Density functional theory investigations of radical scavenging activity of 3′-Methyl-quercetin

The possible eight rotamers of 3′-Methyl-quercetin have been optimized by using density functional theory (DFT) at B3LYP/6-31G∗ level of theory. The molecular structure and molecular properties of the most stable rotamers have been investigated at the same level of theory. We have computed the descriptors; electronegativity (χ), hardness (η), electrophilicity (ω), softness (S) and electrophilicity index (ωi) by DFT approach. We have shed light on the structure-property relationship. The absorption spectrum has been computed by time dependent density functional theory (TD-DFT) at TD-B3LYP/6-31G∗ level of theory. Radical scavenging activity has been explained on the basis of bond dissociation enthalpy (BDE) and the adiabatic ionization potential (IP). Two mechanisms have been explained for the radical scavenging processes, i.e., hydrogen atom transfer and one-electron transfer.