Redox reactions of the urate radical/urate couple with the superoxide radical anion, the tryptophan neutral radical and selected flavonoids in neutral aqueous solutions
2001; Taylor & Francis; Volume: 35; Issue: 2 Linguagem: Inglês
10.1080/10715760100300671
ISSN1071-5762
AutoresRené Santús, L. K. Patterson, Paulo Filipe, Patrice Morlière, Gordon L. Hug, Afonso Fernandes, Jean‐Claude Mazière,
Tópico(s)Genomics, phytochemicals, and oxidative stress
ResumoAbstractThe kinetics of several processes involving the potential antioxidant role of urate in physiological systems have been investigated by pulse radiolysis. While the monoanionic urate radical, ·UH-, can be produced directly by oxidation with ·Br-2 or ·OH, it can also be generated by oxidation with the neutral tryptophan radical, ·Trp, with a rate constant of 2 × 107 M-1s-1. This radical, ·UH-, reacts with ·O-2 with a rate constant of 8 × 108 M-1s-1. Also, ·UH- is reduced by flavonoids, quercetin and rutin in CTAB micelles at rate constants of 6 × 106 M-1s-1 and 1 × 106 M-1s-1, respectively. These results can be of value by providing reference data useful in further investigation of the antioxidant character of urate in more complex biological systems.Keywords: Antioxidantselectron transferflavonidsmicellespulse radiolysistryptophan
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