Repair Activity of trans-Resveratrol toward 2′-Deoxyguanosine Radicals

Abstract

In the present study, the repair activity of trans-resveratrol toward 2'-deoxyguanosine (dGuo) radicals in polar and nonpolar solvents was studied using density functional theory. The hydrogen transfer/proton coupled electron transfer and single electron transfer (SET) mechanisms between trans-resveratrol and dGuo-radicals were considered. Taking into consideration the molar fraction of neutral trans-resveratrol (ROH) and anionic trans-resveratrol (RO), the overall rate constants for repairing dGuo-radicals by trans-resveratrol are 9.94 × 10 and 2.01 × 10 dm mol s in polar and nonpolar solvents, respectively, and the overall rate constant of repairing cation radical (dGuo) by trans-resveratrol via an SET mechanism is 7.17 × 10 dm mol s. The repair activity of RO toward dGuo-radicals is better than that of ROH, but the repair activity of ROH toward dGuo is better than that of RO. Unfortunately, neither ROH nor RO can repair the 2'-deoxyribose radicals of dGuo. It can therefore be concluded that trans-resveratrol is an effective antioxidant for repairing base radicals of dGuo and dGuo. The study can help us understand the repair activity of trans-resveratrol toward dGuo radicals.

Repair of Oxidizing Hydroxyl Adduct Radicals of DNA Bases by Hydroxyl‐trans‐Stilbenes via Single Electron Transfer

“…Resveratrol and other hydroxylstilbenes with 4′‐OH group exhibited lower toxicity, and their radicals have semiquinone structures and are very stable. In a recent work from our group, we studied the repair activity of trans ‐resveratrol toward 2′‐deoxyguanosine radicals and found that trans ‐resveratrol could repair base radicals rather than 2′‐deoxyribose radicals and the repair activity of trans ‐resveratrol anion toward 2′‐deoxyguanosine radicals is better than that of neutral trans ‐resveratrol. However, detail kinetic data for the reactions involved in repairing oxidizing DNA base‐OH‐adduct radicals by hydroxyl‐ trans ‐stilbenes have not been reported until now.…”

“…Gibbs free energy G was calculated as following equation: G = E HF + G 0 , where E HF represents the total calculated electronic energy at the M06‐2X / ma‐TZVP // 6–311G (d, p) level and G 0 is the thermal correction to Gibbs free energy at the M06‐2X / 6–311G (d, p) level. The method used for calculating Gibbs free energy in this study has been applied in the literature ,,…”

“…The vertical ionization potential (VIP) and vertical electron affinity (VEA) are calculated as the following equations, (6) and (7), respectively: …”