2013年11月
Kinetic study of aroxyl radical scavenging and α-tocopheroxyl regeneration rates of pyrroloquinolinequinol (PQQH2, a reduced form of pyrroloquinolinequinone) in dimethyl sulfoxide solution: Finding of Synergistic Effect on the Reaction Rate due to the Coexistence of α-Tocopherol and PQQH2
American Chemical Society, J. Agric. Food Chem.
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- 巻
- 61
- 号
- 46
- 開始ページ
- 11048
- 終了ページ
- 11060
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1021/jf4040496
- 出版者・発行元
- AMER CHEMICAL SOC
Measurements of aroxyl radical (ArO•)-scavenging rate constants (ksAOH) of antioxidants (AOHs: pyrroloquinolinequinol (PQQH 2), α-tocopherol (α-TocH), ubiquinol-10 (UQ 10H2), epicatechin, epigallocatechin, epigallocatechin gallate, and caffeic acid) were performed in dimethyl sulfoxide (DMSO) solution, using stopped-flow spectrophotometry. The ksAOH values were measured not only for each AOH but also for the mixtures of two AOHs ((i) α-TocH and PQQH2 and (ii) α-TocH and UQ10H2). A notable synergistic effect that the ksAOH values increase 1.72, 2.42, and 2.50 times for α-TocH, PQQH2, and UQ10H2, respectively, was observed for the solutions including two kinds of AOHs. Measurements of the regeneration rates of α-tocopheroxyl radical (α-Toc•) to α-TocH by PQQH2 and UQ 10H2 were performed in DMSO, using double-mixing stopped-flow spectrophotometry. Second-order rate constants (kr) obtained for PQQH2 and UQ10H2 were 1.08 × 105 and 3.57 × 104 M-1 s-1, respectively, indicating that the kr value of PQQH2 is 3.0 times larger than that of UQ10H2. It has been clarified that PQQH2 and UQ10H2 having two HO groups within a molecule may rapidly regenerate two molecules of α-Toc • to α-TocH. The result indicates that the prooxidant effect of α-Toc• is suppressed by the coexistence of PQQH2 or UQ10H2. © 2013 American Chemical Society.
- リンク情報
- ID情報
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- DOI : 10.1021/jf4040496
- ISSN : 0021-8561
- PubMed ID : 24175624
- SCOPUS ID : 84888347768