Computational Study of Novel 2,3-Bis[(1-methyl-1H-imidazole-2-yl)sulfanyl]quinoxaline: Structural Aspects, Spectroscopic Investigation, HOMO-LUMO, MESP, NLO, ADMET Predictions and Molecular Docking Studies as Potential Biotin Carboxylase and Antibiotics Resistant Aminoglycoside Phosphotransferase APH(2")IVA Enzyme Inhibitor

Abstract

In this paper, a complete quantum chemical calculation has been done to describe the relevant structural aspects of novel 2,3-bis[(1-methyl-1H-imidazole-2-yl)sulfanyl]quinoxaline with combination of DFT/B3LYP method 6-311++G(d,p) basis set in gas phase and in solvent phase. The molecular structure was examined by using IR, 1H & 13C NMR and UV-visible techniques and solvent effect on spectroscopic properties are also discussed. The vibrational assignments are analyzed by PED using Gauss View 5.0 and VEDA 4.0 program. The 1H NMR and 13C NMR chemical shifts are calculated using the gauge-independent atomic orbital method (GIAO method) in gas phase and in solvents (water, DMSO and chloroform). The UV spectrum is calculated by using TD-DFT/6-311++G(d,p) method in gas phase and in solvent (water, DMSO and chloroform) using IEF-PCM model. With the help of theoretical calculations chemical activities, electrophilic/nucleophilic nature and sites in the molecule, molecular and chemical properties that cannot be obtained by experimental way are obtained. Accordingly, molecular electrostatic potential (MESP), hardness (η)/softness (S) parameters, net charges analyses are investigated to gain electrophilic and nucleophilic nature. Also the sites in molecule and Fukui function analysis are discussed. The dipole moment (μ), polarizability (αtot), anisotropic polarizability (Δα) and first-order hyperpolarizability (βtot) of the title compound are reported and results shows that the material is capable to generate non-linear effect (NLO). The in silico study of all th e biological and ADMET properties of title molecule are also discussed and compared with reference drug ciprofloxacin antibiotics. The title molecule and reference drug ciprofloxacin docked with biotin carboxylase enzyme (PDB ID: 2V59) of E. coli and aminoglycoside phosphotransferase APH(2")IVA (PDB ID: 4DFU) of Enterococcus casseliflavus receptor with the help of Molegro molecular viewer 2.5 program and binding affinity (ΔG) were determined by ParDock server.