Molecular structure and reactivity of antituberculosis drug molecules isoniazid, pyrazinamide, and 2-methylheptylisonicotinate: a density functional approach

Density functional theory calculations have been performed to determine structure and reactivity of two of the most commonly used antitubercular drug molecules, isoniazid and pyrazinamide. Having found good agreement with the available experimental data for these two compounds, we extended DFT calculation to predict the properties of 2-methylheptylisonicotinate which is a novel natural analogue of isoniazid. The chemical reactivity of these compounds was compared using density functional-based descriptors such as global softness, global electrophilicity, Fukui function, and philicity. The experimental better reactivity of 2-methylheptylisonicotinate with respect to the well-known antituberculosis drug molecule, isoniazid has been successfully established.