Antioxidant Activity, Molecular Docking and Quantum Studies of New <i>Bis</i> ‐Schiff Bases Based on Benzyl Phenyl Ketone Moiety
Rashid Ahmad, Aftab Alam, Momin Khan, Tahseen Ali, Ahmed A. Elhenawy, Manzoor Ahmad
Abstract
Abstract In the current research work novel bis ‐Schiff base products of benzyl phenyl ketone nucleus were synthesized via two step reactions in excellent yields. Using FTIR, EI‐MS and 1 H‐NMR spectroscopic procedures, the structures of synthesized derivatives were confirmed and finally evaluated them for DPPH free radical scavenging activity. In the synthetic series, compounds 2 c (IC 50 =26.11±0.12 μ M), 2 b (IC 50 =30.33±0.22 μ M), 2 d (IC 50 =38.19±0.65 μ M), and 2 a (IC 50 =40.12±0.42 μ M) exhibited excellent activity better than standard drug ascorbic acid (IC 50 =44.01±1.41 μ M) while the rest of derivatives revealed good to moderate activity. Frontier molecular orbitals, like HOMO and LUMO, which show charge transfer from molecule to biological transfer, and MEP maps, which show the chemically reactive zone suited for drug action, are calculated using DFT study. Non bonding orbitals (NBO), the electron localization function (ELF) and atoms in molecule (AIM) charges is also calculated. Strong hydrogen bonding interactions with crucial amino acid residues of the peroxidase structure are revealed by the molecular docking analysis of the drug with DPPH for efficient inhibition.