Abstract: In this paper,resveratrol and its derivatives (a-h) were optimized using the density functional theory (DFT) at B3LYP/6-311G(d,p) level of theory and the single point were obtained at B3LYP/6-311++G(2d,2p) level on the basis of optimized configuration.The three main working mechanisms,H-atom transfer (HAT),single electron transfer–proton transfer (SET–PT) and sequential proton loss electron transfer (SPLET) have been investigated through parameters O–H bond dissociation enthalpy (BDE),ionization potential (IP),proton dissociation enthalpy (PDE),proton affinity (PA) ,electron transfer enthalpy (ETE),and so on.The results show that the OH on different positions has different activity.The C4’-OH of B ring has the strongest activity.For different antioxidant mechanisms the materials show different antioxidant activities.In the HAT mechanism the order of antioxidant efficiencies is Res>e>a>b≈d≈g>f≈h>c,whereas in the SET-PT mechanism the order is Res>e>h>a>f>d>b>g>c.The calculations also suggest that in the SPLET mechanism the order is d>Res>e>f>h>a>b>g>c.

Key words: antioxidation, density functional theory (DFT), bond dissociation enthalpy, ionization potential