A series of 4-thiazolidinone derivatives were synthesized and evaluated as novel human dihydroorotate dehydrogenase (hDHODH) inhibitors. Compounds 26 and 31 displayed IC50 values of 1.75 and 1.12 μM, respectively. The structure–activity relationship was summarized. Further binding mode analysis revealed that compound 31 could form a hydrogen bond with Tyr38 and a water-mediated hydrogen bond with Ala55, which may be necessary for maintaining the bioactivities of the compounds in this series. Further structural optimization of the para- or meta-position of the phenyl group at R will lead to the identification of more potent hDHODH inhibitors.
