Mechanism of Resveratrol Dimers Isolated from Grape Inhibiting 1O2 Induced DNA Damage by UHPLC-QTOF-MS2 and UHPLC-QQQ-MS2 Analyses

Resveratrol dimers have been extensively reported on due to their antioxidative activity. Previous studies revealed that resveratrol dimer has been shown to selectively quench singlet oxygen (1O2), and could protect DNA from oxidative damage. The mechanism of resveratrol dimers protecting DNA against oxidative damage is still not clear. Therefore, in this project, the reactants and products of resveratrol dimers protecting guanine from oxidative damage were qualitatively monitored and quantitatively analyzed by UHPLC-QTOF-MS2and UHPLC-QQQ-MS2. Results showed that when guanine and resveratrol dimers were attacked by1O2, mostly resveratrol dimers were oxidized, which protected guanine from oxidation. Resveratrol dimers’ oxidation products were identified and quantified atm/z467.1134 [M-H]−and 467.1118 [M-H]−, respectively. The resorcinol of resveratrol dimers reacted with singlet oxygen to produce p-benzoquinone, protecting guanine from1O2damage. Therefore, it is hereby reported for the first time that the resorcinol ring is the characteristic structure in stilbenes inhibiting1O2induced-DNA damage, which provides a theoretical basis for preventing and treating DNA damage-mediated diseases.Keywords:resveratrol dimers;antioxidative activity;singlet oxygen quenching;DNA damage