Abstract: Based on the structure of resveratrol (A),six resveratrol analogues (B-G) were designed.Then the relationship between the structure and antioxidant activity of resveratrol and its derivatives were studied in the gas phase and solvents using quantum chemical calculations based on the density functional theory (DFT).The three main working mechanisms,H-atom transfer (HAT),single electron transfer-proton transfer (SET-PT) and sequential proton loss electron transfer (SPLET) were investigated.The result showed that HAT would be the most favorable mechanism for explaining the radical scavenging activity of four compounds in the gas phase,whereas the SPLET mechanism would be the thermodynamically favorable pathway in polar solvents.The calculations suggested that,SET-PT was not the most preferred mechanism in all environments studied.

Key words: resveratrol, antioxidant mechanism, density functional theory, ionization potential, proton affinity