title: Radical-induced oxidation of trans-resveratrol.
abstract: trans-Resveratrol (RVT) (3,5,4'-trihydroxystilbene), a polyphenolic constituent of red wine, is thought to be beneficial in reducing the incidence of cardiovascular diseases, partly via its antioxidant properties. However, the mechanism of action by which trans-resveratrol displays its antioxidant effect has not been totally unravelled. This study aimed at establishing a comprehensive scheme of the reaction mechanisms of the direct scavenging of HO(*) and O(2)(*-) radicals generated by water gamma radiolysis. Aerated aqueous solutions of trans-RVT (from 10 to 100μmolL(-1)) were irradiated with increasing radiation doses (from 25 to 400Gy) and further analyzed by UV-visible absorption spectrophotometry for detection of trans-RVT oxidation products. Separation and quantification of RVT and its four oxidation products previously identified by mass spectrometry, i.e., piceatannol (PCT), 3,5-dihydroxybenzoic acid (3,5-DHBA), 3,5-dihydroxybenzaldehyde (3,5-DHB) and para-hydroxybenzaldehyde (PHB), were performed by HPLC/UV-visible spectrophotometry. Determination of the radiolytic yields of trans-RVT consumption and oxidation product formation has allowed us to establish balance between trans-RVT disappearance and the sum of oxidation products formation. Under our conditions, O(2)(-) radicals seemed to poorly initiate oxidation of trans-RVT, whereas the latter, whatever its initial concentration, quantitatively reacted with HO() radicals, via a dismutation mechanism. Two reaction pathways involving HO()-induced trans-RVT primary radicals have been proposed to explain the formation of the oxidation end-products of trans-RVT.
authors: EA 4466, Département de Biologie Expérimentale, Métabolique et Clinique, Faculté des Sciences Pharmaceutiques et Biologiques, Université Paris Descartes, Sorbonne Paris Cité, 4 avenue de l'Observatoire, 75006 Paris, France.
authors: Laurent
authors: L
authors: Camont
authors: Fabrice
authors: F
authors: Collin
authors: Martine
authors: M
authors: Couturier
authors: Patrice
authors: P
authors: Thérond
authors: Daniel
authors: D
authors: Jore
authors: Monique
authors: M
authors: Gardès-Albert
authors: Dominique
authors: D
authors: Bonnefont-Rousselot
mesh_terms: D005720:Gamma Rays; D017665:Hydroxyl Radical / Q000737:chemistry*; D010084:Oxidation-Reduction; D017382:Reactive Oxygen Species / Q000737:chemistry; D000077185:Resveratrol; D013267:Stilbenes / Q000737:chemistry*
chemical_list: D017382:Reactive Oxygen Species; D013267:Stilbenes; D017665:Hydroxyl Radical; D000077185:Resveratrol