caa a22 4500 605545421 CHVBK 20210128100936.0 cr unu---uuuuu 210128e20150901xx s 000 0 eng 10.1007/s00723-015-0664-5 doi (NATIONALLICENCE)springer-10.1007/s00723-015-0664-5 Quantitative Spin-trapping ESR Investigation of Alkoxyl Radical Derived from AAPH: Development of a Flow-injection Spin-trapping ESR System for the Oxygen Radical Absorbance Capacity Assay [Elektronische Daten] [Akira Nakajima, Tomoko Yamaguchi, Tomoyuki Yamashita, Kiyoshi Kawai, Yusuke Miyake, Kenji Kanaori, Kunihiko Tajima] A flow-injection electron spin resonance (ESR) system was developed for the quantitative detection of an alkoxyl radical (RO·, R=C(CH3)2-C(+NH2Cl−)NH2) derived from AAPH (2,2′-azobis(2,4-amidinopropane) dihydrochloride) by thermal decomposition. Optimal measurement conditions for the system were examined, and it was found that the control of the radical formation by quenching in an ice-water vessel should be effective to obtain the stable and accurate results. The system was applied for the estimation of the alkoxyl radical-elimination ability and the oxygen radical absorbance capacity values of selected biosubstances, such as Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), caffeic acid, 4-hydroxycinnamic acid, epinephrine, rutin, (+)-catechin, l-tryptophane, and d-mannitol. As the rate constant for the reaction between alkoxyl radical and substrate, k S, could not be unequivocally determined, the defined value, γ 50=k S/k 1, (k 1, the rate constant for the reaction between alkoxyl radical and spin trap) was used as a reaction parameter of substrate for alkoxyl radical. The flow-injection electron spin resonance system using alkoxyl radical elimination gave valid γ 50 values for biosubstances, and the system should be a valuable method for the evaluation of the antioxidant ability. Springer-Verlag Wien, 2015 Nakajima Akira Department of Biotechnology, Frontier Science Research Center, University of Miyazaki, Kiyotake, 889-1692, Miyazaki, Japan aut Yamaguchi Tomoko Venture Laboratory, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, 606-8585, Kyoto, Japan aut Yamashita Tomoyuki Department of Biomolecular Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, 606-8585, Kyoto, Japan aut Kawai Kiyoshi Department of Biomolecular Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, 606-8585, Kyoto, Japan aut Miyake Yusuke Department of Biomolecular Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, 606-8585, Kyoto, Japan aut Kanaori Kenji Department of Biomolecular Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, 606-8585, Kyoto, Japan aut Tajima Kunihiko Department of Biomolecular Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, 606-8585, Kyoto, Japan aut Applied Magnetic Resonance Springer Vienna 46/9(2015-09-01), 1013-1022 0937-9347 46:9<1013 2015 46 723 https://doi.org/10.1007/s00723-015-0664-5 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00723-015-0664-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Nakajima Akira Department of Biotechnology, Frontier Science Research Center, University of Miyazaki, Kiyotake, 889-1692, Miyazaki, Japan aut NATIONALLICENCE 700 1- Yamaguchi Tomoko Venture Laboratory, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, 606-8585, Kyoto, Japan aut NATIONALLICENCE 700 1- Yamashita Tomoyuki Department of Biomolecular Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, 606-8585, Kyoto, Japan aut NATIONALLICENCE 700 1- Kawai Kiyoshi Department of Biomolecular Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, 606-8585, Kyoto, Japan aut NATIONALLICENCE 700 1- Miyake Yusuke Department of Biomolecular Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, 606-8585, Kyoto, Japan aut NATIONALLICENCE 700 1- Kanaori Kenji Department of Biomolecular Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, 606-8585, Kyoto, Japan aut NATIONALLICENCE 700 1- Tajima Kunihiko Department of Biomolecular Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, 606-8585, Kyoto, Japan aut NATIONALLICENCE 773 0- Applied Magnetic Resonance Springer Vienna 46/9(2015-09-01), 1013-1022 0937-9347 46:9<1013 2015 46 723