Redox reactions of the urate radical/urate couple with the superoxide radical anion, the tryptophan neutral radical and selected flavonoids in neutral aqueous solutions

The 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...

Full description

Saved in:
Bibliographic Details
Published in:Free radical research 2001-01, Vol.35 (2), p.129-136
Main Authors: Santus, René, Patterson, Larry K., Filipe, Paulo, Morlière, Patrice, Hug, Gordon L., Fernandes, Afonso, Mazière, Jean-Claude
Format: Article
Language:English
Subjects:
Animals
Antioxidants
Catechin - metabolism
Cattle
electron transfer
flavonids
Flavonoids - metabolism
Kinetics
Micelles
Oxidation-Reduction
Pulse Radiolysis
Quercetin - metabolism
Rutin - metabolism
Solutions - metabolism
Spectrophotometry, Ultraviolet
Superoxides - chemistry
Superoxides - metabolism
tryptophan
Tryptophan - chemistry
Tryptophan - metabolism
Uric Acid - chemistry
Uric Acid - metabolism
Water - metabolism
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The 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.
ISSN:1071-5762
1029-2470
DOI:10.1080/10715760100300671