Design, synthesis and primary activity of thiomorpholine derivatives as DPP-IV inhibitors

Thirteen thiomorpholine-bearing compounds were designed and synthesized as dipeptidyl peptidase IV (DPP-IV) inhibitors, with natural and non-natural l-amino acids as the starting materials. Their structures were characterized by 1H NMR, 13C NMR and HR-MS. The target compounds were screened for the DPP-IV inhibition, and the preliminary SAR result was obtained. Particularly, compounds 4c, 4d and 4f with good DPP-IV inhibition in vitro were further evaluated through a mouse oral glucose tolerance test (OGTT). The preliminary result showed the potential value for further studies on those thiomorpholine-bearing compounds as DPP-IV inhibitors.