Language：English   Publishing type：Research paper (scientific journal)   Publisher：Analytical Chemistry  

For the discovery of sensitive biomarkers of kidney function focusing on chiral amino acids, a multiple heart-cutting two-dimensional (2D) liquid chromatography-mass spectrometry (LC-MS)/MS system has been designed/developed. As the target analytes, alanine (Ala), aspartic acid, glutamic acid (Glu), leucine (Leu), lysine, methionine, phenylalanine (Phe), proline (Pro), serine (Ser), and valine were selected considering the presence of their d-forms in mammals. The 2D LC-MS/MS system consisted of the nonenantioselective reversed-phase separation of the target amino acids, the separations of the d- and l-enantiomers, and detection using MS/MS. Using the method, the plasma chiral amino acids, precolumn derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole, were isolated from other intrinsic substances, then determined without losing sensitivity by the fully automated whole-peak volume transfer operation from first to second dimension. In all of the tested plasma samples obtained from five healthy individuals and 15 patients with chronic kidney disease (CKD), the target chiral amino acids were determined without interference. In healthy individuals, the levels of all the tested d-amino acids were regulated in the low ranges. In contrast, the % d values of Glu, Leu, and Phe significantly increased with the progress of kidney dysfunction, besides the previously reported values of d-Ala, Pro, and Ser. Concerning Phe, the significant increase of the % d values (p < 0.05) was reported for the first time even in the mild CKD group compared to those of the healthy group; d-Phe might be a more sensitive marker than the previously reported d-forms. These results demonstrated the potential of these d-forms as the sensitive biomarkers of kidney function for the early diagnosis of CKD.

DOI： 10.1021/acs.analchem.3c05309

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Journal of Chromatography A  

A highly-selective three-dimensional high-performance liquid chromatographic (3D-HPLC) system was developed for the determination of serine (Ser), threonine (Thr) and allo-threonine (aThr) enantiomers in human plasma to screen the new biomarker of chronic kidney disease (CKD). d-Ser has been reported to be the candidate biomarker of CKD, however, multiple biomarkers are still required. Therefore, Ser analogs of hydroxy amino acids are the focus in the present study. For the sensitive analysis, the amino acids were derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole and detected by their fluorescence. The 3D-HPLC system consisted of a reversed-phase column (Singularity RP18, 1.0 × 250 mm), an anion-exchange column (Singularity AX, 1.0 × 150 mm) and a Pirkle-type chiral stationary phase (Singularity CSP-013S, 1.5 × 250 mm). The developed method was validated and applied to the human plasma samples obtained from 15 healthy volunteers and 165 CKD patients. The concentrations of the d-forms were 1.13-2.26 (Ser), 0.01-0.03 (Thr) and 0.04-0.10 μM (aThr) for the healthy volunteers and 0.95-19.0 (Ser), 0-0.57 (Thr) and 0.04-1.02 μM (aThr) for the CKD patients. The concentrations and the %d values of all the target d-amino acids were increased along with the decreasing of renal function and further investigation for clinical applications are expected.

DOI： 10.1016/j.chroma.2024.464739

Web of Science

Scopus

PubMed

researchmap

Repository Public URL： https://hdl.handle.net/2324/7178699

Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Society for Chromatographic Sciences  

<p>For the highly-selective analysis of lactic acid (LA), 2-hydroxybutyric acid (2HB), 3-hydroxybutyric acid (3HB) and malic acid (MA) enantiomers in human physiological fluids, a three-dimensional (3D) HPLC method following the fluorescence derivatization with 4-nitro-7-piperazino-2,1,3-benzoxadiazole has been designed and developed. The 3D-HPLC system was composed of reversed-phase, mixed-mode and enantioselective columns, and the conditions of all the dimensions were thoroughly investigated. In the first and second dimensions, the target hydroxy acids were separated from most of the interfering substances in the clinical samples. In the third dimension, the enantiomers were separated with resolution values higher than 3.47. The present method was validated by checking the calibration curves, precision and accuracy using standard solutions and human samples, and satisfactory results were acquired. Using the 3D-HPLC system, D-LA, L-LA, D-3HB, L-3HB and L-2HB were determined in the human plasma and urine (MA enantiomers were not determined). The concentrations of the detected enantiomers in the human plasma were 6.2, 660, 34.0, 1.0 and 19.0 µM, and those in the human urine were 13.4, 88.3, 4.5, 3.7 and 4.5 µM, respectively. </p>

DOI： 10.15583/jpchrom.2023.015

Web of Science

CiNii Research

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.jpbao.2023.100013

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Society for Chromatographic Sciences  

<p>Three-dimensional (3D) HPLC methods are useful tools for the selective analysis of biomolecules in complicated real-world matrices, however, the columns applicable for the second dimension are still limited. In the present study, two types of mixed-mode columns (Singularity MX-102 and 103) were newly designed/developed focusing on the separation of <i>N</i>-protected chiral amino acids. The retention profiles of the two mixed-mode columns were evaluated using 10 proteinogenic amino acids with various chemical properties, namely, alanine, asparagine (Asn), glutamine, glycine, lysine (Lys), phenylalanine, proline, serine (Ser), threonine and valine (Val), and compared to that of a mixed-mode column (Singularity MX-001) previously adopted for the 3D-HPLC analysis of chiral amino acids. The amino acids were derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) and detected by their fluorescence (ex. 470 nm, em. 530 nm). For the mobile phases, mixed solutions of acetonitrile/methanol containing formic acid were used. As a result, NBD-Val eluted the fastest for all the tested mixed-mode columns. However, the NBD-amino acids most strongly retained on the columns were different (Asn for MX-001, Ser for MX-102 and Lys for MX-103). Also, the elution orders of the 10 NBD-amino acids on the three mixed-mode columns were not the same as that on the reversed-phase C18 column, and characteristic elution orders and retention properties were observed for the individual mixed-mode columns. These results indicated that mixed-mode columns reported in the present study have different retention mechanisms, and the development of highly selective 3D-HPLC systems using these columns is expected. </p>

DOI： 10.15583/jpchrom.2023.006

Web of Science

CiNii Research

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.jpbao.2023.100004

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Society for Chromatographic Sciences  

<p>A B6DAO^-/- mouse strain lacking D-amino acid oxidase (DAO) activity with the genetic background of C57BL strain, frequently used to produce disease model mice in the current medical/life science areas, was newly developed. In the plasma of the control C57BL/6J and mutant B6DAO^-/- mice, five D-amino acids widely found in mammals were determined using a highly-selective two-dimensional LC-MS/MS system. As the targets, D-alanine (Ala), D-aspartic acid (Asp), D-leucine (Leu), D-proline (Pro) and D-serine (Ser) were selected. All five chiral amino acids were clearly observed, and the D-enantiomers of the neutral amino acids (Ala, Leu, Pro and Ser) significantly increased in the mutant B6DAO^-/- mice (3.69-36.91 nmol/mL) compared to those in the control C57BL/6J mice (0.24-2.03 nmol/mL), whereas the amounts of D-Asp were almost equal between the two strains. The obtained values are consistent with those in previous reports using ddY/DAO^-/- mice having spontaneous DAO deficiency and the control ddY/DAO^+/+ mice. These results indicated that the newly-developed B6DAO^-/- strain is practically useful to clarify the controlling mechanism of intrinsic D-amino acids that are expected as new bio-functional molecules and/or biomarkers in mammals. </p>

DOI： 10.15583/jpchrom.2023.002

Web of Science

CiNii Research

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Society for Chromatographic Sciences  

<p>For the simultaneous determination of lactate (LA), 2-hydroxybutyrate (2HB), 3-hydroxybutyrate (3HB) and malate (MA) enantiomers, a new separation technique in a two-dimensional high-performance liquid chromatography (2D-HPLC) system following the fluorescence derivatization with 4-nitro-7-piperazino-2,1,3-benzoxadiazole has been developed. The 2D-HPLC system was composed of the reversed-phase (1D) and enantioselective (2D) separations. In the first dimension, the target hydroxy acids were separated as their D plus L mixtures on a Singularity RP18 column (1.0 mm i.d. x 250 mm), and the enantiomers were separated in the second dimension using a polysaccharide-based chiral stationary phase, Chiralpak IG (2.0 mm i.d. x 250 mm). By using the Chiralpak IG column, the LA, 2HB, 3HB and MA enantiomers were separated with resolution values of 3.47, 3.63, 6.81 and 3.72, respectively. The developed 2D-HPLC system was applied to human plasma, and trace levels of D-LA and L-3HB in addition to their major antipodes were determined. The acquired %D of LA (the percentage of D-LA over total LA) and %L of 3HB (the percentage of L-3HB over total 3HB) were 1.0 and 2.7, respectively. For 2HB, only the L-form was detected, while the MA enantiomers were not found in the human plasma.</p>

DOI： 10.15583/jpchrom.2022.011

Web of Science

CiNii Research

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

D-Tryptophan (D-Trp) is one of the minor D-enantiomers of amino acids discovered in microbes and mollusca. In the present study, a highly-selective 2D chiral LC-MS/MS method has been designed and developed focusing on the determination of Trp enantiomers to investigate the presence and regulation of free D-Trp in mammals. The developed system consisted of a reversed-phase separation for the first dimension, an enantioselective separation for the second dimension and also the detection using a triple quadrupole mass spectrometer for the third/fourth dimensions. Using the present method, urinary D-Trp in mammals, including healthy human volunteers and mice, were successfully determined. Although only l-Trp was observed in a mixed urine sample of healthy volunteers, small amounts of D-Trp were detected in the C57BL/6J mice (n = 5, %D=6.18 ± 0.47). In B6DAO- mice lacking the activity of d-amino acid oxidase (DAO), relatively high levels of D-Trp were observed (n = 6, %d=27.43 ± 3.26). The obtained %d values of Trp in the urine of the C57BL/6J mice and B6DAO- mice were confirmed using various enantioselective columns having different separation properties. These results indicate that the urinary D-Trp level is regulated by DAO in mammals, and further investigations, such as tissue distribution and physiological significance of the intrinsic D-Trp, are expected.

DOI： 10.1016/j.jpba.2022.114919

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER  

A highly-selective two-dimensional high-performance liquid chromatographic (2D-HPLC, off-line heart cutting mode) system was developed for the determination of serine (Ser), threonine (Thr) and allo-threonine (aThr) enantiomers in human physiological fluids. Ser, Thr and aThr have a hydroxy group in their side chains, and the development of a simultaneous analytical method with a practically sufficient enantio/chemo-selectivity has been required to clarify their amounts in human physiological fluids. The amino acids in the samples were derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole and were isolated by a reversed-phase column (Singularity RP18, 1.0 x 250 mm) in the first dimension. After the target amino acids were collected, the fractions were manually introduced into an enantioselective column in the second dimension and were detected by their fluorescence. For the second dimension, a Pirkle-type chiral stationary phase (Singularity CSP-013S, 1.5 x 250 mm) was used. The resolution values of the enantiomers obtained by the Singularity CSP-013S column were 7.64 for Ser, 7.58 for Thr and 4.71 for aThr by using the mixture of methanol and acetonitrile containing formic acid as the mobile phases. The developed method was validated and applied to human plasma and urine. In the plasma, the obtained %D values (the percentage of D-form to total amino acid) were 1.7 for Ser, and trace levels of D-aThr and D-Thr were observed. In the urine, the %D values were 48.0 for Ser, 1.6 for Thr and 8.0 for aThr (calculated using D-aThr and L-Thr).

DOI： 10.1016/j.jpba.2022.114807

Web of Science

Scopus

PubMed

researchmap

Repository Public URL： https://hdl.handle.net/2324/7174359

Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Society for Chromatographic Sciences  

<p>A fully-automated two-dimensional (2D) HPLC system for the determination of serine (Ser), threonine (Thr) and <i>allo</i>-threonine (aThr) enantiomers was developed. The system was validated and applied to the determination of the target hydroxy amino acid enantiomers in vinegar samples including the Japanese traditional amber rice vinegar. The Japanese traditional amber rice vinegar is one of the typical natural fermented products containing high levels of D-amino acids, and the clarification of the amounts of hydroxy amino acid enantiomers is expected. For the on-line 2D-HPLC system, a narrowbore ODS column (Singularity RP18, 1.0 x 250 mm) was used in the first dimension, and an originally-designed Pirkle-type chiral stationary phase (Singularity CSP-013S, 1.5 x 250 mm) was utilized in the second dimension. The target hydroxy amino acids were derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) and detected by their fluorescence (ex. 470 nm, em. 530 nm). The concentrations and the %D values were compared among a grain vinegar, a widely-distributed black vinegar and Japanese traditional amber rice vinegars (fermented/aged 1 or 5 years by microorganisms in an earthenware jar). The amounts of hydroxy amino acid enantiomers were low (0.21-0.38 μmol/mL, only L-forms) in the grain vinegar, and relatively high amounts of the L-forms were observed (1.05-1.61 μmol/mL) in the widely-distributed black vinegar. On the other hand, clear peaks of the D-forms (0.16-0.86 μmol/mL for D-Ser, 0.02-0.11 μmol/mL for D-aThr) as well as high amounts of the L-forms (2.27-2.51 μmol/mL for L-Ser, 1.85-2.10 μmol/mL for L-Thr) were observed in the Japanese traditional amber rice vinegars. The amounts of D-Ser and D-aThr clearly increased with increasing the fermentation/aging period. This is the first report showing the profiles of the hydroxy amino acid enantiomers simultaneously, and further investigations using various fermented food/beverage samples are expected. </p>

DOI： 10.15583/jpchrom.2022.006

Web of Science

CiNii Research

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Society for Chromatographic Sciences  

<p>A two-dimensional high-performance liquid chromatographic (2D-HPLC) system using the pre-column derivatization with 4-(<i>N</i>,<i>N</i>-dimethylaminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole (DBD-F) has been developed for the determination of alanine (Ala), aspartic acid (Asp) and serine (Ser) enantiomers. For the precise determination of trace amounts of D-amino acids in complex matrices, a highly sensitive and selective method is required. In the present study, amino acids were derivatized with DBD-F for the sensitive fluorescence detection and were analyzed by a selective 2D-HPLC system combining a reversed-phase column (Singularity RP18, 1.0 x 500 mm) and an enantioselective column (Singularity CSP-001S, 1.5 x 250 mm). The established system was successfully applied to the chiral amino acid analyses of Japanese traditional amber rice vinegar, human plasma and human urine samples. In the Japanese traditional amber rice vinegar and human urine, relatively high amounts of all the target D-amino acids were observed (%D=5.8-37.7), while trace amounts of D-Ser and D-Ala were found in human plasma (%D=0.5-2.1). </p>

DOI： 10.15583/jpchrom.2021.020

Web of Science

CiNii Research

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Methyl groups were introduced on the acridine moiety in chemiluminescent acridinium esters that have electron-withdrawing groups (trifluoromethyl, cyano, nitro, ethoxycarbonyl) at the 4-position on the phenyl ester. The introduction of methyl groups at the 2-, 2, 7-, and 2, 3, 6, 7-positions on the acridine moiety shifted the optimal pH that gave relatively strong chemiluminescence intensity from neutral conditions to alkaline conditions. 4-(Ethoxycarbonyl)phenyl 2, 3, 6, 7, 10-pentamethyl-10λ4-acridine-9- carboxylate, trifluoromethanesulfonate salt showed long-lasting chemiluminescence under alkaline conditions. Acridinium esters to determine hydrogen peroxide concentration at pH 7-10 were newly developed.

DOI： https://doi.org/10.5650/jos.ess21186

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.15583/jpchrom.2021.017

Language：English   Publishing type：Research paper (scientific journal)  

For the enantiomer discriminated determination of lactate (LA) and 3-hydroxybutyrate (3HB) in various complicated samples, a three-dimensional HPLC (3D-HPLC) system has been designed and developed by investigating the separation of the target analytes from unknown substances observed in the real target matrices. LA and 3HB were pre-column derivatized with 4-nitro-7-piperazino-2,1,3-benzoxadiazole for the sensitive fluorescence detection and introduced into the 3D-HPLC system composed of reversed-phase, mixed-mode and enantioselective separations. The present method was validated by calibration curves, precision and accuracy using standard solutions and human samples, and sufficient values were obtained. Using the method, the levels of d-LA, l-LA, d-3Hb and l-3HB were determined, and their concentrations were 9.9, 1004.2, 79.7 and 2.1 μM in the human plasma and 16.0, 86.6, 8.7 and 4.8 μM in the human urine, respectively. The present 3D-HPLC system could selectively determine trace amounts of the target hydroxy acid enantiomers without disturbance of the intrinsic interfering substances in complicated matrices and the applications to various disease samples are expected.

DOI： 10.1016/j.jpba.2020.113871

Language：English   Publishing type：Research paper (scientific journal)  

A two-dimensional (2D) HPLC system focusing on the determination of phenylalanine (Phe) enantiomers in mammalian physiological fluids has been developed. ᴅ-Phe is indicated to have potential values as a disease biomarker and therapeutic molecule in several neuronal and metabolic disorders, thus the regulation of ᴅ-Phe in mammals is a matter of interest. However, the precise determination of amino acid enantiomers is difficult in complex biological samples, and the development of an analytical method with practically acceptable sensitivity, selectivity and throughput is expected. In the present study, a 2D-HPLC system equipped with a reversed-phase column in the 1st dimension and an enantioselective column in the 2nd dimension has been designed, following the fluorescence derivatization of the target amino acid enantiomers with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F). The analytical method was validated using both plasma and urine samples, and successfully applied to human, rat and mouse fluids. Trace levels of ᴅ-Phe were determined in the plasma, and the &#37;ᴅ values were around 0.1&#37; for all species. In the urine, relatively large amounts of ᴅ-Phe were observed, and the &#37;ᴅ values for humans, rats and mice were 3.99, 1.76 and 5.25&#37;, respectively. The relationships between the enzymatic activity of ᴅ-amino acid oxidase (DAO) and the amounts of intrinsic ᴅ-Phe have also been clarified, and high ᴅ-Phe amounts were observed (around 0.3&#37; in the plasma and around 50&#37; in the urine) in the DAO deficient rats and mice.

DOI： 10.1016/j.bbapap.2020.140540

Language：English   Publishing type：Research paper (scientific journal)  

Methoxycarbonylphenyl 10-methyl-10λ4-2,7-disubstituted acridine-9-carboxylate derivatives were synthesized, and both their chemiluminescence intensities at pH 7−10 and their chemical stabilities were clarified. The products and generation efficiency of the chemiluminescence reactions were evaluated. 4-(Methoxycarbonyl)phenyl 10-methyl-10λ4-2,7-dimethylacridine-9-carboxylate gave relatively strong chemiluminescence intensities at pH 7−10 and was applied to the measurement of hydrogen peroxide.

DOI： 10.1016/j.jphotochem.2020.112851

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.15583/jpchrom.2020.015

Language：English   Publishing type：Research paper (scientific journal)  

A three-dimensional (3D) HPLC system in combination with fluorescence derivatization has been developed for the highly sensitive and selective analysis of chiral amino acids in extraterrestrial samples. As the targets, alanine (Ala), 2-aminobutyric acid (2AB), valine (Val), norvaline (nVal) and isovaline (iVal), frequently found chiral amino acids in the carbonaceous chondrites, were selected. These amino acids were pre-column derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F), and the target analytes were separated from other amino acids and organic compounds by a reversed-phase column in the first dimension. The targets were further separated from interferences by an anion-exchange column in the second dimension, and their enantiomers were separated and determined in the third dimension by a Pirkle-type enantioselective column. The present 3D-HPLC system was validated and applied to the Murchison meteorite and the Antarctic meteorites, and all of the target amino acid enantiomers were clearly observed (0.78-22.33 nmol/g in the Murchison meteorite and 1.79-78.84 nmol/g in the Antarctic meteorites) without severe interferences. The &#37;L values of the non-proteinogenic amino acids were almost 50&#37; in both meteorites, and even the proteinogenic amino acids were almost racemic in the Antarctic meteorites.

DOI： 10.1016/j.chroma.2020.461255

Language：English   Publishing type：Research paper (scientific journal)  

2,4-Disubstituted phenyl 10-methyl-10 lambda(4)-acridine-9-carboirylate derivatives were synthesized and the chemiluminescence of each was measured at pH 6-9. The introduction of electron-withdrawing groups at 2,4-positions in the phenyl moiety intensified chemiluminescence. 2,4-(Dimethoxycarbonyl)phenyl 10-methyl-10 lambda(4)-acridine-9-carboxylate trifluoromethanesulfonate salt produced long-lasting chemiluminescence emission, showed maximum chemiluminescence intensities at pH 8 and was used in simple chemiluminescence assays of hydrogen peroxide and choline under neutral conditions. The linear calibration range and detection limit of choline at pH 8 were 0.1-1000 mu M and 0.01 mu M, respectively.

DOI： 10.1016/j.dyepig.2019.107628

Language：English   Publishing type：Research paper (scientific journal)  

The concentrations of several d-amino acids have been reported to significantly increase in the plasma of patients with chronic kidney disease (CKD). However, the amounts of these d-amino acids are low (around 1% of the l-form or lower), and their analyses were complicated by various interfering compounds in many clinical samples. A highly selective analytical method is thus required to perform the accurate and precise determination of these d-amino acids in the plasma of CKD patients. In the present study, a selective 3D-HPLC system equipped with reversed-phase, anion-exchange, and enantioselective columns has been designed and developed for the determination of the asparagine, serine, alanine and proline enantiomers. For the sensitive analysis, amino acids were precolumn derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole and detected by their fluorescence. The system was validated by using human plasma in addition to the standard amino acids, and results with a sufficient linearity, precision, and accuracy were obtained. The 3D-HPLC system was applied to the plasma of patients with different stages of CKD and all of the target d-amino acids were clearly observed without interferences for all 25 tested patients. Good correlations were shown between the kidney function of the patients and the %d values of the target analytes, especially d-Asn and d-Ser, indicating that the present 3D-HPLC method is useful for the sensitive diagnosis of CKD.

DOI： 10.1021/acs.analchem.9b01615

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.15583/jpchrom.2019.011

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.15583/jpchrom.2018.021

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.15583/jpchrom.2018.019

Language：English   Publishing type：Research paper (scientific journal)  

An automated two-dimensional HPLC-MS/MS system was designed and developed for the highly selective determination of trace levels of d-amino acids. As the targets, frequently observed ones in mammalian physiological fluids, Ala, Asp, Glu, Leu, Pro and Ser, were selected because these d-amino acids are the potential biomarkers for the early and sensitive diagnoses of various diseases. The target analytes were derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F), then isolated by a reversed-phase column in the first dimension. The NBD-amino acid fractions were automatically collected into the multi-loop device, and introduced into the enantioselective column in the second dimension to separate the d- and l-forms followed by detection by an MS/MS. The obtained resolution values of the enantiomers were 1.87-5.17 and the calibration lines, precision and accuracy were practically sufficient. By using the present 2D HPLC-MS/MS system, trace levels of d-amino acids in complex biological matrices were determined without disturbance by the intrinsic interfering compounds, and successfully applied to the analysis of the human clinical samples (plasma and urine).

DOI： 10.1016/j.chroma.2018.07.076

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.15583/jpchrom.2018.007

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.15583/jpchrom.2018.002

Language：English   Publishing type：Research paper (scientific journal)  

For the enantioselective and simultaneous analysis of lactate and 3-hydroxybutyrate, a validated online two-dimensional high-performance liquid chromatography system using 4-nitro-7-piperazino-2,1,3-benzoxadiazole as a fluorescent derivatization reagent has been developed. For the reversed-phase separation in the first dimension, a Capcell Pak C18 ACR column (1.5 × 250 mm, particle size 3 μm) was used, and the target fractions were isolated by their hydrophobicity. In the second dimension, a polysaccharide-coated enantioselective column, Chiralpak AD-H (2.0 × 250 mm, 5 μm), was used. The system was validated by the calibration curve, intraday precision, interday precision, and accuracy using standards and real human samples, and satisfactory results were obtained. The present method was applied to human plasma and urine, and in the plasma, trace amounts of d-lactate (8.4 μM) and l-3-hydroxybutyrate (1.0 μM), besides high levels of l-lactate (860.9 μM) and d-3-hydroxybutyrate (59.4 μM), were successfully determined. In urine, trace levels of d-lactate (3.7 μM), d-3-hydroxybutyrate (2.3 μM), and l-3-hydroxybutyrate (3.3 μM) in addition to a relatively large amount of l-lactate (15.4 μM) were observed. The present online two-dimensional high-performance liquid chromatography system is useful for the simultaneous determination of all the lactate and 3-hydroxybutyrate enantiomers in human physiological fluids, and further clinical applications are ongoing.

DOI： 10.1002/jssc.201701283

Language：English   Publishing type：Research paper (scientific journal)  

Effect of aryl substituents on intramolecular cyclizations of 3,3',5,5'-tetraaryl-2,2'-biphenoquinones (Ar = phenyl (1a) and 4-methoxyphenyl (1b)) has been studied. In benzene, 1a gave 2,4,6,8-tetraphenyldibenzofuran-1-ol (10) gradually as a main product, indicating the phenyl substituents preferred to stabilize the intermediate by delocalization of the negative charge rather than that of the positive one. In contrast, the reaction of 1b occurred spontaneously in order to give a complex mixture, which should be due to 4-methoxyphenyl substituent at the 3 position.

DOI： 10.3987/COM-08-S(D)57

Language：English   Publishing type：Research paper (scientific journal)  

Dual fluorescent compounds are useful platforms for the development of ratiometric probes and sensors. We have developed a new series of dual fluorescent compounds, 1-aryl-substituted 6-methoxy-4-quinolones, and investigated their structural and photophysical properties. The X-ray crystallographic analysis and ab initio quantum chemical calculations revealed that the developed compounds exhibited 60-75 degrees twisted structures. The dual fluorescence of the compounds were observed in polar solvents, and the ratiometric fluorescence responses to alterations in the acidity and temperature were obtained. Copyright (C) 2008 John Wiley & Sons, Ltd.

DOI： 10.1002/bio.1044

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

As photo-reactive precursors of high-spin organic compounds sterically separated from surroundings by bulky peripheral groups, diphenyldiazomethane derivatives substituted by tetrakis{3,5-bis(benzyloxy)benzyloxy} groups 1, by tetrakis[3,5-bis{3′,5′-bis(benzyloxy)benzyloxy}bezyloxy] groups 2, and nonakisdiazo compound associated with ferromagnetic spin couplers substituted by dodecakis{3,5-bis(benzyloxy)benzyloxy} groups 3, were prepared and their magnetic properties after irradiation in their own condensed films were investigated. Field dependences of magnetization and temperature dependences of χT value after irradiation of 1 and 2 clearly exhibited that spin centers i.e., diphenylcarbene parts of 1 and 2 were magnetically isolated from surrounding molecules each other by steric hindrance of the peripheral bulk substituents even in the neat films. In the case of 3, some part of molecules interacted antiferromagnetically with neighboring molecules but a fatal strong antiferromagnetic interaction was also avoided.

DOI： 10.1016/j.poly.2005.03.067

Language：English   Publishing type：Research paper (scientific journal)  

The title compound, 6-methoxy-4-quinolone (3), was synthesized by the oxidation of 5-methoxyindole-3-acetic acid (2), and its crystal structure was determined by X-ray diffraction analysis. The compound crystallized in the monoclinic system, space group P21/n, with cell parameters of a = 4.547(2)Å, b = 16.328(8)Å, c = 13.731(4)Å, β = 92.38(2)°, and Z = 4. The final residual factor was 0.064. 2005

DOI： 10.2116/analscix.21.x45

Language：English   Publishing type：Research paper (scientific journal)  

The crystal structure of N-[(6-methoxy-4-oxo-1,4-dihydroquinolin-3-yl)methyl]-2,2-dimethylpropanamide (2) was determined by X-ray diffraction analysis. The compound crystallized in the triclinic system, space group P1, with cell parameters of a = 7.829(3)Å, b = 8.995(4)Å, c = 10.646(5)Å, α = 85.86(2)o, β = 86.99(1)o, γ = 88.00(2)o, and Z = 2. The structure was refined by full-matrix least-squares to final values of R1 = 0.049 and wR2 = 0.103. The intermolecular hydrogen bonds of the type N-H···O were observed in the structure. 2004

DOI： 10.2116/analscix.20.x115

Language：English   Publishing type：Research paper (scientific journal)  

Ab initio total energy calculations with the DFT framework based on the geometries obtained by X-ray data were carried out for five complexes composed by copper(II) ion and organic radicals (eg. aminoxyl and carbene) through pyridine, bipyridine and terpyridine rings. It was found that the copper(II) complex having radical substituted at 4-position of aromatic ligand favors ferromagnetic coupling between organic radical and paramagnetic copper(II) ion.

DOI： 10.1080/10587250210747

Language：English   Publishing type：Research paper (scientific journal)  

In order to achieve a pure organic high-spin molecule, poly(m-phenyleneethynylene) derivative 1 having diazo groups and nitronyl nitroxide moieties alternately were designed. Its three model compounds, diphenylacetylene derivative 2, bis(phenylethynyl)benzene derivative 3, and oligomeric compound 4 having partial structure of 1 have been prepared by the coupling reaction of ethynyl derivatives of phenylnitronylnitroxide and iodo derivatives of diphenyldiazomethane. Field dependence of magnetization after irradiation of 2 and 3 in frozen solutions suggested that the photo-generated species have quartet and quintet ground states with J/k(B), values of + 1.75 and + 1.09 K, respectively. However, spin interaction between carbene and nitronylnitroxide through 3,3-diphenylacetylene moiety is not strong enough to form high-spin chain having long correlation length for 4. (C) 2001 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0277-5387(01)00638-6

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

The association of phenylboronic acid (no unpaired electron, compound 1) with the free radical phenyl nitronyl nitroxide (PNN, S = 1/2 , compound 2) constitutes an interheteromolecular hydrogen bonding system displaying ferromagnetic intermolecular interactions. We have investigated its spin density distribution to visualize the pathway of these magnetic interactions. This complex crystallizes at room temperature in the monoclinic space group P2₁/n. The unit cell includes one pair (1 + 2). The molecule (1) bridges two radicals (2) by hydrogen bonds OH···ON: the two different hydrogen bond lengths are quite similar (1.95 and 1.92 Å). Infinite chains of this run along the b-axis. In this structure the methyl groups of the PNN are randomly distributed in two different configurations. Below T = 220 K the compound undergoes a crystallographic phase transition due to the ordering of these methyl groups. We have determined the low-temperature structure using both X- ray and neutron diffraction. The new space group is P1̄. The global structure is preserved and infinite chains still run along the b-axis, but the unit cell now comprises two different pairs (1 + 2) instead of one, with four different hydrogen bond OH···ON distances: 1.96 and 1.84 Å for the first pair, 1.96 and 1.91 Å for the second pair. The spin density of this complex was measured at T = 1.8 K (H = 4.6 T) by polarized neutron diffraction. The data were treated using both maximum entropy approach and wave function modeling. As in the isolated PNN, the main part of the spin density is located on the O-N-C-N-O fragment of each radical in the unit cell. However, compared to the isolated case, a significant difference exists: a large unbalance is observed between the two oxygen atoms of each radical. Moreover, a positive contribution is found on the two hydrogen atoms involved on the OH···ON hydrogen bonds of each phenylboronic acid molecule. The stronger contribution corresponds to the longer hydrogen bonds. On the radical the stronger reduction is observed on the oxygen atoms involved in the shorter hydrogen bonds. The experimental results are compared to those obtained by density functional theory (DFT) calculations: on the whole, the experimental effects have been reproduced. However, if there is a good qualitative agreement, from the quantitative point of view, the DFT results are still very far from the experimental ones.

DOI： 10.1021/ja991042u

Language：English   Publishing type：Research paper (scientific journal)  

The association of phenylboronic acid (no unpaired electron) with the free radical phenyl nitronyl nitroxide (S = 1/2) constitutes an inter-heteromolecular hydrogen bonding system presenting ferromagnetic intermolecular interactions. We have investigated its spin density distribution in order to visualize the pathway of these magnetic interactions. The spin density of this complex was measured by polarized neutron diffraction. The data were treated using both direct and indirect methods. As in the isolated PNN, the main part of the spin density is located on the O-N-C-N-O fragment of the PNN radical. But, with the PNNB, the global spin density distribution give evidences that the phenylboronic acid constitutes a spin transmission path between PNN radicals via hydrogen bonds. The experimental results are compared to those obtained by density functional theory calculations.

DOI： 10.1080/10587259908023319

Language：English   Publishing type：Research paper (scientific journal)  

Two kinds of 1:1 manganese complexes a and b of bis(hexafluoroacetylacetonato)manganese(II) coordinated with diazodi(4- pyridyl)methane (1) were prepared. Complexes a and b crystallize in the orthorhombic space group Pbca and in monoclinic C2/c, respectively. Two pyridyl nitrogen atoms from two different molecules of 1 are coordinated in the cis and trans configurations to the manganese ion to form helical and zigzag infinite chains of octahedral manganese complexes in complexes a and b, respectively. The magnetic susceptibilities (χmol) of both crystals before and after irradiation were measured on a SQUID susceptometer and revealed χ(mol)T vs T plots characteristic of ferrimagnetic chains after irradiation for 97 h; interaction between the manganese(II) ion and the photogenerated carbene is antiferromagnetic in both complexes. The antiferromagnetic exchange coupling parameters (J) in the photolyzate of complex a and b were estimated by a theoretical treatment through a procedure of extrapolation by using small rings to be J/k(B) = -34.8 ± 0.8 and -24.4 ± 0.5 K, respectively. Maximum χ(mol)T values of 210 at 5 K for cis- and 246 emu·K·mol^-1 at 1.9 K for trans complexes correspond to correlation lengths of 186 and 218 manganese-carbene S = 3/2 units, respectively.

DOI： 10.1021/ja981293n

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

Two crystalline complexes, the complex of p-fluorophenylboronic acid with phenyl nitronyl nitroxide (2) and the complex of p-nitrophenylboronic acid with p-dimethylaminophenyl nitronyl nitroxide (3), were prepared. Both of those complexes as well as the complex of phenylboronic acid with phenyl nitronyl nitroxide (1) exhibit ferromagnetic spin interactions (1: J/k_B=+0.65 K, 2: J/k_B=+0.58 K, 3: J/k_B=+1.35 K). The results are discussed based on the X-ray crystal structure.

DOI： 10.1080/10587259708044574

Language：English   Publishing type：Research paper (scientific journal)  

A stable pentaradical, N,N-bis(4-methoxy-3,5-bis(N-tert-butyl-N-oxyamino)phenyl)]aminoxyl, is prepared and its ground state determined to be a sextet (S = 5/2) by SQUID magnetization measurements of the pentaradical diluted in poly(vinyl chloride) matrix.

DOI： 10.1039/a704160h

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/adma.19970090414

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

A crystalline molecular complex derived from phenyl nitronyl nitroxide (1) and phenyl boronic acid (2) exhibits a ferromagnetic spin interaction (J= +0.65 K) below 30 K: An X-ray analysis revealed the crystal structure constituted of one-dimensional array of two component molecules linked alternately by the NO-HO-B hydrogen bonds. The NO-HO-B-OH - ON linkage was suggested to act as a path for ferromagnetic spin coupling. An unusual formation of nitrosonium salt (3) was found in the reaction of 1 and BF₃. Its molecular and crystal structures were determined.

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

Diradical species 1N, 1I, 2N, and 2I, in which two nitronyl nitroxide (N) or imino nitroxide (I) radical centers are attached to thieno[23-b]thiophene (1) and thieno[23-b]thieno[3' 2' -d]thiophene (2) chromophores, respectively, were prepared and their intramolecular exchange interactions were investigated in frozen solutions by means of ESR spectroscopy and magnetic susceptibility measurements at cryogenic temperature. Temperature dependence of the ESR signal intensities due to the triplet state revealed that bis(nitronyl nitroxide) radicals, 1N and 2N, are ground-state singlet species with quite small singlet-triplet gaps. In bis(imino nitroxide) radical 1I the spin interaction was antiferromagnetic and the singlet-triplet gap was estimated to be 2J/k_B= -18 K. On the other hand, bis(imino nitroxide) 21 was revealed to be a singlet-triplet degenerate species. These results are discussed in terms of the intramolecular NO - S contact along with corroboration by the semi-empirical MO calculations.

DOI： 10.1016/0040-4020(96)00324-9

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

A crystalline molecular complex derived from phenyl nitronyl nitroxide and phenylboronic acid exhibits a ferromagnetic spin interaction (J = +0.65 K) below 30 K: X-ray analysis reveals the crystal structure to be constituted of a one-dimensional array of two component molecules linked alternately by the NO ⋯ HOB hydrogen bond.

DOI： 10.1039/C39950001861

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

Diradical species which bear two nitronyl nitroxide groups or two imino nitroxide groups on thieno[3,2-b]thiophene and thieno[2,3-b]thiophene, respectively, were studied in a frozen solution by means of ESR spectroscopy to show those are the ground-state singlet species.

DOI： 10.1016/00404-0399(50)1047L-

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

Nitronyl nitroxide (ONC=NO) and imino nitroxide (NCNO) free radicals joined to isomeric thieno-[3,2-b]thiophene and thieno[2,3-b]thiophene, respectively, were prepared and their crystal structures and magnetic properties were investigated. In all crystals of four free radical species, the ON-C-NO moieties are in the same plane as the thienothiophene ring. The coplanarity is associated with the extremely short intramolecular contact between the oxygen atom in the NO group and the sulfur atom in the thienothiophene ring. The free radicals attached to thieno[3,2-b]thiophene are arranged in a chain structure with short intermolecular NO-S contacts, while the free radicals linked to thieno[2,3-b]thiophenes make dimers with a face-to-face pairing by the use of the NO-S contacts. Among four radical species, thieno[3,2-b]thiophene-substituted nitronyl nitroxide exhibits a weak ferromagnetic interaction (J = +0.11 K/k_B, H = -2JS_iS_j) below 40 K as revealed by a SQUID susceptometer, while others are antiferromagnetic.

Event date： 2024.10

Language：English   Presentation type：Oral presentation (general)  

Venue：Dalian   Country：China  

Event date： 2024.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Geneva   Country：Switzerland  

Event date： 2024.8

Language：Japanese  

Venue：誌上開催  

Event date： 2024.8

Language：Japanese  

Venue：誌上開催  

Event date： 2024.8

Language：English  

Venue：Kanazawa, JAPAN  

Event date： 2024.8

Language：English  

Venue：Kanazawa, JAPAN  

Event date： 2024.8

Language：English  

Venue：Kanazawa, JAPAN  

Event date： 2024.8

Language：English  

Venue：Kanazawa, JAPAN  

Event date： 2024.8

Language：English  

Venue：Kanazawa, JAPAN  

Event date： 2024.8

Language：English  

Venue：Kanazawa, JAPAN  

Event date： 2024.8

Language：English  

Venue：Kanazawa, JAPAN  

Event date： 2024.8

Language：English  

Venue：Kanazawa, JAPAN  

Event date： 2024.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Kanazawa, JAPAN  

Event date： 2024.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北九州   Country：Japan  

Event date： 2024.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北九州   Country：Japan  

Event date： 2024.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北九州   Country：Japan  

Event date： 2024.6

Event date： 2024.6

Event date： 2024.6

Event date： 2024.6

Event date： 2024.6

Event date： 2024.6

Event date： 2024.6

Event date： 2024.6

Event date： 2024.6

Event date： 2024.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜   Country：Japan  

Event date： 2024.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜   Country：Japan  

Event date： 2024.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜   Country：Japan  

Event date： 2024.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：横浜   Country：Japan  

Event date： 2023.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Event date： 2023.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Event date： 2023.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：長岡   Country：Japan  

Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：長岡   Country：Japan  

Event date： 2023.7

Language：Japanese  

Venue：札幌   Country：Japan  

Event date： 2023.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：札幌   Country：Japan  

Event date： 2023.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：札幌   Country：Japan  

Event date： 2023.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：札幌   Country：Japan  

Event date： 2023.7

Language：Japanese   Presentation type：Poster presentation  

Venue：札幌   Country：Japan  

Event date： 2023.7

Language：English   Presentation type：Oral presentation (general)  

Venue：Ankara   Country：Turkey  

Event date： 2023.7

Language：English   Presentation type：Oral presentation (general)  

Venue：Ankara   Country：Turkey  

Event date： 2023.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岐阜   Country：Japan  

Event date： 2023.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岐阜   Country：Japan  

Event date： 2023.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岐阜   Country：Japan  

Event date： 2023.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岐阜   Country：Japan  

Event date： 2023.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岐阜   Country：Japan  

Event date： 2023.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Dusseldorf   Country：Germany  

Event date： 2023.6

Language：English  

Venue：Dusseldorf   Country：Germany  

Event date： 2023.6

Language：English  

Venue：Dusseldorf   Country：Germany  

Event date： 2023.6

Language：English  

Venue：Dusseldorf   Country：Germany  

Event date： 2023.6

Language：English  

Venue：Dusseldorf   Country：Germany  

Event date： 2023.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山   Country：Japan  

Event date： 2023.3

Language：English   Presentation type：Oral presentation (general)  

Venue：北海道大学（札幌市）   Country：Japan  

Event date： 2023.3

Language：Japanese  

Venue：北海道大学（札幌市）   Country：Japan  

Event date： 2023.3

Language：Japanese  

Venue：北海道大学（札幌市）   Country：Japan  

Event date： 2023.3

Language：Japanese  

Venue：北海道大学（札幌市）   Country：Japan  

Event date： 2023.3

Language：Japanese  

Venue：北海道大学（札幌市）   Country：Japan  

Event date： 2023.3

Language：Japanese  

Venue：北海道大学（札幌市）   Country：Japan  

Event date： 2022.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2022.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2022.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2022.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2022.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2022.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山市   Country：Japan  

Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.9

Language：English   Presentation type：Oral presentation (general)  

Venue：University of Mons (Belgium)   Country：Belgium  

Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：日本大学（船橋市）   Country：Japan  

Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：日本大学（船橋市）   Country：Japan  

Event date： 2022.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.7

Language：English   Presentation type：Oral presentation (general)  

Venue：Urbana IL   Country：United States  

Event date： 2022.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：石垣市民会館（石垣市）   Country：Japan  

Event date： 2022.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：石垣市民会館（石垣市）   Country：Japan  

Event date： 2022.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：石垣市民会館（石垣市）   Country：Japan  

Event date： 2022.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：石垣市民会館（石垣市）   Country：Japan  

Event date： 2022.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：石垣市民会館（石垣市）   Country：Japan  

Event date： 2022.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：石垣市民会館（石垣市）   Country：Japan  

Event date： 2022.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：石垣市民会館（石垣市）   Country：Japan  

Event date： 2022.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：石垣市民会館（石垣市）   Country：Japan  

Event date： 2022.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：石垣市民会館（石垣市）   Country：Japan  

Event date： 2022.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：石垣市民会館（石垣市）   Country：Japan  

Event date： 2022.6

Language：English   Presentation type：Oral presentation (general)  

Venue：石垣市民会館（石垣市）   Country：Japan  

Event date： 2022.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Online   Country：Japan  

Event date： 2021.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：野田   Country：Japan  

Event date： 2021.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：野田   Country：Japan  

Event date： 2021.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：野田   Country：Japan  

Event date： 2021.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：石垣   Country：Japan  

Event date： 2021.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：石垣   Country：Japan  

Event date： 2021.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：石垣   Country：Japan  

Event date： 2021.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：石垣   Country：Japan  

Event date： 2021.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：石垣   Country：Japan  

Event date： 2021.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都   Country：Japan  

Event date： 2021.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都   Country：Japan  

Event date： 2021.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.8 - 2021.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

Event date： 2021.8 - 2021.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

Event date： 2021.8 - 2021.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

Event date： 2021.8 - 2021.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

Event date： 2021.8 - 2021.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

Event date： 2021.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2020.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：静岡   Country：Japan  

Event date： 2020.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：静岡   Country：Japan  

Event date： 2020.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：静岡   Country：Japan  

Event date： 2020.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：静岡   Country：Japan  

Event date： 2020.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：静岡   Country：Japan  

Event date： 2020.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：静岡   Country：Japan  

Event date： 2020.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：静岡   Country：Japan  

Event date： 2020.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：静岡   Country：Japan  

Event date： 2020.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：静岡   Country：Japan  

Event date： 2020.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：誌上開催   Country：Japan  

Event date： 2020.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：誌上開催   Country：Japan  

Event date： 2020.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：誌上開催   Country：Japan  

Event date： 2020.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：誌上開催   Country：Japan  

Event date： 2020.6

Language：English  

Venue：Bangkok   Country：Thailand  

Event date： 2020.6

Language：English  

Venue：Bangkok   Country：Thailand  

Event date： 2020.6

Language：English  

Venue：Bangkok   Country：Thailand  

Event date： 2020.6

Language：English  

Venue：Bangkok   Country：Thailand  

Event date： 2020.6

Language：English  

Venue：Bangkok   Country：Thailand  

Event date： 2020.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都   Country：Japan  

Event date： 2019.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Kyoto   Country：Japan  

Event date： 2019.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都   Country：Japan  

Event date： 2019.12

Language：Japanese  

Venue：Kyoto   Country：Japan  

Event date： 2019.12

Language：Japanese  

Venue：Kyoto   Country：Japan  

Event date： 2019.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Tokyo   Country：Japan  

Event date： 2019.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Tel-Aviv   Country：Israel  

Event date： 2019.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Tokyo   Country：Japan  

Event date： 2019.9

Language：English   Presentation type：Oral presentation (general)  

Venue：Tokyo   Country：Japan  

Event date： 2019.7

Language：English   Presentation type：Oral presentation (general)  

Venue：Bordeaux   Country：France  

Event date： 2019.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北九州   Country：Japan  

Event date： 2019.6

Language：English  

Venue：Milan   Country：Italy  

Event date： 2018.9

Language：English  

Venue：Shiga   Country：Japan  

Event date： 2018.9

Language：English  

Venue：Leuven   Country：Belgium  

Event date： 2018.9

Language：English  

Venue：Leuven   Country：Belgium  

Event date： 2018.8 - 2018.9

Language：English  

Venue：Kyoto   Country：Japan  

Event date： 2018.7 - 2018.8

Language：English  

Venue：Washington, DC   Country：United States  

Event date： 2018.7 - 2018.8

Language：English  

Venue：Washington, DC   Country：United States  

Event date： 2017.11

Language：English  

Venue：Jeju   Country：Korea, Republic of  

Event date： 2017.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Jeju   Country：Japan  

Event date： 2017.11

Language：English  

Venue：Jeju   Country：Korea, Republic of  

Event date： 2017.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Prague   Country：Czech Republic  

Event date： 2017.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台   Country：Japan  

Event date： 2017.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台   Country：Japan  

Event date： 2016.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Taipei   Country：Taiwan, Province of China  

Event date： 2016.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Taipei   Country：Taiwan, Province of China  

Event date： 2013.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

反応を磁場で制御する試みは以前より行われているが、一般的な反応に広範に応用が可能な方法論については未だに確立されていない。そこで今回、超常磁性酸化鉄ナノパーティクル（SPION）の表面保護ポリマーにそれぞれ反応が可能な官能基を導入した二種類のSPIONを用い、磁場によりSPION間の距離をコントロールすることにより反応を制御することを試みた。

Event date： 2012.3

Presentation type：Oral presentation (general)  

Venue：慶応大学日吉キャンパス   Country：Japan  

パラジウム触媒を表面に導入した超常磁性鉄酸化物ナノパーティクル（SPION）1を合成し、これを用いて、ブテニルエーテルを介してフルオレセイン誘導体を導入したSPION 2からの蛍光分子の放出反応について検討を行った。

Event date： 2011.9

Presentation type：Oral presentation (general)  

Venue：つくば国際会議場   Country：Japan  

超常磁性酸化鉄ナノパーティクルは近年、ドラッグデリバリーシステム（DDS）やMRI造影剤等の生体内イメージング剤への応用が期待され、盛んに研究が行われている。その際にSPION表面への機能性分子の導入と、生体内環境や外部からの刺激による機能性分子の選択的な放出の機構が重要となる。本研究では機能分子のモデルとしてフルオレセイン誘導体及びニトロフェノールを用い、アミノブテニルリンカーを通した機能性分子の表面保護部への導入と、Pd(0)によるアリールエーテル部位の切断反応を用いた選択的放出反応について検討を行った。

Event date： 2020.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都   Country：Japan  

Event date： 2020.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都   Country：Japan  

Event date： 2020.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都   Country：Japan  

Event date： 2020.2

Language：Japanese  

Country：Japan  

Event date： 2020.2

Language：Japanese  

Venue：Toyama   Country：Japan  

Event date： 2020.2

Language：Japanese  

Venue：富山   Country：Japan  

Event date： 2020.2

Language：Japanese  

Venue：富山   Country：Japan  

Event date： 2020.2

Language：Japanese  

Country：Japan  

Event date： 2020.2

Language：Japanese  

Country：Japan  

Event date： 2019.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都   Country：Japan  

Event date： 2019.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都   Country：Japan  

Event date： 2019.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2019.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大津   Country：Japan  

Event date： 2019.8

Language：Japanese  

Venue：西東京   Country：Japan  

Event date： 2019.8

Language：Japanese  

Venue：西東京   Country：Japan  

Event date： 2019.7

Language：English   Presentation type：Oral presentation (general)  

Venue：Bordeaux   Country：France  

Event date： 2019.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：金沢   Country：Japan  

Event date： 2019.7

Language：Japanese  

Venue：唐津   Country：Japan  

Event date： 2019.7

Language：Japanese  

Venue：唐津   Country：Japan  

Event date： 2019.7

Language：Japanese  

Venue：唐津   Country：Japan  

Event date： 2019.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北九州   Country：Japan  

Event date： 2019.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北九州   Country：Japan  

Event date： 2019.6

Language：English   Presentation type：Oral presentation (general)  

Venue：岡山   Country：Japan  

Event date： 2019.6

Language：Japanese  

Venue：岡山   Country：Japan  

Event date： 2019.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北九州   Country：Japan  

Event date： 2019.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北九州   Country：Japan  

Event date： 2019.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北九州   Country：Japan  

Event date： 2019.3

Language：English   Presentation type：Oral presentation (general)  

Venue：Bangkok   Country：Thailand  

Event date： 2019.3

Language：English   Presentation type：Oral presentation (general)  

Venue：Bangkok   Country：Thailand  

Event date： 2019.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：千葉   Country：Japan  

Event date： 2019.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：札幌   Country：Japan  

Event date： 2019.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：千葉   Country：Japan  

Event date： 2019.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：千葉   Country：Japan  

Event date： 2018.11

Language：Japanese  

Venue：豊橋   Country：Japan  

Event date： 2018.11

Language：Japanese  

Venue：豊橋   Country：Japan  

Event date： 2018.11

Language：Japanese  

Venue：豊橋   Country：Japan  

Event date： 2018.11

Language：Japanese  

Venue：豊橋   Country：Japan  

Event date： 2018.11

Language：English  

Venue：豊橋   Country：Japan  

Event date： 2018.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本   Country：Japan  

Event date： 2018.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本   Country：Japan  

Event date： 2018.7

Language：English   Presentation type：Oral presentation (general)  

Venue：Dalian   Country：China  

Event date： 2018.7

Language：English   Presentation type：Oral presentation (general)  

Venue：Dalian   Country：China  

Event date： 2018.6 - 2019.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：弘前   Country：Japan  

Event date： 2018.6 - 2019.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：弘前   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：金沢   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：金沢   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：金沢   Country：Japan  

Event date： 2018.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：金沢   Country：Japan  

Event date： 2017.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都   Country：Japan  

Event date： 2017.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都   Country：Japan  

Event date： 2017.11

Language：Japanese  

Venue：京都   Country：Japan  

Event date： 2017.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2017.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京大学（東京）   Country：Japan  

Event date： 2017.7

Language：Japanese  

Venue：朝倉   Country：Japan  

Event date： 2017.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：朝倉   Country：Japan  

Event date： 2017.7

Language：English   Presentation type：Oral presentation (general)  

Venue：朝倉   Country：Japan  

Event date： 2016.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Taipei   Country：Taiwan, Province of China  

Language：Japanese  

Country：Japan  

Synthesis and ESR Studies of Thienothiophene Derivatives with two Radicals Centers.

Language：Japanese  

Country：Japan  

二つのラジカル中心を持つチエノチオフェン環化合物の磁気的性質

Language：Japanese  

Country：Japan  

Photochemical Generation of a Stable Triplet Radical Pair in the Solid‐dtate.

Language：Japanese  

Country：Japan  

Spin Interactions through the NO...S Contacts of the Nitroxide Radicals Incorporated in Thienothiophene.

Language：Japanese  

Country：Japan  

Complexation of Nitroxide Radicals with Boron Compounds and their Magnetic Properties.

Language：Japanese  

Country：Japan  

チオフェン縮環体をスピンカップラーとするビラジカルのスピン伝達

Language：Japanese  

Country：Japan  

Magnetic Propaties of Phenylboronic Acid Derivatives bearing Nitronyl Nitroxide Radical Unit.

Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：北九州   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：Fukuoka   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：富山   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：西宮   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：仙台   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：Tsukuba   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：神奈川   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：神奈川   Country：Japan  

Magnetic properties in condensed film and in frozen solution
after irradiation of polydiazo dendrimer having bulk peripheral groups

Presentation type：Oral presentation (general)  

Venue：大阪   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：大阪   Country：Japan  

Preparation and magnetic properties of dendritic superhigh-spin organic compounds
bearing various peripheral groups

Presentation type：Oral presentation (general)  

Venue：Honolulu   Country：United States  

Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Language：Japanese   Presentation type：Poster presentation  

Language：Japanese   Presentation type：Oral presentation (general)  

Language：Japanese   Presentation type：Oral presentation (general)  

Language：Japanese  

Language：Japanese  

Language：Japanese  

Language：Japanese  

Language：Japanese  

Language：Japanese  

Language：Japanese  

Language：Japanese   Presentation type：Oral presentation (general)  

Language：Japanese  

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：2

Number of peer-reviewed articles in Japanese journals：0

Proceedings of International Conference Number of peer-reviewed papers：0

Proceedings of domestic conference Number of peer-reviewed papers：0

Type：Competition, symposium, etc. 

Number of participants：300

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Number of participants：300

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc.