Investigation of reactive and spectroscopic properties of oxobutanoic acid derivative: Combined spectroscopic, DFT, MD and docking study

Abstract

The optimized geometry and wavenumbers of 4-[(4-acetylphenyl)amino]-2-methylidene-4-oxobutanoic acid (APAMOB) have been calculated by density functional theory (DFT) using Becke's three-parameters hybrid functional (B3LYP) with 6–311++G(d) (5D, 7F) basis set. The theoretically predicted vibrational wavenumbers were compared with the observed FT-IR and FT-Raman spectra. The NH stretching wavenumber is red shifted in the IR spectrum from the computed wavenumber, which indicates the weakening of the NH bond. The ring breathing mode of the para substituted phenyl ring is assigned at 836 cm−1 experimentally and at 835 cm−1 theoretically. Molecular electrostatic potential map has also been plotted for predicting the reactive sites in the molecule. Using natural bond orbitals analysis hyperconjugative interactions and second order stabilization energies are calculated. Nonlinear optical properties of the molecule are predicted. In order to determine molecule sites that could be sensitive towards electrophilic attacks we have calculated ALIE values and mapped them to electron density surface. In the same way we have also visualized Fukui functions, which helped us to further gain an insight into the local reactivity properties of title molecule. Bond dissociation energies (BDE) have been calculated in order to determine if autoxidation mechanism is possible, while the potential influence of hydrolysis was investigated to calculations of radial distribution functions (RDF) obtained after molecular dynamics (MD) simulations. Molecular docking study suggests that the title compound shows the inhibitory activity against 2-deoxy-d-gluconate 3-dehydrogenase.