Quantum chemical investigation of the antiradical property of avenanthramides, oat phenolics

Avenanthramides (AVs) are polyphenolic components found in oats. The present work is devoted to the exploration of structure-based radical scavenging activity of nine AVs; 2p, 2f, 2c, 1p, 1c, 1f, 1s, 2s, and 3f, using M06-2X functional level of density functional theory with basis set 6-31+G(d, p) both in gas and ethanol medium. The act of compounds towards the electron transfer mechanism was analyzed with the help of a Donor-acceptor map (DAM) and classified as antioxidants and anti-reductants. The main mechanism of radical action, HAT, SET-PT, and SPLET were examined and found to be the preference of HAT and SPLET respectively in the gas phase and ethanol medium. The computed quantum mechanical atom in molecule (QTAIM) parameters; the intramolecular H-bonding, Noncovalent interactions, aromaticity also acted as pillars to supports the activity of compounds. The activity was found to be increasing with the stabilizing group ortho to the reactive phenolic OH group.