ng L-1 (parts-per-trillion)..
127. Toshiro Matsui, Masao Sato, Mitsuru Tanaka, Yasuna Yamada, Shimpei Watanabe, Yumiko Fujimoto, Katsumi Imaizumi, Kiyoshi Matsumoto, Vasodilating dipeptide Trp-His can prevent atherosclerosis in apo E-deficient mice, British Journal of Nutrition, 10.1017/S0007114509991814, 103, 3, 309-313, 2010.02, Most of the investigations for an alternative medicinal treatment on atherosclerosis have been focused on natural or dietary compounds including phytochemicals. So far, few studies regarding anti-atherosclerotic small peptides except for tetrapeptide of Lys-Arg-Glu-Ser have been reported. The present study was, thus, to investigate whether dipeptide Trp-His, which is one of vasodilating small peptides, could reduce atherosclerotic lesions in apo E-deficient mice fed a high-fat diet. The animal study involved a 9-week-successive administration of Trp-His at a dose of 0, 10 or 100mg/kg per d. After 9-week administration, en face analyses provided the first direct evidence that the atherosclerotic lesion area was significantly reduced by 27 and 38% for Trp-His dosed at 10 and 100mg/kg per d, respectively, compared with the control group. Administration of Trp-His did not affect growth parameters such as body weight and feeding efficiency (P>01). Total serum cholesterol and HDL-cholesterol as well as lipid profiles in the liver did not differ between the tested groups. Taken together, the anti-atherosclerotic effect of dipeptide Trp-His should be addressed into physiological functions of bioactive peptides, in which the dipeptide may elicit the power by alternative mechanism(s), not by the regulation of lipid metabolism..
128. R.Selyanchyn, S.Korposh, T.Matsui, H.Matsui, S.W.Lee, Purge and trap sampling coupled to curie point thermal desorption for the detection of parts per trillion 2,4,6-trichloroanisole in water, Chromatographia, 71, 317-321, 2010.01.
129. Yuji Miyata, Takashi Tanaka, Masayuki Noda, Kei Tamaya, Toshiro Matsui, Shoko Nishizono, Shizuka Tamaru, Kazunari Tanaka, Characteristics of aroma compounds in mixed fermented tea containing green tea and loquat leaves, Nippon Shokuhin Kagaku Kogaku Kaishi, 10.3136/nskkk.57.171, 57, 4, 171-174, 2010, To clarify the aroma characteristics of fermented tea manufactured by mixed kneading of the third crop of green tea leaves and loquat leaves (mixed fermented tea), we measured the aroma components by gas chromatography/mass spectroscopy. (Z)-3-hexen-l-ol acetate, which was not a component found in green or loquat tea, was detected in the mixed fermented tea. Geraniol was the most abundant aroma component in the mixed fermented tea. A relatively large amount of benzaldehyde, benzylalcohol and nerolidol was detected in the mixed fermented tea compared to that in black, green and loquat teas. These results suggest that the aroma components of the mixed fermented tea were produced during fermentation after the mixture of green tea and loquat leaves..
130. Kazunari Tanaka, Shizuka Tamaru, Shoko NishizonO, Yuji Miyata, Kei Tamaya, Toshiro Matsui, Takashi Tanaka, Yoshie EChizen, Ikuo Ikeda, Hypotriacylglycerolemic and antiobesity properties of a new fermented tea product obtained by tea-rolling processingof third-crop green tea (Camellia sinensis) leaves and loquat (Eriobotrya japonica) Leaves, Bioscience, Biotechnology and Biochemistry, 10.1271/bbb.100197, 74, 8, 1606-1612, 2010, We manufactured a new fermented tea by tea-rolling processing of third-crop green tea (Camellia sinensis) leaves and loquat (Eriobotrya japonica) leaves. The mixed fermented tea extract inhibited pancreatic lipase activity in vitro, and effectively suppressed postprandial hypertriacylglycerolemia in rats. Rats fed a diet containing1% freeze-dried fermented tea extract for 4 weeks had a significantly lower liver triacylglycerol concentration and white adipose tissue weight than those fed the control diet lacking fermented tea extract. The activity of fatty acid synthase in hepatic cytosol markedly decreased in the fermented tea extract group as compared to the control group. The serum and liver triacylglycerol- and body fat-lowering effects of the mixed fermented tea extract were strong relative to the level of dietary supplementation. These results suggest that the new fermented tea product exhibited hypotriacylglycerolemic and antiobesity properties through suppression of both liver fatty acid synthesis and postprandial hypertriacylglycerolemia by inhibition of pancreatic lipase..
131. Toshiro Matsui, Sachiko Korematsu, Eui-Baek Byun, Taichi Nishizuka, Shunji Ohshima and Tomomasa Kanda, Apple Procyanidins Induce Vascular Relaxation in Isolated Rat Aorta through NO/cGMP Pathway in Combination with Hyperpolarization by Multiple K+ Channel Activations, Biosci. Biotechnol. Biochem., 73(10), 2246-2251, 2009.10.
132. Norihiko Terahara, Toshiro Matsui,Kanako Minoda, Kanae Nasu, Risa Kikuchi, Keiichi Fukui, Hiroshi Ono, and Kiyoshi Matsumoto, Functional new acylated sohoroses and deglucosylated anthocyanins in a fermented red vinegar, J. Agric. Food Chem, 57(18), 8331-8338 , 2009.10.
133. Takashi Tanaka, Yuji Miyata, Kei Tamaya, Rie Kusano, Yusuke Matsuo, Shizuka Tamaru, Kazunari Tanaka, Toshiro Matsui, Masamichi Maeda, Isao Kouno, Increase of theaflavin gallates and thearubigins by acceleration of catechin oxidation in a new fermented tea product obtained by tea-rolling processing of loquat (Eriobotrya japonica) and green tea leaves, J. Agric. Food Chem., 57(13), 5816-5822, 2009.09.
134. Norihiko Terahara, Toshiro Matsui, Kanako Minoda, Kanae Nasu, Risa Kikuchi, Keiichi Fukui, O. N.O. Hiroshi, Kiyoshi Matsumoto, Functional new acylated sophoroses and deglucosylated anthocyanins in a fermented red vinegar, Journal of Agricultural and Food Chemistry, 10.1021/jf901809p, 57, 18, 8331-8338, 2009.09, The new acylated polyphenols were isolated from a red-colored vinegar produced via fermentation with purple-fleshed sweet potato storage roots, and identified mainly by MS and NMR. The three acylated sophoroses were determined as 6-O-(E)-caffeoyl-(2-O-(6-O-acyl)-β-D-glucopyranosyl)-D-glucopyranoses, where acyl was (E)-caffeoyl, p-hydroxybenzoyl, and (E)-feruloyl, respectively. The four acylated anthocyanins were also determined as cyanidin 3-O-(6-O-(E)-caffeoyl-(2-O-(6-O-(E)-feruloyl)β-D-glucopyranosyl) -β-D-glucopyranoside), in addition to peonidin 3-O-(6-O-(E)-caffeoyl-(2-O- (6-O-acyl)D-glucopyranosyl)-β-D-glucopyranosides), where acyl was (E)-caffeoyl, p-hydroxybenzoyl, and (£)-feruloyl, respectively. The diacylated sophoroses showed higher antioxidant capacity than that of monoacylated analogue 6-caffeoylsophorose, so the multiacylation established to enhance their antioxidant capacity. Similarly, 5-deglucosylated anthocyanins also gave somewhat stronger antioxidation than corresponding sweet potato anthocyanins. In rat intestinal α-glucosidase inhibition study, the diacylated sophoroses preferably inhibited maltase rather than sucrase with an IC50 value of <300 μM, indicating a potential role as antidiabetic phytochemicals. These acylated polyphenols in a red vinegar were expected to play important functional roles for health..
135. Mitsuru Tanaka, Shimpei Watanabe, Zhengquan Wang, Kiyoshi Matsumoto, Toshiro Matsui, His-Arg-Trp potently attenuates contracted tension of thoracic aorta of Sprague-Dawley rats through the suppression of extracellular Ca2+ influx, Peptides, 10.1016/j.peptides.2009.05.012, 30, 8, 1502-1507, 2009.08, In the present study, we primarily attempted to identify di- and tri-peptides showing potent vasodilation in 1.0 μM phenylephrine-contracted thoracic aortas of Sprague-Dawley rats. Synthetic 15 Trp-His (WH) skeleton analogues were used for rat aorta ring's force measurements, since WH was found to be a vasoactive di-peptide so far. Among the synthesized peptides consisted of both His and Trp amino acid residues, His-Arg-Trp (HRW) was found to evoke the most potent vasodilation with an EC50 value of 1.2 ± 0.08 mM in an endothelium-independent manner, while no effect was evoked by a mixture of individual amino acids. In addition to the structure of tri-peptides-activity relationship, chemically modified HRW analogues, i.e., 1- or 3-methyl-His-Arg-Trp and His-citrulline-Trp demonstrated the structural importance of tri-peptide to evoke the vasoactivity as following factors: (1) Neutral imidazole and indole groups from His and Trp residues at N- and C-terminals, respectively and (2) basic amino acids at the middle position. In mitogen (10 μM angiotensin II or 50 μM Bay K8644)-stimulated vascular smooth muscle cells, vasoactive HRW (100 μM) caused significant [Ca2+]i reduction to an extent of >30%. Thus, our results suggest that HRW caused vasodilation action via an endothelium-independent mechanism which probably involves the suppression of extracellular Ca2+ influx through voltage-gated l-type Ca2+ channel..
136. Takashi Tanaka, Yuji Miyata, Kei Tamaya, Rie Kusano, Yosuke Matsuo, Shizuka Tamaru, Kazunari Tanaka, Toshiro Matsui, Masamichi Maeda, Isao Kouno, Increase of theaflavin gallates and thearubigins by acceleration of catechin oxidation in a new fermented tea product obtained by the tea-rolling processing of loquat (Eriobotrya Japonica) and green tea leaves, Journal of Agricultural and Food Chemistry, 10.1021/jf900963p, 57, 13, 5816-5822, 2009.07, In a project to produce a new fermented tea product from non-used tea leaves harvested In the summer, we found that kneading tea leaves (Camellia sinensis) with fresh loquat leaves (Eriobotrya japonica) accelerated the enzymatic oxidation of tea catechins. The fermented tea obtained by tea-rolling processing of tea and loquat leaves had a strong, distinctive flavor and a plain aftertaste, which differed from usual black, green, and oolong teas. The phenolic constituents were similar to those of black tea. However, the concentrations of theaflavin 3-O-gallate, theaflavin 3,3′-di-O-gallate, and thearubigins were higher in the tea leaves kneaded with loquat leaves than in tea leaves kneaded without loquat leaves. The results from in vitro experiments suggested that acceleration of catechin oxidation was caused by the strong oxidation activity of loquat leaf enzymes and a coupled oxidation mechanism with caffeoyl quinic acids, which are the major phenolic constituents of loquat leaves..
137. Mitsuru Tanaka, Shimpei Watanabe, Zhengquan Wang, Kiyoshi Matsumoto and Toshiro Matsui, His-Arg-Trp potently attenuates contracted tension of thoracic aorta of Sprague-Dawley rats through the suppression of extracellular Ca2+ influx, Peptides, 30, 1502-1507, 2009.06.
138. Toshiro Matsui, Mayu Shimada, Nozomi Saitoh and Kiyoshi Matsumoto, α-Glucosidase inhibition assay in an enzyme-immobilized amino-microplate, Anal.Sci. , 25(4), 559-562 (2009), 2009.04.
139. Masahiro Yoshiki, Keisuke Tsuge, Yumi Tsuruta, Takashi Yoshimura, Kazuyoshi Koganemaru, Toshihisa Sumi, Toshiro Matsui, Kiyoshi Matsumoto, Production of new antioxidant compound from mycosporine-like amino acid, porphyra-334 by heat treatment, Food Chemistry, 10.1016/j.foodchem.2008.08.087, 113, 4, 1127-1132, 2009.04, In this study, we evaluated the antioxidant activity (diphenylpicrylhydrazyl (DPPH)-radical scavenging activity) of the low-molecular weight fraction of water-soluble Susabinori (Porphyra yezoensis) extract (LMF). DPPH-radical scavenging activity of LMF (65.5 μmol-Trolox eq/ml) was enhanced at temperatures over 100 °C (1.4, 2.0 and 2.4 times higher at 100, 110 and 120 °C, respectively). As a result of HPLC separations, a newly produced peak was observed in heat treated LMF, while a marked decrease of another peak was found after heat treatment of LMF. The decreased peak was identified as porphyra-334, which is a typical mycosporine-like amino acid, by ESI/MSn analysis (protonated molecule [M + H]+ at m/z 347.1 and its fragment ion 303.1). The newly produced compound with [M + H]+ at m/z 329.1 was found to be a dehydrated compound of porhyra-334. The compound exhibited an extremely high-IC50 value of 10.1 μg/ml in DPPH-radical scavenging activity, compared to porphyra-334 (>1000 μg/ml)..
140. Toshiro Matsui, Mayu Shimada, Nozomi Saito, Kiyoshi Matsumoto, α-Glucosidase inhibition assay in an enzyme-immobilized amino-microplate, Analytical Sciences, 10.2116/analsci.25.559, 25, 4, 559-562, 2009.04, α-Glucosidase (AGH) from the small intestine of rat was immobilized onto a glutaradehyde (GA) activated NH2-96 well microplate to establish a convenient and rapid AGH inhibition assay system. After AGH immobilization, remaining GA groups were blocked by β-alanine to induce a negative charge on the surface of the well. The AGH-plate showed an enzyme activity of 444 nU/well under an assayed condition at 37°C for 2 h using 0.3 mM 4-methylumbelliferyl-α-D- glucopyranoside as a fluorogenic substrate. Inhibitory powers of voglibose and acarbose as therapeutic AGH inhibitors were successfully evaluated to have IC50 values of 13 and 114 nM, respectively. 2009.
141. Masahiro Yoshiki, Keisuke Tsuge, Yumi Tsuruta, Takashi Yoshimura, Kazuyoshi Koganemaru, Toshihisa Sumi, Toshiro Matsui, Kiyoshi Matsumoto, Production of a new antioxidant compound from mycosporine-like amino acid, Porphyra-334, by heat treatment., Food Chem., 113, 1127-1132 , 2009.01.
142. Hiroshi Matsufuji, Ryoichiro Sasa, Yuki Honma, Hiromi Miyajima, Makoto Chino, Takeshi Yamazaki, Tomoko Shimamura, Hiroyuki Ukeda, Toshiro Matsui, Kiyoshi Matsumoto, Kazuo Yamagata, 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity of binary mixtures of antioxidants, Nippon Shokuhin Kagaku Kogaku Kaishi, 10.3136/nskkk.56.129, 56, 3, 129-136, 2009, The effect of a binary mixture of antioxidants on the l,l-diphenyl-2- picrylhydrazyl (DPPH) radical scavenging activity was investigated using 11 antioxidants as food additives or 24 natural antioxidants. Among 55 combinations of binary mixtures, including 11 antioxidants, BHA, BHT, catechin, quercetin, sesamol, ferulic acid, gallic acid, morin, ellagic acid, α-tocopherol, and δ-tocopherol, the DPPH radical scavenging activity of 36 combinations were significantly greater than the expected activity of individual antioxidants, resulting in synergistic effects. Also, one combination showed antagonistic effect. Among 276 combinations of 24 natural antioxidants, including 4 benzoic acids, 3 cinnamic acids, 12 flavonoids, 2 vitamins, and 3 diterpenes, 74 showed synergistic effects and 61 showed antagonistic effects. However, the ratios of the actual to expected activity of many synergistic and antagonistic combinations were about 1.1- 1.2 and 0.8-0.9, respectively..
143. Toshiro Matsui, Sachiko Korematsu, Eui Baek Byun, Taichi Nishizuka, Shunji Ohshima, Tomomasa Kanda, Apple procyanidins induced vascular relaxation in isolated rat aorta through NO/cGMP pathway in combination with hyperpolarization by multiple K + channel activations, Bioscience, Biotechnology and Biochemistry, 10.1271/bbb.90334, 73, 10, 2246-2251, 2009, Apple (Malus pumila) procyanidins led to a potent vasorelaxation effect μMin 1.0 μM phenylephrine-contractive rat thoracic aorta. Relaxation was greatly reduced by 70 mm KCl as well as by removal of the endothelium, suggesting that it was associated with endothelium- dependent hyperpolarization. Neither cAMP synthesis inhibition nor NAD(P)H oxidase inhibition abolished the effect. In contrast, complete abolition by a soluble guanylyl cyclase inhibitor revealed that apple procya- nidins were mainly involved in the cGMP production pathways. In the presence of NG-monoethyl-l-arginine or tetraethylammonium chloride, the effect was still observed at higher concentrations (>25 μ, g/ml), while their combination completely diminished the effect. Vasorelaxation was to some extent affected by paxillin, apamin and glybenclamide, and was greatly affected by 4-aminopyridine and by BaCl2. These results indicate that procyanidin-induced vasorelaxation is associated with NO-cGMP pathway in combination with hyper- polarization due to multiple activation of Ca2+-dependent and -independent K + channels..
144. Yuji Miyata, Masayuki Noda, Kei Tamaya, Seigo Hayashida, Tomonori Tokushima, Shoko Nishizono, Toshiro Matsui, Takashi Tanaka, Shizuka Tamaru, Kazunari Tanaka, Development of new fermented tea by mixed kneading of third crop of green tea leaves and loquat leaves, Nippon Shokuhin Kagaku Kogaku Kaishi, 10.3136/nskkk.56.647, 56, 12, 647-654, 2009, The third crop of green tea leaves contains a relatively large amount of catechins, giving its hot-water extract a bitter taste. The loquat leaves have strong enzymatic activity of catechin oxidization and contain chlorogenic acid which accelerates this oxidation. We investigated the production method of fermented tea by mixed kneading of the third crop of green tea leaves and loquat leaves and examined the most appropriate time to harvest green tea leaves. Fresh green tea leaves (27 kg) were withered by blowing air over them (70°C) for 20 min in a primary tea-rolling dryer. The tea leaves were then mixed with fresh loquat leaves (3 kg) and kneaded with a tea roller at room temperature for 20 min. The amount of catechins in the green tea leaves was decreased by this process, resulting in hot-water extract of mixed tea leaves that was bright red and had improved taste and aroma. The best quality fermented tea was produced from the third crop of green tea leaves harvested 35 days after the second crop harvest. We established a new production method to manufacture fermented tea by mixed kneading of the third crop of green tea leaves and loquat leaves using a primary tea-rolling dryer and tea roller. Using this method, good quality fermented tea was manufactured..
145. Yusuke Ushida, Toshiro Matsui, Mitsuru Tanaka, Kiyoshi Matsumoto, Hirokazu Hosoyama, Atsuhiro Mitomi, Yuko Sagesaka, Takami Kakuda, Endothelium-dependent vasorelaxation effect of rutin-free tartary buckwheat extract in isolated rat thoracic aorta. , J. Nutr. Biochem., 19(10), 700-707, 2008.10.
146. Lieselot Vercruysse, Guy Smagghe, Toshiro Matsui, John Van Camp, Purification and Identification of an Angiotensin I-converting Enzyme (ACE) Inhibitory Peptide from the Gastrointestinal Hydrolysate of the Cotton Leafworm, Spodoptera Littoralis. , Process Biochem., 43, 900-904, 2008.10.
147. Tomoko Fujise, Norihiko Terahara, Keiichi Fukui, Koichi Sugita, Hideaki Ohta, Toshiro Matsui, Kiyoshi Matsumoto, Durable antihyperglycemic effect of 6-O-caffeoylsophorose with α-glucosidase inhibitory activity in rats., Food Sci. Technol. Res., 14(5), 477-484, 2008.10.
148. Yusuke Ushida, Toshiro Matsui, Mitsuru Tanaka, Kiyoshi Matsumoto, Hirokazu Hosoyama, Atsuhiro Mitomi, Yuko Sagesaka, Takami Kakuda, Endothelium-dependent vasorelaxation effect of rutin-free tartary buckwheat extract in isolated rat thoracic aorta, Journal of Nutritional Biochemistry, 10.1016/j.jnutbio.2007.09.005, 19, 10, 700-707, 2008.10, The aim of this study was to point out the potential of tartary buckwheat on vascular functions. A nonabsorbed fraction of hot-water extract of tartary buckwheat on a SP70 column (TBSP-T), which was free from rutin, was used for this aim. In a contractile experiment using Sprague-Dawley rat thoracic aorta rings contracted by 1.0 μM phenylephrine (PE) or 50 mM KCl, TBSP-T evoked a significant vasorelaxation [EC50 (mg/ml): PE; 2.2; KCl, 1.9]. By a further fractionation of TBSP-T by liquid-liquid partitioning into basic, neutral and acidic fractions, a marked enhancement of vasorelaxation effect was observed only for acidic fraction (EC50, 0.25 mg/ml). The action of acidic fraction was significantly attenuated in endothelium-denuded aortic rings and in the presence of nitric oxide synthase inhibitor, NG-monomethyl-l-arginine (100 μM). The fraction also enhanced the cyclic guanosine monophosphate (cGMP) production in aortic rings contracted with PE [cGMP (pmol/mg protein): PE, 7.2±2.3; PE+Acidic fraction, 35±8]. These results indicate that acidic fraction could mediate NO/cGMP pathways, thereby exerting endothelium-dependent vasorelaxation action. In conclusion, tartary buckwheat was proven to regulate vascular tones and have latent acidic candidates except for rutin..
149. Norihiko Terahara, Toshiro Matsui, Structures and functionalities of acylated anthocyanins, Functional Food and Health, 10.1021/bk-2008-0993.ch009, 993, 90-101, 2008.09, Anthocyanins are polyphenolic glycoside pigments widely distributed in the plant kingdom. Recently, along with health trend against aging, anthocyanins have attracted much attention as functional food factors that prevent life-style related diseases. To develop new stable anthocyanin materials, we elucidated a correlation between the structures and the functionalities of acylated anthocyanins with two or more aromatic acids in the plant materials such as a purple sweet potato storage root and a butterfly-pea flower. Of the functionalities, the antioxidative activity was evaluated on the basis of DPPH radical scavenging activity and lipid peroxidation inhibitory activity. It was demonstrated that aglycone and/or aromatic acids with free phenolic hydroxyl groups on neighboring positions and only aromatic acids at outer sides in polyacylated anthocyanin molecules (folded in solutions) were more effective for the antioxidative activity..
150. Lieselot Vercruysse, Guy Smagghe, Toshiro Matsui, John Van Camp, Purification and identification of an angiotensin I converting enzyme (ACE) inhibitory peptide from the gastrointestinal hydrolysate of the cotton leafworm, Spodoptera littoralis, Process Biochemistry, 10.1016/j.procbio.2008.04.014, 43, 8, 900-904, 2008.08, Enzymatic hydrolysis of the protein from an edible insect species, the cotton leafworm Spodoptera littoralis (Lepidoptera) leads to the release of angiotensin I converting enzyme (ACE) inhibitory peptides. The subsequent hydrolysis with pepsin, trypsin and α-chymotrypsin was designed to simulate the human gastrointestinal digestion process. After fractionation of this hydrolysate using consecutive chromatographic techniques, including size exclusion chromatography and reverse-phase high-performance liquid chromatography, a new ACE inhibitory tripeptide was identified. The amino acid sequence of the tripeptide was determined as Ala-Val-Phe and the in vitro ACE inhibitory activity assay revealed an IC50 value of 2123 μM..
151. Isiaka A. Ogunwande, T. Matsui, K. Matsumoto, M. Shimoda and D. Kubmarawa, Constituent of the essential oil from the leaves of Acacia Tortilis (Forsk.) hayne. , J. Essential Oil Research, 20(2), 116-119, 2008.06.
152. Mitsuru Tanaka, Shinpei Watanabe, Mai Tokuyasu, Toshiro Matsui, Kiyoshi Matsumoto, Structure-activity relationship between vasodilating di- and tri-peptides in thoracic aorta of Sprague-Dawley rats. , J. Hypertension, 26(suppl.1), S171, 2008.06.
153. Mitsuru Tanaka, Mai Tokuyasu, Toshiro Matsui, Kiyoshi Matsumoto, Endothelium-independent vasodilation effect of di- and tri-peptides in thoracic aorta of Sprague-Dawley rats, Life Sciences, 10.1016/j.lfs.2008.02.001, 82, 15-16, 869-875, 2008.04, The goal of this study was to elucidate the structure-activity relationship for vasodilating peptides and their underlying mechanism. In this study, we synthesized 62 di- and tri-peptides having aromatic amino acid residues (Tyr, Trp and Phe). Among them, only 4 peptides (HW, WH, WL and WV) evoked an apparent vasodilating effect in 50 mM KCl-contracted aortic rings in the descending order of WH>HW>WL>WV; WH showed the vasodilating activity with an EC50 of 3.4 mM. Within our experimental results, it seems likely that Trp residue at the N-terminal would play a role in eliciting vasodilating effect. No appearance of vasodilating effect for stereoisomers of WH with D-configuration revealed that the vessel would recognize the l-configuration of WH. The presence of angiotensin I-converting enzyme (ACE) inhibitor (50 nM enalaprilat) did not affect the WH-induced vasodilating effect, though WH showed a slight ACE inhibitory activity (IC50: 93 μM). The effect was also observed in the endothelium-denuded aortic rings. In contrast, WH provoked a significant displacement to the right in the vasodilating curve in the presence of 30 nM verapamil, while no shift was observed in the presence of 2.5 nM nifedipine. These results indicate that WH, a vasodilating di-peptide, would exert a vasodilation via the suppression of Ca2+ influx into KCl-induced depolarized aortic rings. The present study also suggests that the binding site of WH to the Ca2+ channel may be competitive to that of phenylalkylamine-type voltage-gated L-type Ca2+ channel blocker..
154. Xiao-Lin Zhu, Keisuke Watanabe, Koso Shiraishi, Tatsuro Ueki, Yoshiharu Noda, Toshiro Matsui, Kiyoshi Matsumoto, Identification of ACE-inhibitory Peptides in Salt-free Soy Sauce that are Transportable across Caco-2 Cell Monolayers, Peptides, 29(3), 338-344 , 2008.03.
155. Xiao Lin Zhu, Keisuke Watanabe, Koso Shiraishi, Tatsuro Ueki, Yoshiharu Noda, Toshiro Matsui, Kiyoshi Matsumoto, Identification of ACE-inhibitory peptides in salt-free soy sauce that are transportable across caco-2 cell monolayers, Peptides, 10.1016/j.peptides.2007.11.006, 29, 3, 338-344, 2008.03, In present study, we aimed to identify angiotensin I-converting enzyme (ACE)-inhibitory peptides from a salt-free soy sauce (SFS), a newly developed antihypertensive seasoning obtained by Aspergillus oryzae fermentation of soybean in the absence of salt, which can be transported through caco-2 cell monolayers. Through an Ussing transport investigation of SFS across caco-2 cell monolayers, three di-peptides, Ala-Phe, Phe-Ile and Ile-Phe, were successfully identified from the SFS as transportable inhibitory peptides. Ala-Phe and Ile-Phe, but not Phe-Ile, exhibited ACE-inhibitory activity with IC50 values of 165.3 μM and 65.8 μM, respectively. Kinetic studies revealed that Ile-Phe (Km: 3.1 mM, Papp: 2.4 × 10-6 cm/s) exhibited greater affinity toward the transport compared with Ala-Phe (Km: 48.1 mM, Papp: 1.4 × 10-6 cm/s) and Phe-Ile (Km: 12.7 mM, Papp: 1.4 × 10-6 cm/s)..
156. Isiaka A. Ogunwande, Toshiro Matsui, Kiyoshi Matsumoto, Mitsuya Shimoda, D. Kubmarawa, Constituents of the Essential Oil from the Leaves of Acacia tortilis (Forsk.) Hayne, Journal of Essential Oil Research, 10.1080/10412905.2008.9699969, 20, 2, 116-119, 2008.01, The chemical composition of the essential oil from the leaves of Acacia tortilis, collected from Ogbomoso, Nigeria, was analyzed by means of GC-FID and GC/MS. Seventy-five compounds were identified. The oil was dominated by a large amount of sesquiterpenoid compounds (52.2%). The major components of the oil were α-humulene (12.0%), α-cadinol (10.6%), nerolidol (9.9%), γ-cadinene (7.4%) and 2-(E)-octenal (6.0%)..
157. Tomoko Fujise, Toshiro Matsui, Kiyoshi Matsumoto, Norihiko Terahara, Keiichi Fukui, Koichi Sugita, Tomoko Fujise, Hideaki Ohta, Durable Antihyperglycemic Effect of 6-O-Caffeoylsophorose with α-Glucosidase Inhibitory Activity in Rats, Food Science and Technology Research, 10.3136/fstr.14.477, 14, 5, 477-484, 2008, To evaluate the duration of antihyperglycemic effects of 6-O-caffeoylsophorose (CS), a newly identified natural α-glucosidase inhibitor from fermented purple-sweet potato, a single oral administration of CS was given to maltose-loaded Sprague-Dawley rats. Administration of CS (200 mg/kg) 30 min or 60 min before maltose administration produced an elevation of blood glucose level by administration of 2 g/kg of maltose in rats that was significantly lower than for no administration (control). In contrast, simultaneous or pro-administration of CS with maltose eliminated the antihyperglycemic effect. CS significantly reduced rat intestinal α-glucosidase activity in all of the small intestinal mucosal regions with a maximal reduction ratio of ca. 40% up to 60 min after CS administration. Thereafter, the intestinal α-glucosidase activity tended to return to basal level. These findings suggest that the antihyperglycemic effect of CS is restricted to pre-administration within 60 min..
158. Yujin Shigeta, Yasushi Aoyama, Takashi Okazaki, Toshiro Matsui, Kenji Namba, Growth inhibition of microorganisms by hydrostatic pressure in autolytic hydrolysis of unsalted squid liver, Nippon Shokuhin Kagaku Kogaku Kaishi, 10.3136/nskkk.55.117, 55, 3, 117-120, 2008, Inhibition of bacterial growth in unsalted squid liver by autolytic hydrolysis under hydrostatic pressure (AHHP) to produce seasoning was investigated. The desirable temperature for AHHP at 60 MPa was in a range of 45-55°C, and hydrostatic pressure had no effect on the autolysis in a range of 60-300 MPa. Squid liver was almost degraded for 24-48 h under the conditions of 60 MPa and 50°C. The autolysate contained taste-active amino acids, such as Glu, Asp and Ala, at high concentration. Although the Cd concentration of the autolysate decreased from 45 to 32 ppm, it remained at a sufficiently high level to use the autolysate as seasoning. The removal of Cd from the autolysate must be further investigated..
159. Isiaka A. Ogunwande, T. Matsui, K. Matsumoto, M. Shimoda and D. Kubmarawa, Constituent of the essential oil from the leaves of Acacia Tortilis (Forsk.) hayne, J. Essential Oil Research, 2007.10.
160. Xiao-Lin Zhu, Toshiro Matsui, Keisuke Watanabe, Koso Shiraishi, Tatsuro Ueki, Kiyoshi Matsumoto, Simultaneous determination of angiotensin I-converting enzyme inhibitory peptides in tryptic casein hydrolysate by high-performance liquid chromatography combined with a replicate heart-cut column-switching technique, J. Agric. Food Chem., 55(21), 8367-8374 , 2007.10.
161. Xiao Lin Zhu, Toshiro Matsui, Keisuke Watanabe, Koso Shiraishi, Tatsuro Ueki, Kiyoshi Matsumoto, Simultaneous determination of angiotensin I-converting enzyme inhibitory peptides in tryptic casein hydrolysate by high-performance liquid chromatography combined with a replicate heart-cut column-switching technique, Journal of Agricultural and Food Chemistry, 10.1021/jf0720584, 55, 21, 8367-8371, 2007.10, A replicate heart-cut column-switching HPLC method combined with two switching valves was newly developed for the simultaneous determination of three antihypertensive peptides (Ala-Phe, Tyr-Pro, and Trp-Tyr) in tryptic casein hydrolysate in one run-in assay. After a first separation on an octadecyl silane (ODS) column, heart-cuts of each peptide were individually separated on a subsequent analytical ODS column: 26% acetonitrile for Ala-Phe and Tyr-Pro (32% for Trp-Tyr) in 0.1% trifluoroacetic acid containing 10 mM sodium 1-octanesulfonate at 0.8 mL/min. Ala-Phe, Tyr-Pro, and Trp-Tyr in casein hydrolysate were determined within 70 min to be 0.377 ± 0.037 mg/g, 2.50 ± 0.26 mg/g, and 0.096 ± 0.008 mg/g, respectively..
162. Isiaka Ajani Ogunwande, Toshiro Matsui, Tomoko Fujise and Kiyoshi Matsumoto, α-Glucosidase Inhibitory Profile of Nigerian Medicinal Plants in Immobilized Assay System, Food Sci. Technol. Res., 13(2), 169-172, 2007.05.
163. Isiaka Ajani Ogunwande, Toshiro Matsui, Tomoko Fujise, Kiyoshi Matsumoto, α-Glucosidase inhibitory profile of Nigerian medicinal plants in immobilized assay system, Food Science and Technology Research, 10.3136/fstr.13.169, 13, 2, 169-172, 2007.05, Four Nigerian medicinal plants used for the treatment of various ailments in traditional ethnomedicine were evaluated for their anti-diabetic potential. The plants Irvingia gabonensis (O'Rorke) Bail, Eucalyptus torreliana F.v. Muell, Securidata longependuculata Fers and Murraya panicutata (L.) Jack were used in the study. Only the aqueous extract of I. gabonensis exhibited a potent maltase-inhibitory activity with an IC50 of O.10mg/mL, as well as a sucrase-inhibitory activity (IC50 of O.llmg/mL), whereas α-amylase inhibitory activity was quite poor (IC50 of 0.53 mg/mL). A significant lowering of the blood glycemie response to maltose ingestion in 8-week old Sprague-Dawley rats was observed at a dose of 300 mg/kg, in response to significant reduction in postprandial insulin response level..
164. Toshiro Matsui, Takashi Tanaka, Satomi Tamura, Asami Toshima, Kei Tamaya, Yuji Miyata, Kazunari Tanaka, and Kiyoshi Matsumoto, Alpha-Glucosidase Inhibitory Profile of Catechins and Theaflavins, J.Agric. Food Chem., 55(1), 99-105, 2007.01.
165. A succesive determination of anthocyanins in purple sweet potato.
166. Toshiro Matsui, Takashi Tanaka, Satomi Tamura, Asami Toshima, Kei Tamaya, Yuji Miyata, Kazunari Tanaka, Kiyoshi Matsumoto, α-glucosidase inhibitory profile of catechins and theaflavins, Journal of Agricultural and Food Chemistry, 10.1021/jf0627672, 55, 1, 99-105, 2007.01, To clarify the postprandial glucose suppression effect of flavonoids, the inhibitory effects of catechins and theaflavins against α-glucosidase (AGH) were examined in this study. It was initially demonstrated that theaflavins and catechins preferentially inhibited maltase rather than sucrase in an immobilized AGH inhibitory assay system. For the maltase inhibitory effects of theaflavins, the effects were observed in descending order of potency of theaflavin (TF)-3-O-gallate (Gal) > TF-3,3′-di-O-Gal > TF-3′-O-Gal > TF. This suggests that the AGH inhibition induced by theaflavins is closely associated with the presence of a free hydroxyl group at the 3′-position of TF as well as the esterification of TF with a mono-Gal group. In addition, the R-configuration at the 3′-position of TF-3-O-Gal showed a higher inhibitory activity than the S-configuration. As a result of a single oral administration of maltose (2 g/kg) in rats, a significant reduction in blood glucose level was observed at a dose of 10 mg/kg of TF-3-O-Gal, demonstrating for the first time that TF-3-O-Gal can suppress glucose production from maltose through inhibition of AGH in the gut..
167. Tomoko Shimamura, Ritaro Matsuura, Takashi Tokuda, Naoki Sugimoto, Takeshi Yamazaki, Hiroshi Matsufuji, Toshiro Matsui, Kiyoshi Matsumoto, Hiroyuki Ukeda, Comparison of conventional antioxidants assays for evaluating potencies of natural antioxidants as food additives by collaborative study, Nippon Shokuhin Kagaku Kogaku Kaishi, 10.3136/nskkk.54.482, 54, 11, 482-487, 2007, In recent years, there has been a need for a new quality criterion for antioxidants based on its antioxidative activity in Japan. In particular, novel official methods of evaluating the antioxidative activities of food additives are required. In order to investigate the possibility of developing official methods, the reproducibilities of three simple conventional antioxidant assays (DPPH assay, ABTS assay, and WST-1 assay) based on spectrophotometric detection were evaluated by collaborative study between three laboratories. DPPH and ABTS assays were performed to evaluate the antioxidant activity (TEAC, Trolox equivalent activity) of all nine antioxidants used in this study, whereas the WST-1 assay was suitable for evaluating the superoxide dismutase (SOD)-equivalent activity of seven antioxidants (excepting D-α-tocopherol and D-δ-tocopherol). The HorRat values from the collaborative study revealed that the DPPH and ABTS assays showed higher reproducibility than the WST-1 assay. It was assumed that the lower reproducibility would be due to the measuring principle, because the WST-1 assay, unlike the DPPH and the ABTS assays, is a competitive enzyme assay. Based on the results, we concluded that the DPPH and ABTS assays would be candidates in validation studies of methods for the purpose of developing an official methodology..
168. Norihiko Terahara, Tomoyuki Oki, Toshiro Matsui, Keiichi Fukui, Koich Sugita, Kiyoshi Matsumoto, Ikuo Suda, Simultaneous determination of major anthocyanins in purple sweet potato, Nippon Shokuhin Kagaku Kogaku Kaishi, 10.3136/nskkk.54.33, 54, 1, 33-38, 2007, A simultaneous determination method using HPLC was carried out to determine the net content of anthocyanins (AN) in purple sweet potatoes (PS) and processed foods made from them. The optimum HPLC conditions, which allowed good separation of the peaks of eight major ANs (named YGM-1a, -1b, -2, -3, -4b, -5a, -5b and -6) in the storage root of PS cultivar Ayamurasaki, were set by employing formic acid as an acidified solvent. Under these conditions, analysis was conducted in 40 min, which is considerably shorter than the time taken in previous experiments. In HPLC analysis of standard pigment YGM-6, the calibration curve showed a good linear correlation between concentration and peak area in the concentration range 10-6-10-3 M, and the detection limit for analysis was less than 11 ng. Moreover, the introduction of a quantitative factor by comparison of a standard YGM-6 peak area with the experimental YGM peak areas simplified the simultaneous determination. This method was applied to fresh PS, dried PS powder and processed PS-based beverages (a carbonated drink and a fermented vinegar). The total major AN content was 369.1 mg/100 g in raw PS (cv. Ayamurasaki), with YGM-4b present in the largest amount, and peonidin-based ANs making up 81% of total AN levels. The compositions of major ANs in the dried powder, carbonated drink and fermented vinegar were similar to that of raw PS, with the total contents at 196.9 mg/100 g, 118.7 mg/100 g and 15.3 mg/100 g, respectively..
169. Toshiro Matsui, Kiyoshi Matsumoto, Antihypertensive peptides from natural resources, Advances in Phytomedicine, 10.1016/S1572-557X(05)02015-5, 2, C, 255-271, 2006.12, Blood pressure is regulated by many physiological systems in humans. In the vasopressor system, for example the renin-angiotensin system is thought to play an important role, where angiotensin II, which is produced from the cleavage of angiotensin I by angiotensin I-converting enzyme (ACE) shows a potent vasocontractive activity. In this review, preparation of bioactive peptides from natural resources as well as their underlying antihypertensive mechanism will be discussed..
170. Toshiro Matsui, Xiao Lin Zhu, Keisuke Watanabe, Keisuke Tanaka, Yoko Kusano, Kiyoshi Matsumoto, Combined administration of captopril with an antihypertensive Val-Tyr di-peptide to spontaneously hypertensive rats attenuates the blood pressure lowering effect, Life Sciences, 10.1016/j.lfs.2006.08.013, 79, 26, 2492-2498, 2006.11, Some di-peptides have been proven to exert an antihypertensive effect in mild-hypertensive subjects. The aim of this study was to clarify whether combined administration of an ACE inhibitor, captopril, with an antihypertensive di-peptide Val-Tyr (VY) would alter their potent antihypertensive effects in spontaneously hypertensive rats (SHRs). Single oral administration of captopril (2.5 mg/kg), VY (25 mg/kg), or captopril (2.5 mg/kg) + VY (25 mg/kg) to 18-week-old male SHRs was performed. Systolic blood pressure (SBP) was measured up to 9 h, and plasma captopril concentrations were determined. A transport study of captopril and/or VY across living rat jejunum from SHRs was also performed to evaluate the kinetics of absorption. Combined administration of captopril with VY failed to lower the BP during the 9-h experiment. A transport study of captopril or VY revealed that VY inhibited captopril transport, and vice versa, in a competitive manner and exhibited an approximately 1/3-fold lower Ki value for captopril compared with that for VY; indicating that both compounds compete for the same membrane transport pathway. A 50% decrease in plasma captopril levels by combined administration with VY supported that the attenuation of the BP lowering effect was due to inhibition of captopril uptake by VY. Consequently, our findings suggest that subjects treated with ACE inhibitors for hypertension should avoid combined-intake with antihypertensive foods that are rich in small peptides due to the competitive inhibition of drug uptake by these peptides..
171. Xiao Lin Zhu, Keisuke Tanaka, Toshiro Matsui, Kiyoshi Matsumoto, Antihypertensive effect of captopril is greatly attenuated by combined administration of with antihypertensive peptide, Journal of Hypertension, 24(suppl.6), S204, 2006.10.
172. Yusuke Ushida, Toshiro Matsui, Kiyoshi Matsumoto, Hirokazu Hosoyama, Atsuhiro Mitomi, Yuko Sagesaka, Takami Kakuda, Endothelium-dependent vasolidating effect of buckwheat extract on rat aortas, Journal of Hypertension, 24(suppl.6), S319, 2006.10.
173. Mitsuru Tanaka, Mai Tokuyasu, Toshiro Matsui, Kiyoshi Matsumoto, A screening of bioactive peptide possessing vasodilating action, Journal of Hypertension, 24(suppl.6), S407, 2006.10.
174. Mitsuru Tanaka, Toshiro Matsui, Yusuke Ushida, Kiyoshi Matsumoto, Vasodilating effect of di-peptides in thoracic aortas from spontaneously hypertensive rats, Bioscience, Biotechnology and Biochemistry, 10.1271/bbb.60119, 70, 9, 2292-2295, 2006.10, In this study, we found that antihypertensive di-peptide Val-Tyr (VY) showed a vascular relaxation effect in KCl-induced contraction of thoracic aorta rings from 18-week-old spontaneously hypertensive rats among di-peptides of VY, Ile-Tyr, and Tyr-Val irrespective of their angiotensin I-converting enzyme inhibitory activity. The effect was endothelium-independent, and was closely associated with vascular responses in the vascular smooth muscle layer..
175. Mitsuru Tanaka, Toshiro Matsui, Yusuke Ushida and Kiyoshi Matsumoto, Vasodilating action of di-peptides in thoracic aortas from spontaneously hypertensive rats, Biosci. Biotechnol. Biochem., 70(9), 2292-2295, 2006.09.
176. Toshiro Matsui, Xiao Lin Zhu, Keisuke Watanabe, Keisuke Tanaka, Yoko Kusano, Kiyoshi Matsumoto, Combined administration of captopril with an antihypertensive Val-Tyr di-peptide to spontaneously hypertensive rats attenuates the blood pressure lowering effect, Life Sciences, 2006.08.
177. Toshiro Matsui, Isiaka Ogunwande, Kanthi J. M. Abesundara, and Kiyoshi Matsumoto, Anti-hyperglycemic Potential of Natural Products, Mini-Reviews in Medicinal Chemistry, 6(3), 109-120, 2006.02.
178. Toshiro Matsui, Akiko Yukiyoshi, Shima Doi, Hiroya Ishikawa, Kiyoshi Matsumoto, Enzymatic hydrolysis of ethanol-insoluble proteins from royal jelly and identification of ACE inhibitory peptides, Nippon Shokuhin Kagaku Kogaku Kaishi, 10.3136/nskkk.53.200, 53, 4, 200-206, 2006, In order to develop a physiologically functional food material from Royal Jelly (RJ) proteins precipitated by ethanol, we tried to hydrolyze them using various proteases. As a result of 0.4 wt%-2 h Orientase ONS hydrolysis treatment of ethanol-insoluble RJ proteins at 50°C, a newly obtained hydrolysate exhibited strong angiotensin I-converting enzyme (ACE) inhibitory activity (IC50: 0.082 mg/ml). Single-dose, oral administration of the hydrolysate (1 g/kg of rat weight) in 13-week spontaneously hypertensive rats resulted in a significant reduction in the systolic blood pressure of ca. 12 mmHg (P<0.05) at 2 and 6 h after administration. By performing gel permeation chromatography of the hydrolysate, followed by reversed phase HPLCs, eight ACE inhibitory peptides were isolated and identified. Trp-Val-Leu (IC50: 32.4 μM) and Tyr-Tyr-Ser-Pro (IC50: 1.3 μM) were identified from natural resources for the first time. Some of the ACE inhibitory peptides were derived from the RJ-glycoprotein. Consequently, ethanol-insoluble RJ protein is thought to be a good resource as an antihypertensive food material..
179. Keiichi Fukui, Kazusato Matsugano, Kouichi Sugita, Norihiko Terahara, Toshiro Matsui, Kiyoshi Matsumoto, Large-scale preparation of 6-O-caffeoylsophorose from acylated anthocyanins in purple sweet potato, Nippon Shokuhin Kagaku Kogaku Kaishi, 10.3136/nskkk.53.214, 53, 4, 214-217, 2006, 6-O-caffeoylsophorose(CS) is a functional component of vinegar produced by the acetic fermentation of storage roots of purple sweet potato (cultivar Ayamurasaki). Large-scale preparation of CS was examined using a synthetic absorbent resin, Diaion HP20. The CS-rich preparation produced by heat cleavage in acidic conditions from purple sweet potato pigment (PSP) was purified by the HP20 open column method. However, a high purity of CS was not achieved due to the co-elution of chlorogenic acid. To remove the interfering chlorogenic acid, PSP was applied to the column and eluted with 15% ethanol, resulting in the elution of chlorogenic acid while the anthocyanins were absorbed to the resin. We were thus able to obtain chlorogenic acid-free PSP (CF-PSP) with a recovery ratio of approximately 66%. As a result of the purification of CS from heat-treated CF-PSP, we obtained CS with a purity of 80% at a recovery ratio of approximately 12%..
180. Production of 6-O-Caffeolysophorose of acylated anthocyanins from puple sweet potato by weak acid hydrolysis.
181. T.Ueno, M.Tanaka, T.Matsui, K.Matsumoto, Determination of Antihypertensive Small Peptides, Val-Tyr and Ile-Val-Tyr, by Fluorimetric High-Performance Liquid Chromatography Combined with a Double Heart-Cut Column-Switching Technique, Anal.Sci., 10.2116/analsci.21.997, 21, 8, 997-1000, 21, 997-1000, 2005.07.
182. T.Matsui, T.Ueno, M.Tanaka, H.Oka, T.Miyamoto, K.Osajima, K.Matsumoto, Antiproliferative action of an angiotensin I-converting enzyme inhibitory peptide, Val-Tyr, via an L-type Ca2+ channel inhibition in cultured vascular smooth muscle cells, Hypertension Res., 10.1291/hypres.28.545, 28, 6, 545-552, 28(6), 545-552, 2005.06.
183. Antihypertensive effect of Mirin, a fermented traditional product, in SHRs.
184. Isolation of ACE inhibitory peptides from Mirin, a fermented traditional product.
185. H.Ishikawa, T.Matsui, T.Ohtsu, K.Watanabe, K.Matsumoto, K.Matsumoto, pH of solution greatly affects a sorption of ionized compounds into plastic film, J.Agric. Food Chem., 10.1021/jf047906z, 53, 9, 3488-3492, 53(9), 3488-3492, 2005.04.
186. Keiichi Fukui, Kazusato Matsugano, Norihiko Terahara, Toshiro Matsui, Kiyoshi Matsumoto, Production of 6-O-caffeoylsophorose from acylated anthocyanins derived from purple sweet potato through hydrolysis under weak acidic conditions, Nippon Shokuhin Kagaku Kogaku Kaishi, 52, 7, 306-310, 2005, 6-O-caffeoylsophorose (CS) is a functional component identified in vinegar produced through acetic fermentation of storage roots of purple sweetpotato cultivar Ayamurasaki. The optimum conditions of CS production was investigated using the purple sweetpotato pigment (PSP) separated from Ayamurasaki containing acylated anthocyanins in order to develop the efficient production method of CS. By heating PSP under weak acidic conditions, CS as the side chain fragment of acylaled anthocyanins was produced abundantly. The amount of produced CS was dependent on pH, and highest at pH 3.0, not on the kind difference of acids. The temperature was also an important factor to the concentration of CS : at higher temperatures the highest score was obtained in shorter time. The ratio of the highest score to anthocyanin content in original PSP was almost same at each temperature and production efficiency of CS was also similar in quantity..
187. T.Matsui, S. Ebuchi, K.Fukui, K. Matsugano, N.Terahara, K.Matsumoto, Caffeoylsophorose, a new natural a-glucosidase inhibitor, from red vinegar by fermented purple-fleshed sweet potato, Biosci. Biotechnol. Biochem., 10.1271/bbb.68.2239, 68, 11, 2239-2246, 68, 332-339, 2004.11.
188. T.Matsui, S.Ebuchi, T.Fujise, K.J.M.Abesundara, S.Doi, H.Yamada, K.Matsumoto, Strong antihyperglycemic effects of water-soluble fraction of Brazilian propolis and its bioactive constituent, 3, 4, 5-tri-O-caffeoylquinic acid, Biol. Pharm. Bull., 10.1248/bpb.27.1797, 27, 11, 1797-1803, 27, 1797-1803, 2004.11.
189. K.Abesundara, T.Matsui, K.Matsumoto, a-Glucosidase inhibitory activity of some Sri Lanka plant extracts, One of which, Cassia auriculata, exerts a strong antihyperglycemic effect in rats comparable to the therapeutic drug acarbose, J.Agric. Food Chem., 10.1021/jf035330s, 52, 9, 2541-2545, 52, 2541-2544, 2004.05.
190. T.Matsui, M.Imamura, H.Oka, K.Osajima, K.Kimoto, T.Kawasaki, K.Matsumoto, Tissue distribution of antihypertensive dipeptide, Val-Tyr, after its single oral administration to spontaneously hypertensive rats, J.Peptide Sci., 10.1002/psc.568, 10, 9, 535-545, 10,535-545, 2004.01.
191. H.Oka, T.Matsui, T.Ueno, K.Matsumoto, T.Kawasaki, ACE inhibitory peptides can act as an inhibitor of vascular smooth muscle cell growth, J.Hypertension, 22, S68-S68, 22(suppl 1), S68, 2004.01.
192. T.Matsui, T.Kawasaki, Classification of natural ACE inhibitory peptides into C-/N-domain selective inhibitor, J.Hypertension, 22, S70-S70, 22(suppl. 1), S70, 2004.01.
193. T.Matsui, Material Food Interaction- How to evaluate food flavor deterioration by packaging-, International workshop on Advanced Packaging Technology" pp.163-202, 2004.01.
194. Physiological function and preparation of antihypertensive peptide, SVY, from 7S globulin..
195. Seiji Katano, Tomoyuki Oki, Yuka Matsuo, Kunitoshi Yoshihira, Yasuo Nara, Tomohiro Miki, Toshiro Matsui, Kiyoshi Matsumoto, Antihypertensive effect of alkaline protease hydrolysate of the pearl oyster Pinctada fucata martencii & separation and identification of angiotensin-I converting enzyme inhibitory peptides, Nippon Suisan Gakkaishi, 69, 6, 975-980, 2003.11, We hydrolyzed pearl oyster meat with alkaline protease treatment. We administered orally hydrolysate of pearl oyster meat to 8 week-old male SHR/Izm. As a result, the systolic blood pressure of SHR fell significantly from our last quotation of 202.4 mmHg to 180.0 mmHg in six hours. We controlled, isolated and identified four kinds of physiologically active peptides with low molecular weight and high level of ACE inhibition, and refined and identified them as Phe-Tyr, Ala-Trp, Val-Trp, and Gly-Trp with reversed phase chromatography. Among them, Ala-Trp was new and naturally occurring peptide. We estimated that the percentage contributing to ACE inhibition by those four peptides is 4.5%. Based on the study, we believe that promote pearl oyster meat as nutritious and functional food reduces blood pressure..
196. Antihypertensive effect of food containing sardine peptides in high-normal hypertensives amd hypertensives..
197. SOD-like activity of sardine muscle hydrolysate by alkaline protease..
198. Intestinal absorption behavior of bioactive peptides..
199. K.Nagao, N.Inoue, Y.-M.Wang. J.Hirata, Y.Shimada, T.Nagao, T.Matsui, and T.Yanagita, The 10trans,12cis isomer of conjugated linoleic acid suppress the development of hypertension in Otsuka Long-Evans Tokushima fatty rats, Biochem. Biophys. Res. Commun., 10.1016/S0006-291X(03)00929-X, 306, 1, 134-138, 306, 134-138, 2003.05.
200. T.Matsui, A.Hayashi, K.Tamaya, K.Matsumoto, T.Kawasaki, K.Murakami, and K.Kimoto, Depressor effect induced by dipeptide, Val-Tyr, in hypertensive transgenic mice is due, in part, to the suppression of human circulating renin-angiotensin system, Clin. Exp. Pharmacol. Physiol., 10.1046/j.1440-1681.2003.03824.x, 30, 4, 262-265, 30(4), 262-265, 2003.04.
201. N.Terahara, T.Matsui, K.Fukui, K.Matsugano, K.Sugita, and K.Matsumoto, Caffeoylsophorose in a red vinegar produced through fermentation with purple sweetpotato, J. Agric. Food Chem., 10.1021/jf026146u, 51, 9, 2539-2543, 51(9), 2539-2543, 2003.03.
202. K.Matsumoto, K.Takayama, J.M.Kanthi Abesundara, and T.Matsui, Assay of a-glucosidase inhibitory activity using flow-biosensor system, Anal. Chim. Acta, 10.1016/S0003-2670(02)01539-8, 479, 2, 135-141, 479, 135-141, 2003.02.
203. Hironori Moriyama, Yasuyuki Katayama, Hiroyuki Ukeda, Masayoshi Sawamura, Katsuhiro Osajima, Toshiro Matsui, Kiyoshi Matsumoto, Superoxide anion-scavenging activity of alkaline protease hydrolysate from sardine meat, Nippon Shokuhin Kagaku Kogaku Kaishi, 10.3136/nskkk.50.392, 50, 9, 392-398, 2003.01, Superoxide anion-scavenging activity (SOSA) of alkaline protease hydrolysate from sardine meat (A-1) was measured by colorimetry using water-soluble tetrazolium salt (WST-1). A-1 showed low activity with IC 50 value of 9.21 mg powder/ml. The hydrolysate was separated into F-1-F-6 on an ODS column. The most, active fraction (F-4) was fractionated by ion exchange chromatography on SP-Sephadex C-25 into three active fractions (1/SP-3/SP). The first fraction, 1/SP, showed the most potent activity (IC 50=4.11 mg powder/ml). By elution with a stepwise gradient of acetonitrile containing 0.1% TFA on Sep-pak plus C18 cartridge, A/SE (IC 50=2.12 mg powder/ml) and B/SE (IC50=7.14 mg powder/ml) were obtained from 1/SP. A/SE was extracted with water or 20% acetonitrile. A/ SE W, the water extract, showed high SOSA with an IC50 value of 0.51 mg powder/ml. The amino acid analysis of each active fraction indicated that five amino acid residues (Leu, Phe, Pro, Met, Tyr) played important roles in the activity. Moreover, it was suggested that the potent scavenger contained few histidine residue..
204. T.Matsui, S.Ebuchi, M.Kobayashi, K.Fukui, K.Sugita, N.Terahara, and K.Matsumoto, K.Matsumoto: Anti-hyperglycemic effect of diacylated anthocyanin derived from Ipomoea batatas cv. Ayamurasaki can be achieved through the a-glucosidase inhibitory action, J. Agric. Food Chem., 10.1021/jf025913m, 50, 25, 7244-7248, 50(25),7244-7248, 2002.12.
205. K.Matsumoto, K.Takemata, K.Takayama, J.M.Kanthi Abesundara, and T.Matsui, A novel method for the assay of a-glucosidase inhibitory activity using a multi-channel oxygen sensor, Anal. Sci., 10.2116/analsci.18.1315, 18, 12, 1315-1319, 18(12), 1315-1319, 2002.12.
206. Kiyoshi Matsumoto, Kayoko Takemata, Kiyofumi Takayama, Kanthi J M Abesundara, Toshiro Matsui, Hideo Katayama, A novel method for the assay of α-glucosidase inhibitory activity using a multi-channel oxygen sensor, Analytical Sciences, 18, 12, 1315-1319, 2002.12, The quantification of glucose by using a multi-channel dissolved oxygen (DO) meter (DOX96) with immobilized glucose oxidase (GOD) and mutarotase (MUT) was performed. An evaluation of the inhibitory activities for α-glucosidase (AGH) by modifying our batch-type pseudo-in vivo assay system [Oki et al.; Biol. Pharm. Bull., 2000, 232, 1084] was also performed using a DOX96. When 45 U/well GOD and 18.75 U/well MUT were immobilized on the surface of a gelatin membrane on the electrodes, the response shown by the decrease percent of DO (%) obtained with 8 electrode wells in the same row was linear with the glucose concentration up to 3.3 mM and a correlation coefficient larger than 0.9. To estimate the AGH inhibitory activity, AGH-immobilized Sepharose supports in the well of a silent screen plate were used. The IC50 values of acarbose and 1-deoxynojirimycin, a medicinal inhibitor for diabetes, were 0.70 ± 0.08 μM and 0.40 ± 0.13 μM, respectively, and coincided well with those by a pseudo-in vivo assay..
207. Safety and depressor effect of sardine peptide-drink in mild hypertensives, high-normal hypertensives, and normotensives..
208. Terukazu Kawasaki, Chen Jian Jun, Yoichi Fukushima, Kaori Kegai, Eiji Seki, Katsuhiro Osajima, Kazue Itoh, Toshiro Matsui, Kiyoshi Matsumoto, Antihypertensive effect and safety evaluation of vegetable drink with peptides derived from sardine protein hydrolysates on mild hypertensive, high-normal and normal blood pressure subjects, Fukuoka Acta Medica, 93, 10, 208-218, 2002.10, A randomized double-blind placebo-controlled study was conducted on 63 subjects to determine the antihypertensive effect of a vegetable drink in which sardine protein hydrolysates containing a dipeptide, Valyl-Tyrosine (VY), were incorporated. The subjects, consisting of people with mild hypertension, high-normal blood pressure and normal blood pressure, were randomly divided into test (male/female = 25/6, average age 50.1 +/- 10.4 years old) and control groups (26/6, 49.0 +/- 5.0). Each subject in the test group was given 195 g of the vegetable drink containing 0.5 g of sardine peptides (sardine protein hydrolysates) with 0.4 mg of VY (test drink) once a day for 13 weeks in a row, and subjects in the control group were given the same amount of the vegetable drink without sardine peptides (control drink) in the same manner. In the test group, 40 subjects with mild hypertension or high-normal blood pressure (130 mmHg < or = systolic blood pressure (SBP) < 160 mmHg and/or 80 mmHg < or = diastolic blood pressure (DBP) < 100 mmHg) showed a significant decrease in SBP, from 142.0 +/- 10.3 mmHg at the start of the test to 134.4 +/- 11.1 mmHg during the first week of the test period, after which similar values were seen throughout the test period (13 weeks). Compared to the control group, the difference in SBP from baseline was statistically significant in the test group throughout the intake period. DBP also decreased significantly from 88.0 +/- 7.9 mmHg at baseline to 83.5 +/- 8.6 mmHg after 13 weeks. In the control group, SBP and DBP were 140.8 +/- 8.4 mmHg and 90.5 +/- 6.6 mmHg respectively at the start of the test, and neither decreased during the test period. In subjects with normal blood pressure, neither those in the test group nor those in the control group showed a significant change in SBP and DBP during the test period. An excessive ingestion test was performed on 25 subjects with hypertension, mild hypertension, high-normal blood pressure, and normal blood pressure by giving 585 g (3 times the recommended amount of intake) of the test drink for 14 days in a row. As a result, a significant decrease of blood pressure was observed in the hypertension, mild hypertension and high-normal blood pressure groups, but no excessive decline in blood pressure or any side-effects were associated with any subjects during the test period. In the groups with normal blood pressure, the excessive ingestion of the test drink did not affect blood pressure. In these two studies, physical check-ups and biochemical analyses of blood and urine were also conducted in all subjects, and no abnormalities were observed. These results suggest that the test drink containing sardine protein hydrolysates exhibited the antihypertensive effect in only the subjects with mild hypertension or high-normal blood pressure. No adverse effects were observed in either hypertensive or normotensive subjects..
209. T.Matsui, K.Tamaya, E.Seki, K.Osajima, K.Matsumoto, and T.Kawasaki, Absorption of Val-Tyr with in vitro angiotensin I-converting enzyme inhibitory activity into the circulating blood system of mild hypertensive subjects., Biol. Pharmacol. Bull., 10.1248/bpb.25.1228, 25, 9, 1228-1230, 25(9), 1228-1230, 2002.09.
210. J.M.Kanthi Abesundara, M.Higuchi, T.Matsui, and K.Matsumoto, Evaluation of angiotensin I converting enzyme inhibitory activity by an FIA combined with biosensors., Anal. Sci., 10.2116/analsci.18.467, 18, 4, 467-468, 18(4), 467-468, 2002.08.
211. T.Matsui, K.Tamaya, E.Seki, K.Osajima, K.Matsumoto, and T.Kawasaki, Circulatory and localized angiotensin I-converting enzyme inhibitory effects of the sardine peptide, Val-Tyr., J. Hypertension, 20, S241-S241, 22(suppl.4), S241, 2002.06.
212. M.Imamura, T.Matsui, E.Seki, K.Osajima, K.Matsumoto, and T.Kawasaki, The relationship between rat age and the antihypertensive effect of the sardine peptide, Val-Tyr., J. Hypertension, 20, S241-S241, 22(suppl.4), S241, 2002.06.
213. T.Kawasaki, Y.Fukushima, J.J.Chen, K.Kegai, E.Seki, K.Osajima, K.Itoh, T.Matsui, and K.Matsumoto, Antihypertensive effect of drink containing peptides derived from sardine protein hydrolysate in mild hypertensive blood pressure subjects., J. Hypertension, 20, S332-S332, 22(suppl.4), S332, 2002.06.
214. Chun-Hui Li, T. Matsui, K. Matsumoto, R. Yamasaki, and T. Kawasaki, Latent production of angiotensin I-converting enzyme inhibitors from buckwheat protein., J. Peptide Sci., 10.1002/psc.387, 8, 6, 267-274, 8, 267-274, 2002.05.
215. T.Matsui, A.Yukiyoshi, S.Doi, H.Sugimoto, H.Yamada, and K.Matsumoto, Gastrointestinal enzyme production of bioactive peptides from royal jelly protein and their antihypertensive ability in SHR., J. Nutr. Biochem., 10.1016/S0955-2863(01)00198-X, 13, 2, 80-86, 13(2), 80-86, 2002.04.
216. Depressor effect of sardine peptide-drink in mild hypertensives and normotensives..
217. T.Matsui, K.Tamaya, E.Seki, K.Osajima, K.Matsumoto, and T.Kawasaki, Val-Tyr as a natural antihypertensive dipeptide can be absorbed into human circulatory blood system., Clin. Exp. Pharmacol. Physiol., 10.1046/j.1440-1681.2002.03628.x, 29, 3, 204-208, 29(3), 204-208, 2002.03.
218. T.Matsui, M.Kobayashi, S.Hayashida, and K.Matsumoto, Luteolin, a flavone, does not suppress postprandial glucose absorption through an inhibition of a-glucosidase action., Biosci. Biotechnol. Biochem., 66, 3, 689-692, 66(3), 689-692, 2002.03.
219. Toshiro Matsui, Mio Kobayashi, Sachiko Hayashida, Kiyoshi Matsumoto, Luteolin, a flavone, does not suppress postprandial glucose absorption through an inhibition of α-glucosidase action, Bioscience, Biotechnology and Biochemistry, 66, 3, 689-692, 2002.03, In order to clarify the postprandial glucose suppression via α-glucosidase (AGH) inhibitory action by natural compounds, flavonoids were examined in this study. Among the flavonoids (luteolin, kaempferol, chrysin, and galangin), luteolin showed the potent maltase inhibitory activity with the IC50 of 2.3 mM, while less inhibitions were observed against sucrase. In addition, the effects of maltase inhibition by flavonoids were observed in the descending order of potency of luteolin >kaempferol >chrysin >galangin. Apparently, the AGH inhibition power greatly increased with the replacement of hydroxyl groups at 3′ and 4′-position of the B-ring. However, the inhibitory power of luteolin was poorer than a therapeutic drug (acarbose: IC50; 430 nM). As a result of a single oral administration of maltose or sucrose (2 g/kg) in SD rats, no significant change in blood glucose level with the doses of 100 and 200 mg/kg of luteolin was observed. These findings strongly suggested that luteolin given at less than 200 mg/kg did not possess the ability to suppress the glucose production from carbohydrates through the inhibition of AGH action in the gut..
220. Mahmud Tareq Hassan Khan, T.Matsui, K.Matsumoto, and Shaila Jabbar, In vitro antihypertensive studies of some Bangladeshi plant extracts., Die Pharmazie, 56(11), 902-903, 2001.11.
221. T.Matsui, T.Ueda, T.Oki, K.Sugita, N.Terahara, and K.Matsumoto, a-Glucosidase inhibitory action of natural acylated anthocyanins. 1. Survey of natural pigments with potent inhibitory activity., J. Agric. Food Chem., 10.1021/jf001251u, 49, 4, 1948-1951, 49(4), 1948-1951, 2001.04.
222. T.Matsui, T.Ueda, T.Oki, K.Sugita, N.Terahara, and K.Matsumoto, a-Glucosidase inhibitory action of natural acylated anthocyanins. 2. a-Glucosidase inhibition by isolated acylated anthocyanins., J. Agric. Food Chem., 10.1021/jf0012502, 49, 4, 1952-1956, 49(4), 1952-1956, 2001.04.
223. M. T H Khan, Toshiro Matsui, Y. Matsumoto, S. Jabbar, In vitro ACE inhibitory effects of some Bangladeshi plant extracts, Die Pharmazie, 56, 11, 902-903, 2001.
224. T.Oki, T.Matsui, and K. Matsumoto, Evaluation of a-glucosidase inhibition by using an immobilized assay system., Biol. Pharm. Bull., 23(9), 1084-1087, 2000.09.
225. Y-H.Hwang, T.Matsui, T.Hanada, M.Shimoda, K.Matsumoto, and Y.Osajima, Desorption behavior of sorbed flavor compounds from packaging films with ethanol solution., J. Agric. Food Chem., 10.1021/jf991082h, 48, 9, 4310-4313, 48(9), 427-431, 2000.09.
226. T.Ishii, N.Koga, T.Matsui, K.Wada, Y.Osajima, and H.Ohta, Determination of flavonoid aglycones in plant food materials using high-performance liquid chromatography-phtodiode-array combined with electrochemical detection. Proceedings of 20th International Conference on Polyphenols, Proceedings of 20th International Conference on Polyphenols, Polyphenols Communications 2000, Freising-Weihenstephan (Germany), pp165-166, 2000.09.
227. T. Kawasaki, E. Seki, K. Osajima, M. Yoshida, K. Asada, Toshiro Matsui, Y. Osajima, Antihypertensive effect of valyl-tyrosine, a short chain peptide derived from sardine muscle hydrolyzate, on mild hypertensive subjects, Journal of Human Hypertension, 14, 8, 519-523, 2000.09, The present study was conducted to determine whether Valyl-Tyrosine (VY) has an antihypertensive effect on high-normal blood pressure and mild essential hypertension, as well as spontaneous hypertensive rats (SHR). A randomised double-blind placebo-controlled study was carried out on 29 volunteers. A 100-ml drink containing 3 mg of VY and a 100-ml placebo drink were prepared. The subjects were grouped as VY(16M/1F, 45.5 ± 3.2 years, 146.4 ± 2.3/90.5 ± 1.8 mm Hg) and the placebo (P) (11 M/1F, 48.8 ± 3.0 years, 145.5 ± 2.4/92.3 ± 1.8 mm Hg). At 3 weeks of the control (C) period, a VY- or P-drink was administered twice a day for 4 weeks in the experimental (E) period and during the 4-week recovery period, neither drink was given to either group. Blood pressure (BP) was measured every week in the morning in the sitting position. Blood specimens were taken on the last day of the C and E periods. In the VY-group, reduction in systolic (S) and diastolic (D) BP was 9.7 and 5.3 mm Hg (P < 0.001) at 1 week, and 9.3 and 5.2 mm Hg (P < 0.001) at 4 weeks, following the start of the E period, respectively. Neither SBP nor DBP changed in the P-group. BP in the VY-group increased gradually by the end of the recovery period. Plasma angiotensin (Ang) I and VY concentrations significantly increased while Ang II and aldosterone significantly decreased after VY administration in the VY-group. VY appeared to have a significant antihypertensive effect on mild hypertensive subjects via Ang I-converting enzyme inhibition, as well as SHR, but no adverse effects could be detected at all..
228. Deviation of desorption equation of flavors from plastic films by using compatibility theory..
229. T. Kawasaki, E. Seki, K. Osajima, M. Yoshida, K. Asada, T. Matsui, and Y. Osajima, Antihypertensive effect of Valyl-Tyrosine, a short chain peptide derived from sardine muscle hydrolyzate, on mild hypertensive subjects., J. Human Hypertens., 10.1038/sj.jhh.1001065, 14, 8, 519-523, 14, 519-523, 2000.08.
230. T.Matsui, K.Tamaya, K.Matsumoto, E.Seki, K.Osajima, and T.Kawasaki, The bioavailability of antihypertensive small peptide, Val-Tyr, in human., J. Hypertension, 18, S87-S87, 18(suppl.4), S87, 2000.08.
231. E.Seki, T.Kawasaki, K.Osajima, K.Tamaya, and T.Matsui, Antihypertensive effect of sardine peptide, Val-Tyr, in normotensive and hypertensive subjects., J. Hypertension, 18, S90-S90, 18(suppl.4), S90, 2000.08.
232. Y. Hama, T. Matsui, H. Hatae and T. Nakamura, Stereochemical assignment of conjugated carbonyls with a prostaglandin-like ring structure formed during autoxidation of linolenate., J. Jpn. Oil Chem., 49(8), 831-833, 2000.08.
233. Antihypertensive effect of sardine peptides in mild hypertensives and high-normal hypertensives..
234. T.Matsui, Chun-Hui Li, T. Tanaka, T. Maki, Y. Osajima, and K. Matsumoto, Depressor effect of wheat germ hydrolysate and its novel angiotensin I-converting enzyme inhibitory peptide, Ile-Val-Tyr, and the metabolism in rat and human plasma., Biol. Pharm. Bull., 23, 4, 427-431, 23(4), 427-431, 2000.04.
235. Toshiro Matsui, Chun Hui Li, Toshiaki Tanaka, Tetsuyoshi Maki, Yutaka Osajima, Kiyoshi Matsumoto, Depressor effect of wheat germ hydrolysate and its novel angiotensin I- converting enzyme inhibitory peptide, Ile-Val-Tyr, and the metabolism in rat and human plasma, Biological and Pharmaceutical Bulletin, 23, 4, 427-431, 2000.04, We report here the antihypertensive effect of wheat germ (WG) hydrolysate and its dominant peptide, Ile-Val-Tyr (IVY), with potent angiotensin I-converting enzyme (ACE) inhibitory activity. The toxicity test of AG50W fraction purified from the WG hydrolysate and IVY in tidy mice revealed that 1 week median lethal concentrations of AG fraction and IVY were less than 100 and 10 mg/kg, respectively. As a result of an intravenous administration test of both inhibitors in spontaneously hypertensive rat (SHR), the mean arterial blood pressure (MAP) significantly decreased with the dose; the MAP reduction of 10.3 and 19.2 mmHg was observed at a dose of 50 mg/kg of AG fraction and 5 mg/kg of IVY, respectively. In addition to this behavior, the MAP gradually decreased after the 5 mg/kg of IVY injection (time to give a maximum reduction; 8 min), and the reduction was held for 20 min. By using rat and human plasma, IVY was found to be metabolized by the action of aminopeptidase in plasma to form a subsequent ACE inhibitor, Val- Tyr (VY). Thus, the intake of IVY as a physiologically functional food would serve in the lowering of blood pressure (BP) by the combined depressor effect of itself and its metabolite after the absorption..
236. Toshiro Matsui, Kiyoshi Matsumoto, Physiological functions of food components - Analytical evaluation of complex functional food matrices (Review), Bunseki Kagaku, 10.2116/bunsekikagaku.49.477, 49, 7, 477-491, 2000.01, The development of an analytical evaluation of the physiological function of food components is reviewed. In vitro and/or in vivo evaluation methods of the prophylaxes in hypertensive and diabetic diseases by food components are extensively discussed. Other food functionalities used to maintain homeostasis are also discussed..
237. T. Oki, Toshiro Matsui, K. Matsumoto, Evaluation of α-glucosidase inhibition by using an immobilized assay system, Biological and Pharmaceutical Bulletin, 23, 9, 1084-1087, 2000, The inhibitory effects of natural and synthetic inhibitors on the intestinal membrane-bound hydrolase, α-glucosidase (AGH), were evaluated by using an immobilized cyanogen bromide-activated Sepharose 4B support. Immobilized AGH (iAGH) inhibition study by synthetic inhibitors (acarbose and voglibose) revealed that the magnitude of inhibition differed from that in the free AGH (fAGH) study: IC50 value of acarbose in iAGH-maltase assay system, 340 - 430 nM; fAGH, 11 nM. iAGH-maltase inhibition by both inhibitors was influenced by blocking reagents with different functional groups (COOH, OH, CH3, and NH2 groups). On the other hand, significant iAGH-sucrase inhibitory activity was observed only when using the negatively charged support induced by 0.1 M β-alanine. The K(m) values obtained in the iAGH assay system were similar to those from the fAGH method. With natural inhibitors, the iAGH-sucrase inhibitory activity of D-xylose, with in vivo glucose suppression, increased twice compared to that in fAGH. Green tea extract gave almost the same inhibition for both AGH assay systems..
238. Preparation and isolation of angiotensin I-converting enzyme inhibitory substrates from chiken essence hydrolysate..
239. Antihypertensive effect of sardine peptides and Val-Tyr - antihypertensive effect of the peptides in spontaneously hypertensive rats-.
240. T.Matsui, K.Tamaya, K.Matsumoto, Y.Osajima, K.Uezono, and T.Kawasaki, Plasma concentrations of angiotensin metabolites in young male normotensive and mild hypertensive subjects., Hypertens. Res., 10.1291/hypres.22.273, 22, 4, 273-277, 22(4), 273-277, 1999.08.
241. T.Matsui, K.Tamaya, T.Kawasaki, and Y.Osajima, Determination of angiotensin metabolites in human plasma by fluorimetric high-performance liquid chromatography using a heart-cut column-switching technique., J. Chromatogr.B, 10.1016/S0378-4347(99)00128-0, 729, 1-2, 89-95, 729, 89-95, 1999.07.
242. T.Matsui, C. -H. Li, and Y.Osajima, Preparation and characterization of novel bioactive peptides responsible for angiotensin I-converting enzyme inhibition from wheat germ., J. Peptide Sci., 10.1002/(SICI)1099-1387(199907)5:7<289::AID-PSC196>3.0.CO;2-6, 5, 7, 289-297, 5, 289-297, 1999.05.
243. P.Pfnuer, T.Matsui, W.Grosch, H.Guth, and P.Schieberle, Development of a stable isotope dilution assay for the quantification of 5-methyl-(E)-2-heptene-4-one: Application to hazelnut oils and hazelnuts., J. Agric. Food Chem., 10.1021/jf9810214, 47, 5, 2044-2047, 47(5), 2044-2047, 1999.05.
244. Toshiro Matsui, Tomoyuki Oki, Yutaka Osajima, Isolation and identification of peptidic α-glucosidase inhibitors derived from sardine muscle hydrolyzate, Zeitschrift fur Naturforschung - Section C Journal of Biosciences, 54, 3-4, 259-263, 1999.03, We report here the isolation of α-glucosidase (AGH) inhibitory peptides derived from sardine muscle hydrolyzate, which was prepared by digestion with Bacillus licheniformis alkaline protease. As a result of reversed-phase HPLC purification, two AGH inhibitory peptides were isolated from a DEAE-Sephadex A-25 column eluate. The peptides were identified as follows: Val-Trp (IC50 = 22.6 mM) and Try-Tyr-Pro-Leu (IC50 ± 3.7 mM). AGH inhibitory studies of Try-Tyr-Pro-Leu and its derivatives demonstrated the importance of the tripeptide chain length as well as the hydrophobic aromatic amino acid tyrosine at the N-terminus, aliphatic amino acids at the C-terminus, as well as an amide proton from the peptide chain at the middle position of the tri-peptide to develop AGH inhibition activity..
245. T.Matsui, T. Oki, and Y.Osajima, Isolation and identification of peptidic a-glucosidase inhibitors derived from sardine mucle hydrolyzate., Z. Naturforsch., 54, 3-4, 259-263, 54C, 259-263, 1999.02.
246. T.Oki, T.Matsui, and Y.Osajima, Inhibitory effect of a-glucosidase inhibitors varies according to its origin., J. Agric. Food Chem., 10.1021/jf980788t, 47, 2, 550-553, 47(2), 550-553, 1999.02.
247. T.Oki, K.Matsumoto, T.Matsui, and Y.Osajima, Change in catalytic property of trypsin immobilized on support activated with glutaraldehyde in lower protogenic solvent., Food Sci. Technol. Res., 5(1), 13-17, 1999.01.
248. Tomoyuki Oki, Kiyoshi Matsumoto, Toshiro Matsui, Yutaka Osajima, Change in Catalytic Property of Trypsin Immobilized on Support Activated with Glutaraldehyde in Lower Protogenic Solvent, Food Science and Technology Research, 10.3136/fstr.5.13, 5, 1, 13-17, 1999, A variety of glutaraldehyde (GA) activated-aminopropyl controlled pore glass supports were prepared in lower protogenic solvents (methanol, ethanol, and n-propanol). When trypsin was used as the ligand, the amount of trypsin immobilized on them decreased in the order of water, methanol, ethanol, and n-propanol; the maximal reduction of 22% was observed in n-propanol versus that in water. The Michaelis constants of the trypsins immobilized on the support activated with GA in alcohols, especially ethanol and propanol, were smaller than that in water, and the minimum Km value of 1.84X10-1 mM was obtained in propanol (4.29X10-1 mM in water). During the reaction of GA with 2-aminoethanol, the amount of the aldehyde group from GA being capable of reacting with 2-aminoethanol significantly decreased when the reaction was done in n-propanol (0.18 mmol/assay volume, cf. in water; 035 mmol/assay volume). The gel permeation chromatography (GPC) measurement of the GA complex, glycine-GA-phenetylamine, also revealed the suppression of the GA self-polymerization in the lower protogenic alcohol as a support activating solvent..
249. Toshiro Matsui, Kei Tamaya, Kiyoshi Matsumoto, Yutaka Osajima, Keiko Uezono, Terukazu Kawasaki, Plasma concentrations of angiotensin metabolites in young male normotensive and mild hypertensive subjects, Hypertension Research, 22, 4, 273-277, 1999, The plasma concentrations of angiotensin (Ang) I, Ang II, and their metabolites (Ang (3-8), (4-8), (5-8), and (3-4)) following in vitro ACE inhibitory activity were examined in young male normotensive (NT) (n = 7), and mild hypertensive (HT) volunteers in = 6). There were no differences in supine plasma levels of Ang I, Ang II, and Ang (5-8) between the NT and HT groups: Ang I, 304 ± 43 fmol/ml vs. 293 ± 15 fmol/ml; Ang II, 32 ± 6 fmol/ml vs. 43 ± 10 fmol/ml; Ang (5-8), 176 ± 22 fmol/ml vs. 133 ± 32 fmol/ml. In addition, there were no significant differences between groups in any of these Ang levels when measured after standing for 60 min. However, the HT group showed significantly reduced supine and upright plasma Ang (3-8) and Ang (3-4) levels as compared to the NT group. In particular, the supine plasma level of Ang (3-4) (71 ± 13 fmol/ml-plasma) in the HT group was significantly (1/3-fold) lower than that in the NT group (197 ± 35 fmol/ml-plasma). An inverse correlation between the plasma level of Ang (3-4) and the upright systolic blood pressure (r = -0.627, p < 0.02, n = 13) was observed, indicating that the metabolism of Ang (3-4) might have been associated with the change in blood pressure..
250. N.Terahara, K. Toki, N. Saito, T. Honda, T.Matsui, and Y.Osajima, Eight new anthocyanins, Ternatins C1-C5 snd D3 and preternatins A3 and C4 from young Clitoria ternatea flowers., J. Nat. Prod., 61(11), 1361-1367, 1998.11.
251. Norihiko Terahara, Kenjiro Toki, Norio Saito, Toshio Honda, Toshiro Matsui, Yutaka Osajima, Eight new anthocyanins, ternatins C1-C5 and D3 and preternatins A3 and C4 from young Clitoria ternatea flowers, Journal of Natural Products, 10.1021/np980160c, 61, 11, 1361-1367, 1998.11, Eight new anthocyanins 1-8 (ternatins C1, C2, C3, C4, C5, and D3 and preternatins A3 and C4) were isolated from Clitoria ternatea flowers. By the application of chemical, UV-vis, and FABMS methods, the structures of 1-6 were postulated as delphinidin 3-malonylglucoside having 3'-GCGC-5'-G, 3'- GCGCG-5'-G, 3'-GC-5'-G, 3'-GCG-5'-G, 3'-G-5'-G, and 3'-GC-5'-GC, and compounds 7 and 8 as delphinidin 3-glucoside having 3'-GCG-5'-GCG and 3'- GCG-5'-G as side chains, respectively, in which Dp is delphinidin, G is D- glucose, and C is p-coumaric acid. The structures of the compounds 1, 3-5, and 7 were established completely by additional NMR methods..
252. T.Kawasaki, K.Osajima, E.Seki, M.Yoshida, K.Asada, T.Matsui, and Y.Osajima, Antihypertensive effect of Val-Tyr, a short chain peptide derived from sardine muscle hydrolyzate, on hypertensives., J. Hypertension, 16, S25-S25, 16(suppl.2), S25, 1998.06.
253. T.Matsui, Y.Osajima, K.Uezono, and T.Kawasaki, Metabolism of endogenous Val-Tyr with antihypertensive effect in human plasma., J. Hypertension, 16, S138-S138, 16(suppl.2), S138, 1998.06.
254. Antihypertensive effect of sardine peptides in mild hypertensive subjects..
255. T.Matsui, H.Guth, and W.Grosch, A comparative study of potent odorants in peanut, hazelnut, and pumpkin seed oils on the basis of aroma extract dilution analysis (AEDA) and gas chromatography-olfactometry of headspace samples(GCOH), Fett/Lipid, 100, 2, 51-56, 100(2), 51-56, 1998.02.
256. Kiyoshi Matsumoto, Tetsuro Yoshimaru, Toshiro Matsui, Yutaka Osajima, Enzymatic degradation of ovalbumin by various proteases, Journal of the Faculty of Agriculture, Kyushu University, 41, 3-4, 239-245, 1997.03, An investigation was made of the enzymatic hydrolysis of ovalbumin (OVA), a major allergen in egg white, by various acid and alkaline proteases. Protease YP-SS (acid protease) from Aspergillus niger and alcalase (alkaline protease) from Bacillus licheniformis were found to be useful for the degradation of OVA, respectively. OVA was almost totally hydrolyzed within 15 hr at 37°C by alcalase. Alcalase acted rapidly to hydrolyze OVA, with about 90% of OVA being hydrolyzed within 30 min., the reaction then proceeded more slowly. The antigenicity of the OVA hydrolysate was investigated with IgG raised in rats against OVA and it was apparent that the antigenicity had been almost completely destroyed..
257. Toshiro Matsui, Hiroshi Matsufuji, Terukazu Kawasaki, Yutaka Osajima, Determination of endogenous peptides with in vitro ACE inhibitory activity in normotensive human plasma by the fluorometric HPLC method, Bioscience, Biotechnology and Biochemistry, 10.1271/bbb.61.1052, 61, 6, 1052-1054, 1997.01, An in vitro degradation test of angiotensin (ANG) II or III in normotensive supine human plasma from 9 healthy male subjects confirmed the production of smaller ANG metabolites with angiotensin I-converting enzyme inhibitory activity. These metabolites were identified as ANG (3–8), ANG (4–8), ANG (5–8), and ANG (3–4), whose respective peptide concentrations were determined by our proposed naphthalene-2, 3-dialdehyde (NDA)-HPLC method to be 64 ±9, 39 ±5, 176 ± 22, and 197 ± 35 fmol/ml of plasma. Pediococcus sp. ISK-1 isolated in our laboratory from well-aged Nukadoko, produces a bacteriocin which has a unique antimicrobial spectrum among pediocins. The bacteriocin was stable at acidic pH, and more than 60% of the antimicrobial activity still remained even after being autoclaved at 121°C for 20min in the pH range of 3 to 8. This is the first report dealing with a bacteriocin produced by lactic acid bacteria isolated from Nukadoko..
258. Toshiro Matsui, Hiroshi Matsufuji, Kei Tamaya, Terukazu Kawasaki, Yutaka Osajima, Metabolic behavior of angiotensins in normotensive human plasma in the supine and upright postures, Bioscience, Biotechnology and Biochemistry, 10.1271/bbb.61.1814, 61, 11, 1814-1818, 1997.01, The effect of activating the renin-angiotensin system on the metabolism of angiotensins (ANGs) in normotensive human plasma was investigated. In normotensive supine human plasma, four peptides with in vitro angiotensin I-converting enzyme (ACE) inhibitory activity which correspond to the sequence of ANG (3–8), ANG (4–8), ANG (5–8), and ANG (3–4) existed at a concentration of > 39fmol/ml of plasma. When activating the renin activity by keeping upright in posture for 60min, ANG II and the four peptides significantly increased as compared with the levels in the supine posture, except for ANG I. In particular, Val-Tyr corresponding to ANG (3–4) in the upright posture was about 4-fold more than the value in the supine posture, and was predominantly present (447 fmol/ml of plasma) as well as ANG I. As a result of in vitro degradation tests on ANGs, ANG (3–4) was produced from ANG I, and not from ANG II, III or (3–8), during the 30-min incubation..
259. Toshiro Matsui, Tomoyuki Oki, Kiyoshi Matsumoto, Yutaka Osajima, Preparation of glutaraldehyde cross-linked complex from support, Bioscience, Biotechnology and Biochemistry, 10.1271/bbb.61.893, 61, 5, 893-895, 1997.01, A glutaraldehyde (GA) spacer complex on enzyme immobilization was cleaved from the support introduced Nα -9-fluorenylmethyl-oxycarbonylglycine. By the 1H-NMR spectroscopic measurement of the desired complex, glycine-GA-phenethylamine (GGP), GA was thought to be involved in enzyme immobilization as a heteropolymer with the molecular weight range of about 600 to 1300..
260. Toshiro Matsui, Toshiaki Nakao, Mitsuya Shimoda, Yutaka Osajima, Fumio Mori, Removal of oxygen in food packaging by disodium ascorbic acid / PVC coated cap, Nippon Shokuhin Kagaku Kogaku Kaishi, 44, 5, 361-366, 1997, In order to remove oxygen from food packaging, disodium ascorbic acid/polyvinyl chloride (AsN/PVC) was coated onto its cap. When a container with a AsN/PVC cap containing 100 mg of AsN was used for a storage experiment, the oxygen in it was effectively removed more than 50% from the headspace during 30 days' storage at 35°C. The consumption behavior of oxygen was found to depend on the headspace volume of the container; for the container with 31 ml of headspace volume the O 2 consumption ratio per volume was 1.4-fold higher than that for the container with 77.5 ml of the volume. Also, the O 2 consumption lowered with lower storage temperature. By using the AsN/PVC cap, flavors in the container were successfully preserved from the oxidative deterioration; the residual ratios for n-hexanal, n-heptanal, d-limonene, and α-pinene with the AsN/PVC cap were 65.0%, 48.9%. 39.1% and 41.0%, respectively after 42 days' storage. In addition, when the cap was used for a liquid food container with 46.5 ml of headspace volume, more than 85% of dissolved oxygen was found to be removed from 0.1% arabic gum solution within 25 days' storage..
261. Norihiko Terahara, Masahiro Oda, Toshiro Matsui, Yutaka Osajima, Norio Saito, Kenjiro Toki, Toshio Honda, Five new anthocyanins, ternatins A3, B4, B3, B2, and D2, from Clitoria ternatea flowers, Journal of Natural Products, 10.1021/np960050a, 59, 2, 139-144, 1996.02, Five new ternatins 1-5 have been isolated from Clitoria ternatea flowers, and the structures have been determined by chemical and spectroscopic methods as delphinidin 3-malonylG having 3'-GCG-5'-GCG, 3'- GCG-5'-GC, 3'-GCGCG-5'-GC, 3'-GCGC-5'-GCG, and 3'-GCGC-5'-GC side chains, respectively, in which G is p-glucose and C is p-coumaric acid. Pigment 1 had symmetric 3',5'-side chains. Compounds 3 and 4 are structural isomers. These ternatins were shown to form an intramolecular stacking between the aglycon ring and the 3',5'-side chains in solution..
262. Toshiro Matsui, Chiho Yoshimoto, Katsuhiro Osajima, Tomoyuki Oki, Yutaka Osajima, In vitro survey of α–glucosidase inhibitory food components, Bioscience, Biotechnology and Biochemistry, 10.1271/bbb.60.2019, 60, 12, 2019-2022, 1996.01, A survey of food components with α-glucosidase (AGH) inhibitory activity was conducted to identify a prophylactic effect for diabetes in food. Sardine muscle hydrolyzed by alkaline protease showed potent activity (IC50 = 48.7mg/ml) as well as green and oolong teas (IC50 = 11.1 and 11.3mg/ml, respectively). Furthermore, hydrolyzates prepared by various proteases gave differing AGH inhibitory activity. DEAE-Sephadex chromatography of the alkaline protease hydrolyzate eluted potent AGH inhibitors (IC50 = 15.6mg/ml) with a 50 mM phosphate buffer (pH 7.0) containing 0.3 m NaCl, and their subsequent separation by HPLC in an ODS column showed that there were some inhibitors possessing primary amino groups. This indicates that they would have been high anionic and peptidic compounds..
263. Eiji Seki, Katsuhiro Osajima, Hiroshi Matsufuji, Toshiro Matsui, Yutaka Osajima, Angiotensin I converting enzyme inhibitory peptides generated from oligopeptides by intestinal mucosa peptidases, Nippon Nogeikagaku Kaishi, 70, 1, 21-27, 1996, Peptide hydrolases were prepared from porcine small intestinal mucosa and their properties were examined using the following peptide substrates : Arg-Lys-Glu-Val-Tyr, Arg-Lys-Asp-Val-Tyr, Val-Tyr-Val, ACE inhibitory dipeptides, and other dipeptides. Peptide hydrolases hydrolyzed all the peptides above cited, and released the amino acid from the NH2-terminus of the tri and pentapeptides. Ile-His, Gly-Pro, Phe-Pro, His-Pro, Pro-Phe, Asp-Glu, Asp-Asp, Glu-Glu, Glu-Asp, Gly-Sar, Pro-Gly, and Val-Tyr showed resistance to dipeptidases, but, Gly-Trp, Met-Phe, and Arg-Tyr, with ACE inhibitory activity were rapidly hydrolyzed. Glu-Val-Tyr and Asp-Val-Tyr rapidly released Glu and Asp, respectively, as tri and aminopeptidases. The results suggested that the primary structure of dipeptides, tripeptides, and oligopeptides are involved in ACE activity. Val-Tyr is a major ACE inhibitory peptide derived from sardines. Also, oligopeptides having Val-Tyr at the COOH-terminus were rapidly hydrolyzed by peptide hydrolases including tri and aminopeptidases from porcine small intestinal mucosa, but, resistant Val-Tyr had a potent ACE inhibitory activity..
264. Eiji Seki, Katsuhiro Osajima, Hiroshi Matsufuji, Toshiro Matsui, Yutaka Osajima, Angiotensin I converting enzyme inhibitory activity of the short chain peptides derived from various food proteins, Nippon Shokuhin Kagaku Kogaku Kaishi, 10.3136/nskkk.43.839, 43, 7, 839-840, 1996, Twelve kinds of food proteins were hydrolyzed by Bacillus licheniformis alkaline proteases to form peptides of average chain length, 2.26-4.02. The hydrolyzates from shrimp, crab and sardine contained many di- and tri-residues whose angiotensin I converting enzyme (ACE) inhibitory activities were stronger than that of the hydrolyzates from soy bean, hair tail, oyster, beef, chicken, pork, chicken egg yolk, chicken egg white and casein. The IC50 was 0.072, 0.075 and 0.076 mg protein/ml, respectively. Hydrophobic amino acid residues situated in the interior of protein molecules were exposed by fragmentation with proteases, and the peptides containing hydrophobic amino acid residues were found in aqueous solution. The peptide from casein showed the highest hydrophobicity and whose taste was the most bitter..
265. Eiji Seki, Katsuhiro Osajima, Hiroshi Matsufuji, Toshiro Matsui, Yutaka Osajima, Effect of Val-Tyr on degradation of bradykinin and angiotensin I, Nippon Shokuhin Kagaku Kogaku Kaishi, 43, 11, 1229-12360, 1996, Bradykinin was converted rapidly into the fragment 1-8 by kininase I when incubated with human plasma. Kininase II inactivated bradykinin by splitting the Pro7-Phe8 and the Phe5-Ser6 bonds in it. ACE inhibitory peptide Val-Tyr and captopril did not inhibit the conversion of bradykinin in human plasma into the fragments 1-8, 1-7 and 1-5. Bradykinin was converted into the fragments 1-7 and 1-5 by dipeptidyl peptidase activity of ACE. Captopril inhibited degradation of bradykinin by dipeptidyl peptidase activity of ACE, but Val-Tyr did not inhibit..
266. Eiji Seki, Katsuhiro Osajima, Hiroshi Matsufuji, Toshiro Matsui, Yutaka Osajima, Quantitative analysis of digestion resistant ACE inhibitory dipeptides by small intestinal mucosa, Nippon Shokuhin Kagaku Kogaku Kaishi, 10.3136/nskkk.43.967, 43, 8, 967-969, 1996, The short chain peptides derived from sardines were incubated for 120 min with an extract of porcine small intestinal mucosa. Digestion-resistant dipeptides found in the digest, Val-Tyr, Val-Trp, Ile-Tyr and Ile-Trp, inhibited angiotensin I converting enzyme (ACE). Amounts of the four dipeptides isolated from the digest using a Sep-pak C-18 cartridge column and three steps of high-performance liquid chromatography, were 85.88, 21.87, 10.69 and 6.51 mg/100 g peptides, respectively, and the contribution of four peptides to total ACE inhibitory activity was 10.5%. It was confirmed that ACE inhibitory dipeptides were present in the digest of the short chain peptides..
267. Toshiro Matsui, Toshiaki Nakao, Masaomi Fukamachi, Noriko Shikada, Mitsuya Shimoda, Yutaka Osajima, Removal of dissolved oxygen by immobilized ascorbate oxidase onto a packaging film, Nippon Shokuhin Kagaku Kogaku Kaishi, 10.3136/nskkk.43.362, 43, 4, 362-367, 1996, In order to remove dissolved oxygen from liquid food, ascorbate oxidase (AO) was covalently immobilized onto ethylene-vinyl alcohol copolymer (EVOH) film. Maximal activity was observed at pH 6.0, 30°C (1.14 mU/cm2). The immobilized AO still retained a higher residual activity than free AO under practical conditions ; at pH 4.0 corresponding to citrus juice, 10°C and 60°C, the residual activities were 47.8%, 91.3%, and 49.4% whereas those of free AO were 3.1%, 63.3% and 0%, respectively. When the AO immobilized EVOH film was directly in contact with 2.5 mM L-ascorbic acid in 10 mM citrate buffer solution (pH 4.0), more than 85% of dissolved oxygen was removed within 4h. In addition, flavors (d-limonene, linalool, and citral) in the solution were successfully preserved from the oxidative deteriorations ; for d-limonene, the residual ratio (71.6%) with AO immobilized EVOH film was 2.5-fold that with non-immobilized one (29.0%) after 28 days' storage..
268. Eiji Seki, Katsuhiro Osajima, Hiroshi Matsufuji, Toshiro Matsui, Yutaka Osajima, Resistance to gastrointestinal proteases of the short chain peptides having reductive effect in blood pressure, Nippon Shokuhin Kagaku Kogaku Kaishi, 10.3136/nskkk.43.520, 43, 5, 520-525, 1996, The peptides with average molecular weight 315 were prepared from sardine proteins by Bacillus licheniformis alkaline proteases. The short chain peptides had no bitter taste and little fish flavor. The short chain peptides showed the potent angiotensin I-converting enzyme (ACE) inhibitory activity, which was high resistance to the hydrolysis by any digestive proteases. ACE inhibitory activity of short chain peptides didn't change by the pig intestinal fluid after pepsin digestion. Compared with the long chain peptides in sardine muscle hydrolyzate prepared by digestive proteases, inhibitory activities of various digest were weaker than that of the short chain peptides derived from alkaline proteases hydrolyzate. The short chain peptides were assayed in spontaneously hypertensive rats and found to reduce on blood pressure..
269. Masaomi Fukamachi, Toshiro Matsui, Yoon Hee Hwang, Mitsuya Shimoda, Yutaka Osajima, Sorption Behavior of Flavor Compounds into Packaging Films from Ethanol Solution, Journal of Agricultural and Food Chemistry, 10.1021/jf950707i, 44, 9, 2810-2813, 1996, The sorption of flavor compounds into low-density polyethylene (LDPE) and ethylene-vinyl alcohol copolymer (EVOH) films was greatly influenced by ethanol concentration, and maximal sorptions were observed at 5-10% (v/v) ethanol for LDPE and 10-20% (v/v) ethanol for EVOH. The sorptions of ethyl hexanoate, octanal, and octanol into LDPE film were ∼1.7, 16.5, and 2.5 times higher than those in the 0% (v/v) ethanol solution, respectively (for EVOH film, the sorption increments of these compounds were ∼6.2, 3.5, and 4.1 times, respectively). To better understand this phenomenon, the solvent properties of ethanol solutions were investigated. The dielectric constants were roughly unchanged in the range 5-15% (v/v) ethanol. According to the results obtained by 1H NMR measurement, in which the difference in proton chemical shift from water-d (HDO) and ethyl alcohol-d (EtOD) became maximum at 23% (v/v) ethanol solution, the structural change of water induced by the addition of ethanol would be great up to 23% (v/v) ethanol. These results accurately reflected the sorption behavior. Therefore, the specific sorption behavior of flavor compounds from an ethanol solution would be brought about by the heterogeneous water-ethanol structure..
270. Hiroshi Matsufuji, Toshiro Matsui, Satoko Ohshige, Terukazu Kawasaki, Katsuhiro Osajima, Yutaka Osajima, Antihypertensive Effects of Angiotensin Fragments in SHR, Bioscience, Biotechnology and Biochemistry, 10.1271/bbb.59.1398, 59, 8, 1398-1401, 1995.01, When angiotensin fragments, Val-Tyr and Angiotensin III (ANG III), with potent ACE inhibitory activity were intravenously administered to spontaneously hypertensive rat (SHR), a significant reduction of diastolic blood pressure was observed. After incubation of ANG III with SHR plasma, four fragments with ACE inhibitory activity, Val-Tyr (ANG (3-4)) (IC50=26.0μM), Ile-His-Pro-Phe (ANG (5-8)) (11.6μM), Tyr-Ile-His-Pro-Phe (ANG (4-8)) (457.5μM), and Val-Tyr-Ile-His-Pro-Phe (ANG (3-8)) (6.55μM), were confirmed to generate in SHR plasma. Compared the metabolic behavior of ANG II in SHR plasma with that in normotensive Wistar plasma, the initial degradation rate (3.07nmol/ml/min) in Wistar plasma was about 2-fold higher than that in the SHR one (1.75nmol/ml/min)..
271. Hiroshi Matsufuji, Toshiro Matsui, Tomoyuki Oki, Yutaka Osajima, Terukazu Kawasaki, Fluorometric determination of angiotensins in human plasma derivatized with 2,3-naphthalenedialdehyde, Bunseki Kagaku, 10.2116/bunsekikagaku.44.783, 44, 10, 783-788, 1995, A fluorometric determination method for angiotensins (ANG I, II, III) in human plasma was developed with 2,3-naphthalenedialdehyde (NDA). Human plasma (10 ml) ultrafiltered with a Molucut L (< M.W. 5000) was put directly on a reversed-phase column for HPLC with an UV detector. The fractions containing each angiotensin were derivatized with 0.1 mM NDA in the presence of cyanide for 60 min at ambient temperature. The derivatized angiotensin (NDA-ANG) was injected onto the HPLC system with a fluorometric detector. Excitation and emission wavelengths were set at 420 nm and 490 nm, respectively. The peak areas of NDA-ANG were linearly related with the amount of angiotensin applied, and were highly reproducible (3.5%, n=5). The concentrations of ANG I, II and III in plasma, calculated from the respective calibration curve, were 315.8 pg/ml, 19.2pg/ml and <1.3pg/ml, respectively. The concentration of ANG II obtained by this fluorometric method coincided with that (22.6 pg/ml) by radioimmunoassay..
272. Eiji Seki, Katsuhiro Osajima, Hiroshi Matsufuji, Toshiro Matsui, Yutaka Osajima, Immunologially Applicability for Foods of Short Chain Peptides Derived from Sardines, Nippon Nogeikagaku Kaishi, 10.1271/nogeikagaku1924.69.1171, 69, 9, 1171-1174, 1995, Short chain peptides with the average chain length of 2.67 prepared from sardine protein have reductive effects on blood pressure, and are expected to be a physiologically functional foodstuff. The short chain peptides were found to be negative in the active systemic anaphylaxis (ASA) test in guinea pigs sensitized by oral administrations of the short chain peptides. Negative results were also obtained in the homologous passive cutaneous anaphylaxis (PCA) test, which was done against sera from guinea pigs sensitized by oral administration of the short chain peptides. The short chain peptides have a potent angiotensin I converting enzyme (ACE) inhibitory activity, this enzyme catalyses the activation of angijotensin II and inactivation of bradykinin. The bradykinin is able to stimulate macrophages, to enhance lymphocyte migration, and to increase secretion of lymphokines. The short chain peptides favor bradykinin activity, which showed concentrated pigment coloration in the PCA test by subcutaneous sensitization. These results suggest that the short chain peptides have no antigenicity by oral administration, and are usable in foods..
273. Eiji Seki, Katsuhiro Osajima, Hiroshi Matsufuji, Toshiro Matsui, Yutaka Osajima, Val-tyr, an Angiotensin I Converting Enzyme Inhibitor from Sardines that have Resistance to Gastrointestinal Proteases, Nippon Nogeikagaku Kaishi, 10.1271/nogeikagaku1924.69.1013, 69, 8, 1013-1020, 1995, The NH2-terminal residue of a dipeptide is an important determinant of the resistance to peptidases of porcine small mucosa. NH2-terminal Val or Ile, and COOH-terminal Trp or Tyr dipeptides had higher angiotensin I converting enzyme(ACE)inhibitory activity and digestive resistance than other dipeptides. We defined Val-Tyr as a main inhibitor in alkaline protease hydrolyzates from sardines. Attempts to isolate and measurement of Val-Tyr were done from the short chain peptides that reduced blood pressure. The content of Val-Tyr was 51 mg per 100 g of the short chain peptides, represented 1.3% of the total ACE inhibitory activity of the short chain peptides. Isolated Val-Tyr was resistant to gastrointestinal proteases. The primary structures of fragments formed from Arg-Val-Tyr by digestive proteases were considerably different, and it was confirmed that the main peptide, Val-Tyr, was formed by intestinal proteases after digestion. The content of Val-Tyr formed from the short chain peptides by intestinal proteases after digestion was less than 10 percent of the original..
274. Toshiro Matsui, Masaomi Fukamachi, Mitsuya Shimoda, Yutaka Osajima, Derivation of Thermodynamic Sorption Equation of Flavors with Packaging Films. 1, Journal of Agricultural and Food Chemistry, 10.1021/jf00048a045, 42, 12, 2889-2892, 1994.12, The sorption equation of flavors with packaging film to extend for various flavors and polymers was derived by improving the proposed δc concept. On the basis of the findings that the sorptions depend on both the δc values between film and flavors with similar chemical potential and their molar heat of vaporization (ΔHvap), the following thermodynamic sorption equation was derived: S = So exp γ[Vvv2c2)/RT]. For aqueous phase the plots of In S vs the term of the equation gave an adequate but insufficient relationship (r = 0.802), resulting from the influence of any interaction force from solution on the magnitudes of physical adsorption and condensation of flavors on film surface. On the other hand, for vapor phase the same plots gave a quite sufficient correlation (r = 0.967). Therefore, in the prediction of the sorption behaviors for vapor phase the derived sorption equation may be more useful and effective..
275. Masaomi Fukamachi, Toshiro Matsui, Mitsuya Shimoda, Yutaka Osajima, Derivation of Thermodynamic Sorption Equation of Flavors with Packaging Films. 2, Journal of Agricultural and Food Chemistry, 10.1021/jf00048a046, 42, 12, 2893-2895, 1994.12, A further approach to derive the thermodynamic sorption equation for aqueous phase was performed by estimating the molar heat of sorption (ΔHs) accurately. On the basis of the findings that the sorption of a volatile compound depends on both its molar heat of mixing into film and its enthalpy change toward film, the following equation could be successfully derived: S = S0 exp γ, [Vv[(δwv)2 —, δc2]/RT]. The plots of In S into LDPE film vs the term of the equation gave more adequate improvement in the correlation (r = 0.968). Taking into account the volatility (α) of a volatile compound from solution, further improvement of the equation was made: S = α, S0 exp γ, [Vv[(δwv)2 —, δc2]/RT]. The plots of In S/α, vs the term of the equation for both sugar-ester and SDS solutions gave a sufficient correlation (r = 0.959). Furthermore, the equation could be sufficiently applied to various polymers (PP, r = 0.931, EVA, r = 0.963, EVOH, r = 0.932)..
276. Masaomi Fukamachi, Toshiro Matsui, Mitsuya Shimoda, Yutaka Osajima, Crosslinking Treatment of EVA Film To Improve Flavor Preservation, Journal of Agricultural and Food Chemistry, 10.1021/jf00045a029, 42, 9, 1989-1992, 1994.09, Surface cross-linking treatment of ethylene—vinyl acetate copolymer (EVA) film was performed by formalization in a moderate condition. This treatment led to a marked depression of flavor sorptions. Maximal sorption depression was observed for 18.8 mmol % formalized film, and the maximal depression ratio of solubility coefficient against the unformalized one was about 54% for decane. To elucidate this phenomenon, sorption depression ratios against molecular size were plotted. The sorption of flavors was linearly depressed with an increase in the molecular sizes of the compounds, and the plots for ethyl esters, aldehydes, and alcohols were on the same line (r = 0.842). According to the SEM analysis, which revealed the formation of cross-linkage in the formalized film, the depression effect may be attributed to a restriction of the chain mobility in amorphous regions..
277. Toshiro Matsui, Hiroko Iwasaki, Kiyoshi Matsumoto, Yutaka Osajima, Nmr Studies of Cyclodextrin Inclusion Complex with Ethyl Hexanoate in Ethanol Solution, Bioscience, Biotechnology and Biochemistry, 10.1271/bbb.58.1102, 58, 6, 1102-1106, 1994.01, The formation of a βCD inclusion complexfor aliphatic ethyl ester, with ethyl hexanoateas a guest molecule was investigated. Proton T1 measurements by the IR method and ID difference nuclear Overhauser enhancement experiments showed that ethyl hexanoate exists with the groups (H-2 and H-3) around the ester bond nearer to the narrower βCD cavity and the other protons are proximal to the H(CD)-3 and H(CD)-5 protons within the cavity with a folded structure. The complexation of βCDwas greatly affected by the addition of ethanol. With increasing ethanol concentration, a marked increase in volatility of ethyl hexanoate from the βCD solution was observed; the volatility in 30% ethanol was about 3 times larger than in 0% one. On the basis of the observed NOE and T1 values, the lowering of the abilityof PCD complexation in ethanol solution is assumed to be caused by the situation shift of guest molecule toward the narrower side or outside of the cavity..
278. Toshiro Matsui, Hiroko Iwasaki, Kiyoshi Matsumoto, Yutaka Osajima, Nmr studies of cyclodextrin inclusion complex with ethyl hexanoate in ethanol solution, Bioscience, Biotechnology and Biochemistry, 10.1080/bbb.58.1102, 58, 6, 1102-1106, 1994.01, The formation of a βCD inclusion complex for aliphatic ethyl ester, with ethyl hexanoate as a guest molecule was investigated. Proton T1 measurements by the IR method and 1D difference nuclear Overhauser enhancement experiments showed that ethyl hexanoate exists with the groups (H-2 and H-3) around the ester bond nearer to the narrower βCD cavity and the other protons are proximal to the H(CD)-3 and H(CD)-5 protons within the cavity with a folded structure. The complexation of βCD was greatly affected by the addition of ethanol. With increasing ethanol concentration, a marked increase in volatility of ethyl hexanoate from the βCD solution was observed; the volatility in 30% ethanol was about 3 times larger than in 0% one. On the basis of the observed NOE and T1 values, the lowering of the abilitys of βCD complexation in ethanol solution is assumed to be caused by the situation shift of guest molecule toward the narrower side or outside of the cavity..
279. Hiroshi Matsufuji, Toshiro Matsui, Eiji Seki, Katsuhiro Osajima, Masatoshi Nakashima, Yutaka Osajima, Angiotensin i-converting enzyme inhibitory peptides in an alkaline protease hydrolyzate derived from sardine muscle, Bioscience, Biotechnology and Biochemistry, 10.1080/bbb.58.2244, 58, 12, 2244-2245, 1994, The ACE inhibitory activity of an alkaline protease hydrolyzate from sardine muscle did not change after being treated by gastrointestinal proteases (IC50 = 0.082mg protein/ml). Eleven new ACE inhibitory peptides, constructed with 2 to 4 amino acid residues, were isolated from the hydrolyzate. The ACE inhibitory activity of each was mostly below 100 μM of IC50 value; the maximal inhibitory activity was observed for Lys-Trp (IC50 = 1.63 μM). The isolated peptides inhibited ACE competitively, except for Met-Tyr with non-competitive inhibition. As the result of sequence homology, Arg-Val-Tyr isolated from the hydrolyzate was found in the primary structure of angiotensins I, II, and III, and of des Asp[1]-angiotensin I..
280. Toshiro Matsui, Yutaka Osajima, Evaluation and Design of Food Packaging Films to Improve Flavor Preservation, Nippon Nogeikagaku Kaishi, 10.1271/nogeikagaku1924.68.1321, 68, 9, 1321-1324, 1994.
281. Yutaka Osajima, Toshiro Matsui, Sorption of Flavors into Food Packaging Films, Nippon Nogeikagaku Kaishi, 10.1271/nogeikagaku1924.68.1298, 68, 9, 1298-1301, 1994.
282. Yutaka Osajima, Toshiro Matsui, Dynamic Approach to the Sorption of Flavors into a Food Packaging Film, Analytical Sciences, 10.2116/analsci.9.753, 9, 6, 753-763, 1993, A new analytical method for determining the diffusion, permeation and solubility coefficients of flavors into food packaging materials has been established. The proposed method for gaseous and aqueous samples is based on the monitoring of the flavors that have passed through a film by a flame ionization detector. One can thus predict the dynamic sorption behavior of flavors in food packaging materials under a low vapor pressure. The factors which affect the sorption behavior were elucidated by using of the present method. In order to improve the sorption property of packaging materials, modifications of the packaging materials by electron-beam irradiation and by hydrolysis for ethylene vinyl acetate copolymer (EVA) and polyethylene films were studied. In both modified films, the sorption depression was observed for volatile compounds with a low solubility parameter (SP) value; this effect resulted from a restriction of the chain mobility by mild crosslinking and a lowering of the affinity by surface polarization for irradiated and hydrolyzed films, respectively. Furthermore, by using the proposed thermodynamic affinity concept, represented as the twodimensional distance (δC) between two SP values of film and flavor, packaging materials with high flavor preservation against sorption can be designed..
283. Toshiro Matsui, Hiroshi Matsufuji, Masatoshi Nakashima, Yutaka Osajima, Eiji Seki, Katsuhiro Osajima, Inhibition of Angiotensin I-converting Enzyme by Bacillus licheniformis Alkaline Protease Hydrolyzates Derived from Sardine Muscle, Bioscience, Biotechnology and Biochemistry, 10.1271/bbb.57.922, 57, 6, 922-925, 1993, Hydrolyzates which inhibit the angiotensin I-converting enzyme (ACE) were prepared from sardine muscle by Bacillus licheniformis alkaline protease. Considering the practical application of preparations as a functional food material, the best proteolytic conditions with respect to taste, solubility and ACE inhibitory activity were a 0.3 wt% addition of the enzyme and 17-h proteolysis at 50°C and pH 9.0. The preparations under these conditions had potent activity (IC50=0.26 mg protein/ml). Fractionation of the preparations on an ODS column with ethanol resulted in the production of more potent inhibitors. The most potent activity was obtained when eluting with 10% ethanol (IC50=0.015 mg protein/ml). This fraction was apparently rich in acidic amino acids, poor in hydrophobic ones, and effective for use as a physiologically functional food material by virtue of little bitterness, a fish odor and powerful ACE inhibitory activity..
284. Masaomi Fukamachi, Toshiro Matsui, Mitsuya Shimoda, Masatoshi Nakashima, Yutaka Osajima, Sorption Depression of Flavors into Modified EVA Film by Lowering Film-Flavor Affinity, Journal of Agricultural and Food Chemistry, 10.1021/jf00030a018, 41, 6, 929-932, 1993, Surface hydrolysis of ethylene-vinyl acetate copolymer (EVA) film resulted in a specific sorption depression behavior of volatile compounds. The sorptions of hydrocarbons, ethyl octanoate, and decanal into hydrolyzed EVA film were depressed, whereas the sorptions for alcohols were all promoted. To elucidate the phenomena, the solubility parameter (SP) concept was introduced. From the plots of sorptions against the SP values of volatile compounds, for all hydrocarbons, ethyl esters, and aldehydes with the cohesive energy of <19.3 SP value, the sorptions were depressed, while for hexanal and all alcohols with the SP value of >19.3 quite the opposite results were obtained. It was considered that the depression effect may be attributed to the lowering of compatibility at the surface between hydrolyzed film and volatile compounds. Sensory evaluation also supported flavor preservation for hydrolyzed EVA film in lemon juice..
285. Toshiro Matsui, Kazufumi Nagashima, Masaomi Fukamachi, Mitsuya Shimoda, Yutaka Osajima, Application of the Solubility Parameter in Estimating the Sorption Behavior of Flavor into Packaging Film, Journal of Agricultural and Food Chemistry, 10.1021/jf00022a035, 40, 10, 1902-1905, 1992.10, In order to estimate the sorption behaviors of flavors into film packaging, a two-dimensional approach based on the affinity of flavor for film was performed. When the solubility parameter (SP) value is divided into polar and nonpolar components, the affinity can be represented as a two-dimensional distance (δc) between two SP values of film and flavor. On the basis of this δc concept, the sorptions of flavors into MDPE and EVOH films in the aqueous phase were proved to depend on the δc value; the logarithms of the solubility coefficient decreased linearly with an increase in δc value, i.e., about one-sixth decrease for one δc value. In addition, a large negative slope of the line indicated that the sorption was remarkably influenced by affinity (δc)..
286. Toshiro Matsui, Ayako Ono, Mitsuya Shimoda, Yutaka Osajima, Thermodynamic Elucidation of Depression Mechanism on Sorption of Flavor Compounds into Electron Beam Irradiated LDPE and EVA Films, Journal of Agricultural and Food Chemistry, 10.1021/jf00015a024, 40, 3, 479-483, 1992.03, Electron beam irradiation for low-density polyethylene (LDPE) film up to 20 Mrad resulted in specific sorption depression behaviors of volatile compounds. The sorptions of octane, ethyl hexanoate, and d-limonene into irradiated film were depressed, whereas the opposite behavior was obtained for octanal and octanol. To elucidate these specific phenomena, a thermodynamic attempt of applying the solubility parameter (SP) value was done. As a result, the sorptions of all hydrocarbons and methyl and ethyl esters composed of more than six carbon atoms corresponding to <8.59 SP value were depressed in all, while sorption promotion was observed for all alcohols. A similar result was obtained for irradiated EVA film, for which the sorption depression was observed only for the volatile compound with <8.93 SP value. Calculating the ratio of SP value of volatile compound (δF) to that of irradiated film (δP), the ratios (δFP) for irradiated LDPE and EVA films gave good agreement at 1.09..
287. Toshiro Matsui, Hiroshi Matsufuji, Yutaka Osajima, Colorimetric Measurement of Angiotensin I-Converting Enzyme Inhibitory Activity with Trinitrobenzene Sulfonate, Bioscience, Biotechnology and Biochemistry, 10.1271/bbb.56.517, 56, 3, 517-518, 1992.01.
288. Toshiro Matsui, Mitsuya Shimoda, Yutaka Osajima, Mechanical changes of electron beam irradiated ethylene–vinyl acetate copolymer (EVA) film (I), Polymer International, 10.1002/pi.4990290204, 29, 2, 85-90, 1992, Electron beam irradiation of ethylene‐vinyl acetate copolymer (EVA) film results in a marked depression of sorption of flavour compounds. This effect is presumed to be brought about by radical reactions, following changes in the structure. The crosslinking density and gel fraction increased with irradiation dose, and the maximum percent gel reached 70% for 20 Mrad‐50g kg−1 EVA film, 35% for 20 Mrad‐95g kg−1 EVA film and 50% for 10 Mrad‐150g kg−1 EVA film. In calculating the ratio of scission to crosslinking events, it was found that EVA film is a polymer of the scission type. The degree of crystallinity, Xc decreased significantly with increasing irradiation dose in all irradiated films. For unirradiated films, Xc decreased with increase in vinyl acetate content, which suggests that crystalline regions of EVA film are primarily composed of ethylene units. Therefore, the scission reaction may predominantly take place in the crystalline region, resulting in the formation of methyl or end vinyl groups. This was supported by measuring the film density, peak melting temperature and stress at yield..
289. Hiroyuki Ukeda, Hiroshi Matsufuji, Toshiro Matsui, Yutaka Osajima, Hideki Matsuda, Katsuhiro Osajima, Peptides from Peptic Hydrolyzate of Heated Sardine Meat That Inhibit Angiotensin I Converting Enzyme, Nippon Nogeikagaku Kaishi, 10.1271/nogeikagaku1924.66.25, 66, 1, 25-29, 1992, Three peptides that inhibited angiotensin I converting enzyme (ACE) were isolated from a peptic hydrolyzate of heated sardine muscle. The preparation involved SP-Sephadex C-25 and Toyopearl HW-40 chromatography followed by three steps of high-performance liquid chromatography. The amino acid sequences of these peptides, identified by Edman degradation, were: values of these peptides for ACE from rabbit lung were 83, 30, and 188 μM, respectively. These peptides were synthesized by the solid-phase method, and the IC50 values of the synthetic peptides were similar to those of B-1, B-2, and B-3. These results indicated that all amino acids in B-1, B-2, and B-3 may be in the L-configuration. Fourteen kinds of actins derived from humans, rabbits, rats, mice, soy beans, maize, and so on contained the B-1 sequence of five amino acids..
290. Toshiro Matsui, Mitsuya Shimoda, Yutaka Osajima, Structural analysis of electron beam irradiated ethylene‐vinyl acetate copolymer (EVA) film (II), Polymer International, 10.1002/pi.4990290205, 29, 2, 91-95, 1992, The crosslinked structure of irradiated ethylene‐vinyl acetate copolymer (EVA) film was examined by means of ESR, IR and pyrolysis‐gas chromatography. The ESR spectrum of 35 Mrad irradiated EVA film with 95g kg−1 vinyl acetate content consisted of a three‐line component with an intensity ratio of 1:2:1, a hyperfine structure coupling of 22.4 G and g factor of 2.0049. Therefore, the spectrum was assigned to the methylene radical with two α protons on the same plane; this radical is formed by loss of a hydrogen atom from the acetoxymethyl group. In pyrolysing EVA films at 500°C, the yield of acetic acid from 10 Mrad‐150 g kg−1 film significantly decreased compared with that of unirradiated film, and it decreased with increasing crosslinking density. By measuring the IR spectra of methanolysed EVA films, the following results were obtained: the absorbances at 1740, 1250 and 1050cm−1, attributed to the CO, OCOR and COC groups, respectively, had a marked decrease, whereas the three peaks for 20Mrad film were much stronger than those of unirradiated film. On the basis of these findings, it is suggested that the crosslinking reaction in electron beam irradiated EVA film with lower doses takes place between the acetoxy groups and the main chains..
291. Toshiro Matsui, Masahiro Inoue, Mitsuya Shimoda, Yutaka Osajima, Sorption of volatile compounds into electron beam irradiated EVA film in the vapour phase, Journal of the Science of Food and Agriculture, 10.1002/jsfa.2740540114, 54, 1, 127-135, 1991, In order to investigate the sorption of volatile compounds by electron beam irradiated ethylene/vinyl acetate copolymer (EVA) films, permeation measurements in the vapour phase were carried out. The diffusion coefficients of octane, ethyl hexanoate, octanal, octan‐1‐ol and d‐limonene increased with an increase in the irradiation dose. The sorption of all volatile compounds in this study was depressed in electron beam irradiated film: the decreases in solubility coefficients for 20 Mrad EVA film were 15% for octane and ethyl hexanoate, 45% for octan‐1‐ol and octanal, and 50% for d‐limonene. The enthalpy change in sorption (ΔH) of ethyl hexanoate was −13·4 kJ mol−1 for 50 g kg−1 EVA film at a dose of 20 Mrad compared with −27·6 kJ mol−1 for the unirradiated one. In a homologous series of aliphatic alcohols, sorption was significantly depressed with increasing carbon chain length. Judging from both heat‐seal strength and sorption behaviours, the most appropriate irradiation dose for the practical usage of irradiated EVA film was less than 15, 10 and 5 Mrad for 50, 95 and 150 g kg−1 EVA film, respectively..
292. Toshiro Matsui, Seiya Mizumoto, Akitada Kotani, Hiroki Imakura, Mitsuya Shimoda, Yutaka Osajima, Depression of sorption of volatile compounds into EVA film by electron beam irradiation, Journal of the Science of Food and Agriculture, 10.1002/jsfa.2740500409, 50, 4, 507-515, 1990, Decrease in solubility of volatile compounds (octan‐l‐ol, octanal, ethyl hexanoate, octane and d‐limonene) into a film liner was studied after electron beam irradiation up to 20 Mrad of ethylene vinyl acetate copolymer (EVA) film. The solubility coefficient decreased gradually during ageing despite no change immediately after the irradiation. In all films dosed with 5‐20 Mrad the sorption was depressed about 40% in comparison with the unirradiated one after 4 months. The behaviour was consistent with that of the decay of the radicals in the films. The enthalpy change in sorption (ΔH) was −18.0 kJ mol−1 for 5 Mrad ethylene vinyl acetate copolymer film compared with −48.1 kJ mol−1 for the unirradiated one. In a homologous series, sorption was significantly depressed with increasing carbon chain length of the volatile compound. The specific sorption depression effect was observed for low polarity compounds such as hydrocarbons, aliphatic esters and d‐limonene. The diffusion coefficient of the sorbed compounds increased about 1.6 times after 3 months when irradiated to 20 Mrad..