Density functional study of the antioxidant activity of some recently synthesized resveratrol analogues.

In this paper we have investigated the two main working mechanisms (H atom and single-electron transfer) of five new potential antioxidant analogues of cis-resveratrol. The O-H bond dissociation energy (BDE) and ionization potential (IP) key parameters were computed in methanol. Results obtained indicate that all the examined compounds are more efficient antioxidants than the molecule from which they derive, mainly due to their higher degree of conjugation and the capability to delocalize the π-electrons which contribute to the stabilization of the radical species. The enhancement of these stabilizing effects is in part a result of the introduction of a single bond between the C2' and C6 carbon atoms of cis-resveratrol that generates a new central aromatic ring. However, the number of hydroxyl groups and in particular the presence of the catechol moiety remains the most significant features in determining the order of radical scavenging potentiality. Spectroscopic UV-Vis characterization is also reported and discussed.