The influence of various phenolic compounds on scavenging activity assessed by an enzymatic method
✍ Scribed by de Gaulejac, Nathalie Saint-Cricq; Vivas, Nicolas; de Freitas, Victor; Bourgeois, Guy
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 204 KB
- Volume
- 79
- Category
- Article
- ISSN
- 0022-5142
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✦ Synopsis
The effect of pure monomeric and dimeric procyanidins on superoxide anion radicals (O 2 °À) was studied with an enzymatic method and their IC 50 was determined. A comparative study of the results suggested that the antiradical potential of these phenolic compounds closely depends on their stereochemical structure. Modi®cation of the chiral carbon, C 3 involved in the oxidation mechanism induces differences in the scavenging action of ()-catechin (2R:3S) or (À)-epicatechin (2R:3R). The stereochemical conformation of the inter¯avan linkage (axial or pseudo) according to the chemical nature of dimeric procyanidin units also in¯uences the radical oxidation mechanism. The nature of the inter¯avan linkage between the two units in dimeric procyanidins (C 4 ±C 8 or C 4 ±C 6 linkage) is an important factor responsible for effectiveness of the behaviour polyphenols towards O 2 °À. The extraction of oligomeric procyanidins in grape seeds enabled us to study the effect of polymerisation and galloylation on their scavenging activities. The results clearly showed that the molecular scavenging mechanism of these molecules is closely connected with their spatial conformation.