QSAR study of antituberculosis activity of oxadiazole derivatives using DFT calculations

Mycobacterium tuberculosis (Mtb) is the causative agent of infectious diseases worldwide. Oxadiazole derivatives have many biological activities and can be a good alternative to antimicrobial drugs. In this study, the quantitative structure-activity relationship (QSAR) of fifty-one novel oxadiazoles derivatives has been studied using the density functional theory (DFT) and statistical methods. Becke's three-parameter hybrid method and the Lee-Yang-Parr B3LYP functional employing 6-31++G (d) basis set are used to calculated quantum chemical descriptors using Gaussian09 software. The other descriptors including Lipinski, physicochemistry, topological, etc. were calculated using Chembio3d software. Statistically, the best correlation between the independent variables and the PMIC as the dependent variable was a 6-variable equation for which the correlation coefficient were as follows R² = 0.86 and R = 0.93. Also, the values of MAE = 0.003 and Q²_CV = 0.9 confirm the acceptability of the obtained model. The obtained equation shows that NRB, energy gap (ΔE), Henry's law constant, O-C, and C-N bonds length, and the Free Gibbs energy have the highest correlation with the anti-Tb activity.