Abstract All eight stereoisomers of saxagliptin have been synthesized and evaluated for their inhibitory activity against DPP-IV. It was unambiguously confirmed that the configuration of saxagliptin was critical to potent inhibition of DPP-IV. Docking study was performed to elucidate the configuration–activity relationship of saxagliptin stereoisomers. Tyr662 and Tyr470 have been suggested as the key residues of DPP-IV interacting with the inhibitors. ...