Computational Investigation on the ∙OOH Scavenging Sites of Gnetin C

Melinjo seed extract contains melinjo resveratrol compounds that has antioxidant activity. The radical-scavenging sites required for the antioxidant activity, however, is yet to be located. We report a computational study that aims to locate scavenging sites of the simplest resveratrol dimer, gnetin C. We consider the reaction of gnetin C and hydroperoxyl radical energetically with the basis of density-functional calculations, to be compared with the reaction of the resveratrol monomer, trans-resveratrol, and hydroperoxyl radical. The results show that OH group at the para position is the most reactive scavenging site for both molecules. Besides the OH group, gnetin C also provides two CH groups in the furan ring that are favorable as scavenging sites. Therefore, furan ring plays an important role in the scavenging activity, which is contrary to the experimental speculation that propose resorcinol ring. Our study shows the prospect of density-functional calculation for studying the radical-scavenging reaction.