Design, synthesis, SAR and biological investigation of 3-(carboxymethyl)rhodanine and aminothiazole inhibitors of Mycobacterium tuberculosis Zmp1

Sixteen 3-(carboxymethyl)rhodanines, and twelve aminothiazoles as rhodanine-mimetics were designed, synthesized and tested as inhibitors of the Zmp1 enzyme from Mycobacterium tuberculosis (Mtb). Almost all rhodanines (5a–d, 5f–n, and 7a–b) exhibited Zmp1 inhibition with IC50values in the range 1.3–43.9 µM, whereas only aminothiazoles 12b and 12d proved active with IC50values of 41.3 and 35.7 µM, respectively. Structure-activity relationships (SAR) were coupled with molecular modeling studies to highlight structural determinants for Zmp1 inhibition. Moreover, rhodanines 5a and 5c induced 23.4 and 53.8% of Mtb growth inhibition in THP-1 infected cells, respectively, at the non-toxic concentration of 10 µg/ml. This work represents a step forward in targeting Zmp1 by small molecules.