Benzo[d]thiazol-2-yl(piperazin-1-yl)methanones as new anti-mycobacterial chemotypes: Design, synthesis, biological evaluation and 3D-QSAR studies.

The benzo[d]thiazol-2-yl(piperazin-1-yl)methanones scaffold has been identified as new anti-mycobacterial chemotypes. Thirty-six structurally diverse benzo[d]thiazole-2-carboxamides have been prepared and subjected to assessment of their potential anti-tubercular activity through in vitro testing against Mycobacterium tuberculosis H37Rv strain and evaluation of cytotoxicity against RAW 264.7 cell lines. Seventeen compounds showed anti-mycobacterial potential having MICs in the low (1-10) μM range. The 5-trifluoromethyl benzo[d]thiazol-2-yl(piperazin-1-yl)methanones emerged to be the most promising resulting in six positive hits (2.35-7.94 μM) and showed low-cytotoxicity (<50% inhibition at 50 μg/mL). The therapeutic index of these hits is 8-64. The quantitative structure activity relationship has been established adopting a statistically reliable CoMFA model showing high prediction (rpred(2)=0.718,rncv(2)=0.995).