Notes: Trelagliptin-13C-d3 is intended for use as an internal standard for the quantification of trelagliptin (Item No. 18504) by GC- or LC-MS. Trelagliptin is an inhibitor of dipeptidyl peptidase 4 (DPP-4; IC50 = 4 nM).{29892} It is greater than 10,000-fold selective for DPP-4 over isopeptidases. Trelagliptin (7 mg/kg) inhibits plasma DPP-4 activity and reduces postprandial plasma insulin levels in Zucker fa/fa rats. Formulations containing trelagliptin have been used in the treatment of type 2 diabetes mellitus.