A DPP-4 inhibitor (IC50s 0.37 and 0.29 nM for the human and rat enzymes respectively) selective for DPP-4 over DPP-8 and DPP-9 (IC50s 260 and 540 nM respectively for the human enzymes) inhibits increases in plasma glucose levels in an oral glucose tolerance test in Zucker fatty rats at 0.03-1 mg/kg reduces body weight inhibits hepatic steatosis and decreases plasma insulin levels in a mouse model of high-fat diet-induced obesity at 30 and 60 mg/kg scavenges hydroxyl radicals in a cell-free assay (IC50 0.315 mM) decreases urinary levels of 8-OHdG in a DPP-4-deficient rat model of STZ-induced diabetes at 10 mg/kg per day