In-Silico Molecular Docking Study of Coumarin Derivatives in order to Investigate the Inhibitory Effects of Human Monoamine Oxidase Enzyme and DFT Studies

In the present study, DFT calculations of four coumarin derivatives and also their molecular docking with “human monoamine oxidase enzyme” (HMAO) were performed in order to study the inhibitory effect of these compounds. The optimized molecular geometries and vibrational frequencies were calculated at the B3LYP/6-31+G(d) level of theory without any imaginary frequency. The total energy, dipole moment and energies of the frontier molecular orbitals were calculated for all the compounds. All quantum calculations were performed using the Gaussian 03 software. The molecular docking of coumarin derivatives and phenelzine with HMAO enzyme were calculated and inhibitory effect of coumarins were compared with phenelzine. Also the binding free energy, amino acid residue and hydrogen bond interactions between all the compounds and HMAO enzyme were calculated. The binding energies for coumarins and Phenelzine are in the range of 7.04 – -6.15 Kcal/mol. The binding energy potency follows the order of: 4>2>3>1> Phenelzine. The binding energy of all the compounds with HMAO enzyme was stronger than Phenelzine.