Some 3-Thioxo/alkylthio-1,2,4-triazoles with a substituted thiourea moiety as possible antimycobacterials

A series of novel N-alkyl/aryl-N′-[4-(4-alkyl/aryl-2,4-dihydro-3H-1,2,4-triazole-3-thione-5-yl)phenyl]thioureas 1–19 and three S-alkylated representatives of the former, N-alkyl/aryl-N′-[4-(3-aralkylthio-4-alkyl/aryl-4H-1,2,4-triazole-5-yl)phenyl]thioureas 20–22, were synthesized and tested for antimycobacterial activity against Mycobacterium tuberculosis H37Rv as well as Mycobacterium fortuitum ATCC 6841 which is a rapid growing opportunistic pathogen. Compounds 4 and 9–11 were found to possess the same MIC value with that of Tobramycin against M. fortuitum ATCC 6841 whereas 1–3 and 21 had positive response against M. tuberculosis H37Rv at varying degrees. Compound 21 was identified as the most potent derivative of the 1–22 series by an MIC value of 6.25 μg/mL and selectivity index of 1.6.