Scavenging rate constants of hydrophilic antioxidants against multiple reactive oxygen species
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- Sueishi Yoshimi
- Department of Chemistry, Faculty of Science, Okayama University
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- Hori Masashi
- Department of Chemistry, Faculty of Science, Okayama University
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- Ishikawa Misa
- Department of Chemistry, Faculty of Science, Okayama University
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- Matsu-ura Keiko
- Department of Chemistry, Faculty of Science, Okayama University
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- Kamogawa Erisa
- Department of Chemistry, Faculty of Science, Okayama University
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- Honda Yusaku
- Department of Chemistry, Faculty of Science, Okayama University
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- Kita Masakazu
- Graduate School of Education, Okayama University
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- Ohara Keishi
- Graduate School of Science and Engineering, Ehime University
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Description
Scavenging rate constants of eight hydrophilic antioxidants, including caffeic acid, chlorogenic acid, genistein, glutathione, N-acetylcysteine, rutin, trolox, and uric acid against multiple ROS, namely superoxide anion, hydroxyl radical, singlet oxygen, and alkoxyl radical were determined with the electron spin resonance method. Direct flash photolysis measurement of the second-order rate constant in the reaction of alkoxyl radical plus the spin trap 5,5-dimethyl-pyrroline N-oxide made it possible to evaluate scavenging rate constants in antioxidants. The magnitudes of scavenging rate constants were notably dependent on the character of each ROS and the overall rate constants were highest in hydroxyl radical scavenging and the lowest in superoxide anion. The highest scavenging rate constant against superoxide anion was obtained by chlorogenic acid (2.9 × 105 M−1 s−1) and the lowest was by N-acetylcysteine (5.0 × 102 M−1 s−1). For singlet oxygen, the highest was by glutathione (9.4 × 108 M−1 s−1) and the lowest was by uric acid (2.3 × 106 M−1 s−1). All other numbers are listed and illustrated. Redox potential measurements of the antioxidants indicated that the antioxidants are likely to react with superoxide anion and singlet oxygen through electron transfer processes.
Journal
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- Journal of Clinical Biochemistry and Nutrition
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Journal of Clinical Biochemistry and Nutrition 54 (2), 67-74, 2014
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