Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Yasuno Yoko Last modified date:2023.12.06

Assistant Professor / Organic Chemistry and Biochemistry / Department of Chemistry / Faculty of Sciences


Papers
1. Bubwoong Kang, Yuki Shimizu, Yusaku Tamura, Eigo Fukuda, Ken-Ichiro Hamamoto, Yuichiro Uchida, Yoko Yasuno, Atsushi Nakayama, Tetsuya Satoh, Masaki Kuse, Tetsuro Shinada, Formylation Reaction of Amines Using N-Formylcarbazole., Chemical & pharmaceutical bulletin, 10.1248/cpb.c22-00161, 70, 7, 492-497, 2022.07, Formamides are useful starting materials for pharmaceutical syntheses. Although various synthetic methods have been documented in this regard, the use of N-formylcarbazole as a formylation reagent for amines has not yet been reported. We report here the first examples of the use of N-formylcarbazole for the formylation of amines. The characteristic reactivity of N-formylcarbazole enables the selective formylation of sterically less hindered aliphatic primary and secondary amines. In contrast, sterically bulkier amines and weakly nucleophilic amines such as anilines are less reactive under the reaction conditions..
2. Mutsumi Komeyama, Kohsuke Kanno, Hiroyuki Mino, Yoko Yasuno, Tetsuro Shinada, Tomokazu Ito, Hisashi Hemmi, A [4Fe-4S] cluster resides at the active center of phosphomevalonate dehydratase, a key enzyme in the archaeal modified mevalonate pathway., Frontiers in microbiology, 10.3389/fmicb.2023.1150353, 14, 1150353-1150353, 2023.03, The recent discovery of the archaeal modified mevalonate pathway revealed that the fundamental units for isoprenoid biosynthesis (isopentenyl diphosphate and dimethylallyl diphosphate) are biosynthesized via a specific intermediate, trans-anhydromevalonate phosphate. In this biosynthetic pathway, which is unique to archaea, the formation of trans-anhydromevalonate phosphate from (R)-mevalonate 5-phosphate is catalyzed by a key enzyme, phosphomevalonate dehydratase. This archaea-specific enzyme belongs to the aconitase X family within the aconitase superfamily, along with bacterial homologs involved in hydroxyproline metabolism. Although an iron-sulfur cluster is thought to exist in phosphomevalonate dehydratase and is believed to be responsible for the catalytic mechanism of the enzyme, the structure and role of this cluster have not been well characterized. Here, we reconstructed the iron-sulfur cluster of phosphomevalonate dehydratase from the hyperthermophilic archaeon Aeropyrum pernix to perform biochemical characterization and kinetic analysis of the enzyme. Electron paramagnetic resonance, iron quantification, and mutagenic studies of the enzyme demonstrated that three conserved cysteine residues coordinate a [4Fe-4S] cluster-as is typical in aconitase superfamily hydratases/dehydratases, in contrast to bacterial aconitase X-family enzymes, which have been reported to harbor a [2Fe-2S] cluster..
3. Tetsuro Shinada, Atsushi Nakayama, Hironori Okamura, Yoko Yasuno, Recent Progress in the Synthesis of Deuterated Aldehyde, Bulletin of the Chemical Society of Japan, 10.1246/bcsj.20220202, 95, 10, 1461-1473, 2022.10.
4. Bubwoong Kang, Yuki Shimizu, Yusaku Tamura, Eigo Fukuda, Ken-Ichiro Hamamoto, Yuichiro Uchida, Yoko Yasuno, Atsushi Nakayama, Tetsuya Satoh, Masaki Kuse, Tetsuro Shinada, Formylation Reaction of Amines Using N-Formylcarbazole, Chemical & Pharmaceutical Bulletin, https://doi.org/10.1248/cpb.c22-00161, 70, 7, 492-497, 2022.07.
5. Shogo Iwakata, Kazuya Asada, Tomoyuki Nishi, Rafaella Stepanova, So Shinoda, Daijiro Ueda, Masahiro Fujihashi, Yoko Yasuno, Tetsuro Shinada, Tsutomu Sato, Insight into the mechanism of geranyl-β-phellandrene formation catalyzed by Class IB terpene synthases., Bioscience, biotechnology, and biochemistry, 10.1093/bbb/zbac036, 86, 6, 724-729, 2022.03, Terpene synthase (TS) from Bacillus alcalophilus (BalTS) is the only Class IB TS for which a 3D structure has been elucidated. Recently, geranyl-β-phellandrene, a novel cyclic diterpene, was identified as a product of BalTS in addition to the acyclic β-springene. In the present study, we have provided insight into the mechanism of geranyl-β-phellandrene formation. Deuterium labeling experiments revealed that the compound is produced via a 1,3-hydride shift. In addition, non-enzymatic reactions using divalent metal ions were performed. The enzyme is essential for the geranyl-β-phellandrene formation. Furthermore, BalTS variants targeting tyrosine residues enhanced the yield of geranyl-β-phellandrene and the proportion of the compound of the total products. It was suggested that the expansion of the active site space may allow the conformation of the intermediates necessary for cyclization. The present study describes the first Class IB TSs to successfully alter product profiles while retaining high enzyme activity..
6. Atsushi Nakayama, Yoko Yasuno, Yuki Yamamoto, Kai Saito, Kohei Kitsuwa, Hironori Okamura, Tetsuro Shinada, Stereoselective Syntheses of trans-Anhydromevalonic Acid and trans-Anhydromevalonyl Group-Containing Natural Products., Journal of natural products, 10.1021/acs.jnatprod.1c01176, 85, 4, 1052-1058, 2022.02, Collective total syntheses of trans-anhydromevalonic acid (tAHMA) and trans-anhydromevalonyl (tAHM) group-containing natural products (pestalotiopin A, pestalotiopamide C, pestalotiopamide D, farinomalein E, eleutherazine B, and trichocyclodipeptide A) were achieved using tAHMA esters as key intermediates. To this end, tAHMA tert-butyl ester was newly prepared by Z-vinyltosylation of tert-butyl 3-oxo-5-((triisopropylsilyl)oxy)pentanoate followed by the Negishi cross-coupling reaction with Me2Zn. tAHMA esters were converted to the target natural products via esterification or amidation. Comparison of the spectroscopic data of synthetic and natural products confirmed the E-configuration of the tAHM moieties in the natural products..
7. Yoko Yasuno, Atsushi Nakayama, Kai Saito, Kohei Kitsuwa, Hironori Okamura, Mutsumi Komeyama, Hisashi Hemmi, Tetsuro Shinada, Total Synthesis and Structure Confirmation of trans-Anhydromevalonate-5-phosphate, a Key Biosynthetic Intermediate of the Archaeal Mevalonate Pathway, Journal of Natural Products, 10.1021/acs.jnatprod.1c00615, 84, 10, 2749-2754, 2021.10, The mevalonate pathway is an upstream terpenoid biosynthetic route of terpenoids for providing the two five-carbon units, dimethylallyl diphosphate, and isopentenyl diphosphate. Recently, trans-anhydromevalonate-5-phosphate (tAHMP) was isolated as a new biosynthetic intermediate of the archaeal mevalonate pathway. In this study, we would like to report the first synthesis of tAHMP and its enzymatic transformation using one of the key enzymes, mevalonate-5-phosphate dehydratase from a hyperthermophilic archaeon, Aeropyrum pernix. Starting from methyl tetrolate, a Cu-catalyzed allylation provided an E-trisubstituted olefin in a stereoselective manner. The resulting E-olefin was transformed to tAHMP by cleavage of the olefin and phosphorylation. The structure of the synthetic tAHMP was unambiguously determined by NOESY analysis..
8. Hironori Okamura, Yoko Yasuno, Atsushi Nakayama, Katsushi Kumadaki, Kohei Kitsuwa, Keita Ozawa, Yusaku Tamura, Yuki Yamamoto, Tetsuro Shinada, Selective oxidation of alcohol-d1 to aldehyde-d1 using MnO2, RSC Advances, 10.1039/d1ra05405h, 11, 46, 28530-28534, 2021.08, A facile method for deutrium incorporation into aldehydes by mild reduction of NaBD4 of aldehydes and MnO2 oxidation (98% D) is disclosed..
9. Shouya Naruse, Mayuko Ogino, Takao Nakagawa, Yoko Yasuno, Akiya Jouraku, Takahiro Shiotsuki, Tetsuro Shinada, Ken Miura, Chieka Minakuchi, Ovicidal activity of juvenile hormone mimics in the bean bug, Riptortus pedestris., Journal of pesticide science, 10.1584/jpestics.D20-075, 46, 1, 60-67, 2021.02, Insect juvenile hormone (JH) mimics (JHMs) are known to have ovicidal effects if applied to adult females or eggs. Here, we examined the effects of exogenous JHMs on embryonic development of the bean bug, Riptortus pedestris. The expression profiles of JH early response genes and JH biosynthetic enzymes indicated that JH titer was low for the first 3 days of the egg stage and increased thereafter. Application of JH III skipped bisepoxide (JHSB3) or JHM on Day 0 eggs when JH titer was low caused reduced hatchability, and the embryos mainly arrested in mid- or late embryonic stage. Application of JHMs on Day 5 eggs also resulted in an arrest, but this was less effective compared with Day 0 treatment. Interestingly, ovicidal activity of synthetic JHMs was much lower than that of JHSB3. This study will contribute to developing novel insecticides that are selective among insect species..
10. Shinichi Ishiguro, Tetsuro Shinada, Zhou Wu, Mayumi Karimazawa, Michimasa Uchidate, Eiji Nishimura, Yoko Yasuno, Makiko Ebata, Piyamas Sillapakong, Hiromi Ishiguro, Nobuyoshi Ebata, Junjun Ni, Muzhou Jiang, Masanobu Goryo, Keishi Otsu, Hidemitsu Harada, Koichi Suzuki, A novel cyclic peptide (Naturido) modulates glia-neuron interactions in vitro and reverses ageing-related deficits in senescence-accelerated mice., PloS one, 10.1371/journal.pone.0245235, 16, 1, e0245235, 2021.01, The use of agents that target both glia and neurons may represent a new strategy for the treatment of ageing disorders. Here, we confirmed the presence of the novel cyclic peptide Naturido that originates from a medicinal fungus (Isaria japonica) grown on domestic silkworm (Bombyx mori). We found that Naturido significantly enhanced astrocyte proliferation and activated the single copy gene encoding the neuropeptide VGF and the neuron-derived NGF gene. The addition of the peptide to the culture medium of primary hippocampal neurons increased dendrite length, dendrite number and axon length. Furthermore, the addition of the peptide to primary microglial cultures shifted CGA-activated microglia towards anti-inflammatory and neuroprotective phenotypes. These findings of in vitro glia-neuron interactions led us to evaluate the effects of oral administration of the peptide on brain function and hair ageing in senescence-accelerated mice (SAMP8). In vivo analyses revealed that spatial learning ability and hair quality were improved in Naturido-treated mice compared with untreated mice, to the same level observed in the normal ageing control (SAMR1). These data suggest that Naturido may be a promising glia-neuron modulator for the treatment of not only senescence, but also Alzheimer's disease and other neurodegenerative diseases..
11. Kei Miyako, Yoko Yasuno, Tetsuro Shinada, Masaki J Fujita, Ryuichi Sakai, Diverse Aromatic Metabolites in the Solitary Tunicate Cnemidocarpa irene., Journal of natural products, 10.1021/acs.jnatprod.0c00789, 83, 10, 3156-3165, 2020.10, Fourteen aromatic metabolites (6-19) were isolated from an aqueous extract of the solitary tunicate Cnemidocarpa irene collected in Hokkaido, Japan. The structures of the metabolites were determined based on the spectroscopic interpretations, including one- and two-dimensional NMR, mass spectra, UV, and circular dichroism data. The biopterin analogue 10 modulated the behavior of mice after intracerebroventricular injection and showed a weak affinity to ionotropic glutamate receptor subtypes. Analyses of fluorescent coelomic fluid of the tunicate revealed that pterin 12 was responsible for the fluorescence of the blood cells, while β-carbolines 1 and 3 were fluorescent compounds in the serum. The metabolic profiles in adults, juveniles, larvae, and eggs of the animal differed substantially, suggesting that the metabolism of the animal, especially biosynthesis of aromatic secondary metabolites, changes over different life stages..
12. Rafaella Stepanova, Hayato Inagi, Kei Sugawara, Kazuya Asada, Tomoyuki Nishi, Daijiro Ueda, Yoko Yasuno, Tetsuro Shinada, Kunio Miki, Masahiro Fujihashi, Tsutomu Sato, Characterization of Class IB Terpene Synthase: The First Crystal Structure Bound with a Substrate Surrogate., ACS chemical biology, 10.1021/acschembio.0c00145, 15, 6, 1517-1525, 2020.06, Terpene synthases (TS) are classified into two broad types, Class I and II, based on the chemical strategy for initial carbocation formation and motif sequences of the catalytic site. We have recently identified a new class of enzymes, Class IB, showing the acceptability of long (C20-C35) prenyl-diphosphates as substrates and no amino acid sequence homology with known TS. Conversion of long prenyl-diphosphates such as heptaprenyl-diphosphate (C35) is unusual and has never been reported for Class I and II enzymes. Therefore, the characterization of Class IB enzymes is crucial to understand the reaction mechanism of the extensive terpene synthesis. Here, we report the crystal structure bound with a substrate surrogate and biochemical analysis of a Class IB TS, using the enzyme from Bacillus alcalophilus (BalTS). The structure analysis revealed that the diphosphate part of the substrate is located around the two characteristic Asp-rich motifs, and the hydrophobic tail is accommodated in a unique hydrophobic long tunnel, where the C35 prenyl-diphosphate, the longest substrate of BalTS, can be accepted. Biochemical analyses of BalTS showed that the enzymatic property, such as Mg2+ dependency, is similar to those of Class I enzymes. In addition, a new cyclic terpene was identified from BalTS reaction products. Mutational analysis revealed that five of the six Asp residues in the Asp-rich motifs and two His residues are essential for the formation of the cyclic skeleton. These results provided a clue to consider the application of the unusual large terpene synthesis by Class IB enzymes..
13. Yoko Yasuno, Iho Mizutani, Yuki Sueuchi, Yuuka Wakabayashi, Nozomi Yasuo, Keiko Shimamoto, Tetsuro Shinada, Catalytic Asymmetric Hydrogenation of Dehydroamino Acid Esters with Biscarbamate Protection and Its Application to the Synthesis of xCT Inhibitors., Chemistry (Weinheim an der Bergstrasse, Germany), 10.1002/chem.201900289, 25, 20, 5145-5148, 2019.04, Catalytic asymmetric hydrogenation of dehydroamino acid esters with biscarbamate protection was examined for the first time to prepare optically active amino acids. The new method was successfully applied to the synthesis of new cystine-glutamate exchanger inhibitors..
14. Yusuke Totsuka, Yoko Yasuno, Tetsuro Shinada, First synthesis of all-trans-polyprenol with 100 carbons, Chemistry Letters, 10.1246/cl.190046, 48, 5, 491-494, 2019.01, © 2019 The Chemical Society of Japan. All-trans polyprenols consisting of one hundred carbons (C100) have been synthesized for the first time via the sulfone coupling of C45 and C55 fragments. The resulting coupling product with four benzenesulfonyl groups were subjected to desulfonylation reaction using Pd(dppp)Cl2/LiBHEt3 followed by removal of the benzyl group at the tail under Benkeser reduction conditions to furnish the title compound..
15. Haruna Saeki, Ryota Hara, Hironobu Takahashi, Miu Iijima, Ryosuke Munakata, Hiromichi Kenmoku, Kazuma Fuku, Ai Sekihara, Yoko Yasuno, Tetsuro Shinada, Daijiro Ueda, Tomoyuki Nishi, Tsutomu Sato, Yoshinori Asakawa, Fumiya Kurosaki, Kazufumi Yazaki, Futoshi Taura, An Aromatic Farnesyltransferase Functions in Biosynthesis of the Anti-HIV Meroterpenoid Daurichromenic Acid., Plant physiology, 10.1104/pp.18.00655, 178, 2, 535-551, 2018.10, Rhododendron dauricum produces daurichromenic acid, an anti-HIV meroterpenoid, via oxidative cyclization of the farnesyl group of grifolic acid. The prenyltransferase (PT) that synthesizes grifolic acid is a farnesyltransferase in plant specialized metabolism. In this study, we demonstrated that the isoprenoid moiety of grifolic acid is derived from the 2-C-methyl-d-erythritol-4-phosphate pathway that takes place in plastids. We explored candidate sequences of plastid-localized PT homologs and identified a cDNA for this PT, RdPT1, which shares moderate sequence similarity with known aromatic PTs. RdPT1 is expressed exclusively in the glandular scales, where daurichromenic acid accumulates. In addition, the gene product was targeted to plastids in plant cells. The recombinant RdPT1 regiospecifically synthesized grifolic acid from orsellinic acid and farnesyl diphosphate, demonstrating that RdPT1 is the farnesyltransferase involved in daurichromenic acid biosynthesis. This enzyme strictly preferred orsellinic acid as a prenyl acceptor, whereas it had a relaxed specificity for prenyl donor structures, also accepting geranyl and geranylgeranyl diphosphates with modest efficiency to synthesize prenyl chain analogs of grifolic acid. Such a broad specificity is a unique catalytic feature of RdPT1 that is not shared among secondary metabolic aromatic PTs in plants. We discuss the unusual substrate preference of RdPT1 using a molecular modeling approach. The biochemical properties as well as the localization of RdPT1 suggest that this enzyme produces meroterpenoids in glandular scales cooperatively with previously identified daurichromenic acid synthase, probably for chemical defense on the surface of R. dauricum plants..
16. Eiji Nishimura, Yoko Yasuno, Tetsuro Shinada, Improved total synthesis of (±)-Tetragocarbone A, Tetrahedron, 10.1016/j.tet.2018.04.024, 74, 21, 2664-2668, 2018.05, Stereoselective total synthesis of (±)-tetragocarbone A isolated from the propolis of an Australian stingless bee, Tetragonula carbonaria, has been developed by focusing on the latent symmetry of 1. The requisite 1R*, 3R*, 6S* stereogenic centers were selectively installed by hydroxy group directing reactions including the late stage desymmetrization of the 1,3-diketone. The target natural product was successfully prepared in 12 steps from phloroglucinol on 300 mg..
17. Masahiro Fujihashi, Tsutomu Sato, Yuma Tanaka, Daisuke Yamamoto, Tomoyuki Nishi, Daijiro Ueda, Mizuki Murakami, Yoko Yasuno, Ai Sekihara, Kazuma Fuku, Tetsuro Shinada, Kunio Miki, Crystal structure and functional analysis of large-terpene synthases belonging to a newly found subclass., Chemical science, 10.1039/c8sc00289d, 9, 15, 3754-3758, 2018.04, Thousands of terpenes have been identified to date. However, only two classes of enzymes are known to be involved in their biosynthesis, and each class has characteristic amino-acid motifs. We recently identified a novel large-terpene (C25/C30/C35) synthase, which shares no motifs with known enzymes. To elucidate the molecular mechanism of this enzyme, we determined the crystal structure of a large-β-prene synthase from B. alcalophilus (BalTS). Surprisingly, the overall structure of BalTS is similar to that of the α-domain of class I terpene synthases although their primary structures are totally different from each other. Two novel aspartate-rich motifs, DYLDNLxD and DY(F,L,W)IDxxED, are identified, and mutations of any one of the aspartates eliminate its enzymatic activity. The present work leads us to propose a new subclass of terpene synthases, class IB, which is probably responsible for large-terpene biosynthesis..
18. Takeo Tomita, Masaya Kobayashi, Yuma Karita, Yoko Yasuno, Tetsuro Shinada, Makoto Nishiyama, Tomohisa Kuzuyama, Structure and Mechanism of the Monoterpene Cyclolavandulyl Diphosphate Synthase that Catalyzes Consecutive Condensation and Cyclization, Angewandte Chemie - International Edition, 10.1002/anie.201708474, 56, 47, 14913-14917, 2017.11, We report the three-dimensional structure of cyclolavandulyl diphosphate (CLPP) synthase (CLDS), which consecutively catalyzes the condensation of two molecules of dimethylallyl diphosphate (DMAPP) followed by cyclization to form a cyclic monoterpene, CLPP. The structures of apo-CLDS and CLDS in complex with Tris, pyrophosphate, and Mg2+ ion were refined at 2.00 Å resolution and 1.73 Å resolution, respectively. CLDS adopts a typical fold for cis-prenyl synthases and forms a homo-dimeric structure. An in vitro reaction using a regiospecifically 2H-substituted DMAPP substrate revealed the intramolecular proton transfer mechanism of the CLDS reaction. The CLDS structure and structure-based mutagenesis provide mechanistic insights into this unprecedented terpene synthase. The combination of structural and mechanistic insights advances the knowledge of intricate terpene synthase-catalyzed reactions..
19. Takeo Tomita, Masaya Kobayashi, Yuma Karita, Yoko Yasuno, Tetsuro Shinada, Makoto Nishiyama, Tomohisa Kuzuyama, Structure and Mechanism of the Monoterpene Cyclolavandulyl Diphosphate Synthase that Catalyzes Consecutive Condensation and Cyclization., Angewandte Chemie (International ed. in English), 10.1002/anie.201708474, 56, 47, 14913-14917, 2017.11, We report the three-dimensional structure of cyclolavandulyl diphosphate (CLPP) synthase (CLDS), which consecutively catalyzes the condensation of two molecules of dimethylallyl diphosphate (DMAPP) followed by cyclization to form a cyclic monoterpene, CLPP. The structures of apo-CLDS and CLDS in complex with Tris, pyrophosphate, and Mg2+ ion were refined at 2.00 Å resolution and 1.73 Å resolution, respectively. CLDS adopts a typical fold for cis-prenyl synthases and forms a homo-dimeric structure. An in vitro reaction using a regiospecifically 2 H-substituted DMAPP substrate revealed the intramolecular proton transfer mechanism of the CLDS reaction. The CLDS structure and structure-based mutagenesis provide mechanistic insights into this unprecedented terpene synthase. The combination of structural and mechanistic insights advances the knowledge of intricate terpene synthase-catalyzed reactions..
20. Yasuhiro Sugime, Dai Watanabe, Yoko Yasuno, Tetsuro Shinada, Toru Miura, Nobuaki K Tanaka, Upregulation of Juvenile Hormone Titers in Female Drosophila melanogaster Through Mating Experiences and Host Food Occupied by Eggs and Larvae., Zoological science, 10.2108/zs160150, 34, 1, 52-57, 2017.02, Juvenile hormone (JH) plays a crucial role in the determination of developmental timing in insects. In Drosophila melanogaster, reports indicate that JH titers are the highest immediately following eclosion and that the mating experience increases the titers in females. However, the titers have not been successively measured for an extended period of time after eclosion. This study reveals that JH titers are increased after eclosion in virgin females when supplied with food that is occupied by eggs and larvae as well as in mated females. With the presence of eggs and larvae, food induced the virgin females to lay unfertilized eggs. When combined with previous work indicating that females are attracted to such food where they prefer to lay eggs, these results suggest that flies can prepare themselves to lay eggs by changing the titers of JH under the presence of growing larvae, ensuring that the food is an appropriate place to oviposit..
21. Yoko Yasuno, Makoto Hamada, Yuya Yoshida, Keiko Shimamoto, Yasushi Shigeri, Toshifumi Akizawa, Motomi Konishi, Yasufumi Ohfune, Tetsuro Shinada, Structure-activity relationship study at C9 position of kaitocephalin., Bioorganic & medicinal chemistry letters, 10.1016/j.bmcl.2016.06.026, 26, 15, 3543-6, 2016.08, Kaitocephalin (KCP) isolated from Eupenicillium shearii PF1191 is an unusual amino acid natural product in which serine, proline, and alanine moieties are liked with carbon-carbon bonds. KCP exhibits potent and selective binding affinity for one of the ionotropic glutamate receptor subtypes, NMDA receptors (Ki=7.8nM). In this study, new structure-activity relationship studies at C9 of KCP were implemented. Eleven new KCP analogs with different substituents at C9 were prepared and employed for binding affinity tests using native ionotropic glutamate receptors. Replacement of the 3,5-dichloro-4-hydroxybenzoyl group of KCP with a 3-phenylpropionyl group resulted in significant loss of binding affinity for NMDARs (Ki=1300nM), indicating an indispensable role of the aromatic ring of KCP in the potent and selective binding to NMDARs. Other analogs showed potent binding affinity in a range of 11-270nM. These findings would directly link to develop useful chemical tools toward imaging and labeling of NMDARs..
22. Yasuno Y, Nishimura A, Yasukawa Y, Karita Y, Ohfune Y, Shinada T, The stereoselective construction of E- and Z-Δ-Ile from E-dehydroamino acid ester: the synthesis of the phomopsin A tripeptide side chain., Chemical communications (Cambridge, England), 10.1039/c5cc08458j, 52, 7, 1478-81, 2016.01.
23. Yoko Yasuno, Makoto Hamada, Masanori Kawasaki, Keiko Shimamoto, Yasushi Shigeri, Toshifumi Akizawa, Motomi Konishi, Yasufumi Ohfune, Tetsuro Shinada, (7S)-Kaitocephalin as a potent NMDA receptor selective ligand., Organic & biomolecular chemistry, 10.1039/c5ob02301g, 14, 4, 1206-10, 2016.01, A structure-activity relationship (SAR) study of kaitocephalin (KCP), known to be a potent naturally occurring NMDA receptor ligand, was performed. This study led us to the discovery of (7S)-kaitocephalin as a highly selective NMDA receptor ligand. It displayed a 22-fold higher degree of selectivity for the NMDA receptor over KCP, though the binding affinity of (7S)-KCP [Ki = 29 nM] was 3.7-fold less potent than that of KCP [Ki = 7.8 nM]..
24. Yoko Yasuno, Yuya Yoshida, Akito Nishimura, Yasufumi Ohfune, Tetsuro Shinada, A FACILE SYNTHESIS OF (2R/S,5R)-1-tert-BUTYL 2-METHYL 5-(((tert-BUTYLDIMETHYLSILYL)OXY)METHYL)PYRROLIDINE-1,2-DICARBOXYLATE, HETEROCYCLES, 10.3987/COM-15-13347, 91, 12, 2377-2385, 2015.12, A facile synthesis of (2R/S,5R)-1-tert-butyl 2-methyl 5-atert-butyldimethylsilypoxy)methyppyrrolidine-1,2-dicarboxylate (12) was efficiently accomplished in 5 steps from aminal 17 via the mild hydrolysis of nitrile 23..
25. Yoko Yasuno, Makoto Hamada, Takeshi Yamada, Tetsuro Shinada, Yasufumi Ohfune, Stereoselective Synthesis of (E)-alpha,beta-Dehydroamino Acid Esters, EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, 10.1002/ejoc.201300112, 2013, 10, 1884-1888, 2013.04, Dehydroamino acid (Dhaa) is recognized as a useful tool or substrate for amino acid and peptide research. Although the stereoselective synthesis of the thermodynamically more stable Z-Dhaa has been well examined and established, the stereoselective synthesis of E-Dhaa has still remained to be a challenging synthetic task. In this paper, a stereoselective synthesis of E-Dhaa esters using a new (alpha-diphenylphosphono) glycine is described. The characteristic aspects of the new method are summarized as follows: (i) metal additives play an important role in the promotion of E-stereoselectivi-ties. (ii) the use of NaI was effected for the synthesis of E-Dhaas bearing an aryl substituent and an amino functionality, (iii) MgBr2 center dot OEt2 and ZnCl2 contributed to improve the E-stereoselective synthesis of E-Dhaas bearing an alkyl substituent and an oxygen functionality, (iv) various protecting and functional groups were compatible under the reaction conditions, and (v) N-Cbz, Boc, and acyl-alpha-(diphenylphosphono) glycines were served for the stereoselective olefination reaction to provide the corresponding E-Dhaas..