Liquid chromatographic/electrospray ionization mass spectrometric identification of the oxidation end-products oftrans-resveratrol in aqueous solutions

traits-Resveratrol (3,5,4'-trihydroxystilbene) is a natural polyphenolic compound that exhibits antioxidant properties. Our study aimed at studying the HO center dot-induced oxidation of resveratrol (100 mu mol.L-1) in aerated aqueous solutions. Gamma radiolysis of water was used to generate HO center dot/O-2(-) free radicals (I = 10 Gy.min(-1), dose = 400 Gy). Oxidation products were identified by direct infusion mass spectrometry and high-performance liquid chromatography/mass spectrometry. For each product, structural elucidation was based on simple mass spectra, fragmentation spectra and deuterium/hydrogen exchange spectra; the comparison with mass spectra of synthetic products provided valuable information allowing the complete identification of the oxidation products. Four products resulting from the direct attack of HO center dot radicals towards resveratrol were identified respectively as piceatannol (trans-3,5,3',4'-tetrahydroxystilbene), 3,5-dihydroxybenzoic acid, 3,5-dihydroxybenzaldehyde and 4-hydroxybenzaldehyde. Copyright (C) 2010 John Wiley & Sons, Ltd.