Experimental and theoretical study on antioxidant activity of the four anthocyanins

This study aimed to investigate the antioxidant properties of four anthocyanins from purple potato. The antioxidant activities were evaluated using the DPPH radical scavenging ability assay and the ability to inhibit lipid peroxidation. All of the tested anthocyanins showed good antioxidant activities. Also, two main antioxidative mechanisms, including H atom transfer (HAT) and single electron transfer (CT), were examined at the B3LYP/6-31G(d) level of theory. The results showed 4'-OH possessed lower bond dissociation enthalpy (BDE) values compared with that of other OH groups. All anthocyanins were demonstrated that can be used as good candidates to donate an H atom to give rise to originate stable radical species. Among all investigated molecules, resveratrol exhibited the lowest ionization potential (IP). And four anthocyanins displayed significantly various IP values after substituted with glycoside ligand. Analysis of necessary pharmacophores by the molecular simplification method suggested that the synergetic effect of simplified models was responsible for the antioxidative activity. (C) 2019 Published by Elsevier B.V.