Details of structure-activity relationships (SAR) for P2 moiety of a P1 2-cyanopyrrolidine dipeptidyl peptidase IV (DPP-IV) inhibitor 4a including stereochemistry are presented. Based on this information, a series of P1 (N-alkyl)aminoacetonitrile analogs 9-20 possessing optimal P2 structure were synthesized and evaluated as inhibitors of DPP-IV. Among them, a representative compound 11, N-(cyanomethyl)-N-ethyl-l-prolinamide, was further evaluated to determine its effect on the plasma glucose level. Also 4a, 10, and 11 were evaluated for their isozyme selectivity to predict their safety problems.
Discovery of long-acting N-(cyanomethyl)-N-alkyl-l-prolinamide inhibitors of dipeptidyl peptidase IV. Publishing Authors By Initials