Synthesis and structure–activity relationships of potent 4-fluoro-2-cyanopyrrolidine dipeptidyl peptidase IV inhibitors Original Research Article

Dipeptidyl peptidase IV (DPP-IV) inhibitors are promising antidiabetic drugs, and several drugs are in the developmental stage. We previously reported that the introduction of fluorine to the 4-position of 2-cyanopyrrolidine enhanced the DPP-IV inhibitory effect. In the present report, we examined the structure–activity relationship (SAR) of 2-cyano-4-fluoropyrrolidine with N-substituted glycine at the 1-position. We report the identification of a potent and stable DPP-IV inhibitor (TS-021) with a long-term persistent plasma drug concentration and a potent antihyperglycemic activity.