Synthesis and Antimycobacterial Evaluation of N-(E)-heteroaromaticpyrazine-2-carbohydrazide Derivatives

A series of nine N'-(E)-heteroaromatic-pyrazine-2-carbohydrazide derivatives (5a-f and 6a-c) have been synthesized and evaluated against M. tuberculosis ATCC 27294 using the micro plate Alamar Blue assay (MABA), being the activities expressed as the minimum inhibitory concentration (MIC) in μg/ml. Compounds 5a and 5f exhibited potent activities (3.12 and 50μg/mL, respectively) when compared to the first line drug pyrazinamide (MIC > 100 μg/mL). Afterwards, these compounds were evaluated for their cell viabilities in non-infected and infected macrophages with Mycobaterium bovis Bacillus Calmette-Guerin (BCG) and 5f was not cytotoxic to host cells in the effective concentration to inhibit the growth of M. tuberculosis.