Mechanistic processes of resveratrol in inhibiting the oxidative damage of guanine, as evidenced by UHPLC-MS2

Agarose gel electrophoresis assay demonstrates that DNA was damaged by 1O2 under 5 min UVA irradiation and 5 mM Resveratrol dissolved in MeOH could relieve the oxidation stress. Additionally, UHPLC-QTOF-MS2 was performed to find four Guanine oxidation products at m/z 140.0334 [M-H]−(1), DGh, 8-oxoG and Sp, and two conjugates at m/z 377.1104 [M-H]− and 391.0907 [M-H]−. Thus, we proposed the mechanism that phenol ring of Resveratrol link with the free amino groups (-NH) of Guanine at the beginning of 1O2 attacking to form m/z 377.1104 [M-H]−, however, as 1O2 attacking continuously, Resveratrol can efficiently react with 1O2 first to achieve the protection of Guanine.157