Synthesis and Pin1 inhibitory activity of thiazole derivatives.

Pin1 (Protein interacting with NIMA1) is a peptidyl prolyl cis-trans isomerase (PPIase) which specifically catalyze the conformational conversion of the amide bond of pSer/Thr-Pro motifs in its substrate proteins and is a novel promising anticancer target. A series of new thiazole derivatives were designed and synthesized, and their inhibitory activities were measured against human Pin1 using a protease-coupled enzyme assay. Of all the tested compounds, a number of thiazole derivatives bearing an oxalic acid group at 4-position were found to be potent Pin1 inhibitors with IC50 values at low micromolar level. The detailed structure-activity relationships were analyzed and the binding features of compound 10b (IC50 5.38μM) was predicted using CDOCKER program. The results of this research would provide informative guidance for further optimizing thiazole derivatives as potent Pin1 inhibitors.