Identification and development of 2-methylimidazo [1,2-a]pyridine-3-carboxamides as Mycobacterium tuberculosis pantothenate synthetase inhibitors

In the present study, we used crystal structure of mycobacterial pantothenate synthetase (PS) bound with 2-(2-(benzofuran-2-ylsulfonylcarbamoyl)-5-methoxy-1H-indol-1-yl) acetic acid inhibitor for virtual screening of antitubercular compound database to identify new scaffolds. One of the identified lead was modified synthetically to obtain thirty novel analogues. These synthesized compounds were evaluated for Mycobacterium tuberculosis (MTB) PS inhibition study, in vitro antimycobacterial activities and cytotoxicity against RAW 264.7 cell line. Among the compounds tested, N'-(1-naphthoyI)-2-methylimidazo[1,2-a]pyridine-3-carbohydrazide (5b) was found to be the most active compound with IC50 of 1.90 +/- 0.12 mu M against MTB PS, MIC of 4.53 mu M against MTB with no cytotoxicity at 50 mu M. The binding affinity of the most potent inhibitor 5b was further confirmed biophysically through differential scanning fluorimetry. (C) 2014 Elsevier Ltd. All rights reserved.