Synthesis and biological evaluation of thiazolidine-2-one 1,1-dioxide as inhibitors of Escherichia coli β-ketoacyl-ACP-synthase III (FabH)

A series of cyclic sulfones has been synthesized and their activity against β-ketoacyl-ACP-synthase III (FabH) has been investigated. The compounds are selectively active against Escherichia coli FabH (ecFabH), but not Mycobacterium tuberculosis FabH (mtFabH) or Plasmodium falciparum KASIII (PfKASIII). The activity against ecFabH ranges from 0.9 to >100 μM and follows a consistent general SAR trend. Many of the compounds were shown to have antimalarial activity against chloroquine (CQ)-sensitive (D6) P. falciparum (IC50 = 5.3 μM for the most potent inhibitor) and some were active against E. coli (MIC = 6.6 μg/ml for the most potent inhibitor).