A QSAR Study of 2-carboxamide-1,4-di-N-oxide quinoxaline Derivatives

A set of density functional theory (DFT) calculations were performed on 2-carboxamide 1,4- di-N-oxide quinoxaline (2CdNOQ) derivatives. The optimized structure of these compounds in three forms was obtained. Some electronic parameters including dipole moment (μ), ionization potential (I), electron affinity (A), LUMO energy (εLUMO), HOMO energy (εHOMO), electronegativity (χ), hardness (η), electrophilicity (ω), and differences between HOMO and LUMO energies (εLUMO–εHOMO), for the most stable conformer, were calculated. Quantitative structure–activity relationship (QSAR) models of the biological activity (IC50) of these compounds were established using the calculated quantum mechanical descriptors. Also, the first, second, total, and mean N-O bond dissociation enthalpies were also obtained theoretically and were correlated to reported experimental inhibition.