A comparative investigation on the scavenging of 2,2-diphenyl-1-picrylhydrazyl radical by the natural antioxidants (+) catechin and (-) epicatechin

•2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) scavenging capacity of natural antioxidants catechin (CT) and epicatechin (ECT) was investigated experimentally.•Theoretical outcome predicted that interaction between CT/ECT and DPPH• could take place spontaneously with an exothermic process.•The observed red shift in the normal mode of vibration at the active site of CT/ECT mainly ascribed to the hydrogen bond (O-O-H…N) interaction with DPPH•.•Topological and AIM analysis confirms the non-covalent type interaction.