Density functional theory calculations of spectral, NLO, reactivity, NBO properties and docking study of Vincosamide-N-Oxide active against lung cancer cell lines H1299

Abstract

The present paper reports the density functional theory calculations of IR, NMR and UV–Visible, nonlinear optical (NLO) properties, highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energy band gap as measure of reactivity, molecular electrostatic potential surface (MESP), thermodynamic parameters and natural bond orbital (NBO) properties of the title molecule as well as its possible protein–ligand interactions using molecular docking approach. Theoretical NMR chemical shifts (1H and 13C) as well as the characteristics regions in IR active vibrations are in fair agreement with their experimental counterparts. UV–Visible absorption peak resulting from electronic transitions HOMO-5 → LUMO, HOMO-4 → LUMO observed at 324.27 nm is also in good agreement with its experimental value. The first order hyper polarizability of this molecule has been calculated to be 3182.124 × 10–33 esu which is 9.26 times to that of Urea indicating its suitability for nonlinear optical applications. The HOMO–LUMO energy band gap has been found to be reasonably small ≈ − 0.14596 a.u and MESP surface to be a chemically reactive site suited for drug activity. It is observed that the C11-atom of ring is more prone to the electrophilic attack. NBO analysis reveals that donor (O23) π → π *(C18-N22) acceptor interaction corresponds to the highest second order perturbation energy E(2) = 29.12 kcal/mole associated with electron delocalization. This biomolecule binds with 1GCN, 1HSG, 1X2J, 2NMO, 3I40 and 5C5S protein receptors showing that this molecule possesses multifunctional biological activity. Nonlinear optical and multifunctional biological activity reported in our study may be exploited for the novel applications of the heading molecule.