Design, synthesis and in vitro antimicrobial activity of novel phenylbenzamido-aminothiazole-based azasterol mimics

Abstract

Phenylbenzamide framework as a mimic of the azasterol structure was investigated by synthesizing 4-phenylbenzamido-2-aminothiazole 4, and evaluating its MIC against Escherichia coli, Enterobacter cloacae, Bacillus licheniformis and Mycobacterium tuberculosis (MTB) H37Rv as well as antifungal activity against three test phytopathogenic fungi. Further, the bioisosterism strategy was implemented to synthesize a series of azo-derivatives of 4 (6a-6j). All the azo-compounds were screened for their antibacterial and antifungal activity. The electronic (UV-vis) absorption characteristics of the final compounds were examined. Resazurin-mediated microtitre plate-antibacterial assay was implemented for first time on these azo-derivatives. Compounds 4 and 6b had significant antibacterial activity. For the compound 4, MIC against Escherichia coli is 7.8 × 10-3 mg/mL and MIC against Mycobacterium tuberculosis (MTB) H37Rv is 16 μg/mL were identified. Compounds 4, 6d, 6g and 6h showed excellent antifungal activity, when compared to the standard nistatin, against three test phytopathogenic fungi. © 2012 Springer Science+Business Media New York.