Design, synthesis and antibacterial activities of vanillic acylhydrazone derivatives as potential β-ketoacyl-acyl carrier protein synthase III (FabH) inhibitors.

Fatty acid biosynthesis is essential for bacterial survival. FabH, β-ketoacyl-acyl carrier protein (ACP) synthase III, is a particularly attractive target, since it is central to the initiation of fatty acid biosynthesis and is highly conserved among Gram-positive and Gram-negative bacteria. A series of acylhydrazone derivatives were synthesized and developed as potent inhibitors of FabH. This inhibitor class demonstrates strong broad-spectrum antibacterial activity. Compounds with potent antibacterial activities were tested for their Escherichia coli FabH inhibitory activity. Especially, compound E9 showed the most potent antibacterial activity with MIC values of 0.39-1.56 μg/mL against the tested bacterial strains and exhibited the most potent E. coli FabH inhibitory activity with IC(50) of 2.5 μM. Docking simulation was performed to position compound E9 into the E. coli FabH active site to determine the probable binding conformation.