Isoniazid-Isatin Hydrazone Derivatives: Synthesis, Antitubercular Activity and Molecular Docking Studies

Abstract

This study examined the synthesis of isoniazid-isatin hydrazone derivatives 5-7, followed by an investigation on the in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv, and molecular docking. A yield of 81 - 92 % of these compounds was achieved, with structural characterization by spectroscopic methods (FTIR, NMR, HRMS). The in vitro antitubercular activity was evaluated against M. tuberculosis H37Rv, and the highest effect was observed in compound 7, with a minimum inhibitory concentration (MIC) of 0.017 mM, lower than rifampicin (MIC 0.048 mM), which served as the positive control. In addition, the molecular docking of 5-7 was performed to visualize the interaction of isoniazid-isatin hydrazone derivatives with the active site of InhA receptor, which was in agreement with the experimental data. The hydrogen bonding with Ser94 and pi-pi interaction with Phe41 and/or Phe97 on the InhA active site was pivotal for the antitubercular activity. HIGHLIGHTS Tuberculosis caused by Mycobacterium tuberculosis is one of the top ten leading causes of death globally The first and second lines of antituberculosis drugs are the prevalent treatment for this disease, but they show several drawbacks and are exacerbated by the occurrence of drug resistance The isoniazid-isatin hydrazone derivatives were designed through molecular hybridization and synthesized effectively and exhibited moderate to high activity against tuberculosis H37Rv Molecular docking study demonstrated that the hydrogen bonding with Ser94 and the pi-pi interaction with Phe41 and/or Phe97 are important for antitubercular activity GRAPHICAL ABSTRACT