Spectroscopic, DFT, molecular dynamics and molecular docking study of 1-butyl-2-(4-hydroxyphenyl)-4,5-dimethyl-imidazole 3-oxide

Abstract

FT-IR and FT-Raman spectrum of 1-butyl-2-(4-hydroxyphenyl)-4,5-dimethyl-imidazole 3-oxide were recorded and theoretical study has been made using Gaussian09 software package. DFT/B3LYP calculations have been done using 6-311++G (d, p) (5D, 7F) basis sets to investigate the vibrational frequencies and geometrical parameters. The assignments of the normal modes are done by potential energy distribution (PED) calculations. First and second hyperpolarizabilities are calculated in order to find its role in non-linear optics. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. Molecular Electrostatic Potential was calculated by the DFT method and predicts the most reactive part in the molecule. The calculated NMR values are in good agreement with experimental data. Reactive sites of the title molecule have been determined by calculations of average local ionization surfaces and Fukui functions. Analyzing electron density between atoms, intra-molecular non-covalent interactions have been determined. Possible locations prone to autoxidation and locations where degradation could start have been determined by calculation of bond dissociation energies for all single acyclic bonds. Atoms with pronounced interactions with water molecules have been located by calculations of radial distribution functions, obtained after molecular dynamics simulations. The docked title compound forms a stable complex with CDK inhibitor and gives a binding affinity value of −6.3 kcal/mol and the results suggest that the compound might exhibit inhibitory activity against CDK inhibitor.