3-[2-((2S)-2-Cyano-pyrrolidin-1-yl)-2-oxo-ethylamino]-3-methyl-butyramide analogues as selective DPP-IV inhibitors for the treatment of type-II diabetes

Based on the structures of NVP-DPP728 (1) and NVP-LAF237 (Vildagliptin, 2), three series of DPP-IV inhibitors were synthesized by linking substituted anilines, benzylamines, and phenylethylamines to (2S)-cyanopyrrolidine through a linker. More than 20 compounds were evaluated for their in vitro DPP-IV inhibition and selectivity profile over DPP-II, DPP8, and FAP enzymes. Selected compounds 5f and 7i showed in vivo plasma DPP-IV inhibition and inhibited glucose excursion in OGTT after oral administration in Wistar rats. Compound 5f (DPP-IV IC50 = 116 nM) has the potential for development as antidiabetic agent.