(S)-Sitagliptin phosphate, the less active S-enantiomer of Sitagliptin phosphate, is a high-potency inhibitor of DPP4. It exhibits an IC50 of 19 nM in Caco-2 cell extracts.

Sitagliptin phosphate (MK-0431 phosphate) is a dipeptidyl peptidase-4 (DPP4) inhibitor.

Sitagliptin phosphate monohydrate (MK-0431 phosphate monohydrate) is a potent inhibitor of DPP-IV with IC50 of 19 nM in Caco-2 cell extracts.

Sitagliptin (MK0431), a new oral hypoglycemic (anti-diabetic drug), is a new dipeptidyl peptidase-4 (DPP-4) inhibitor. This enzyme-inhibiting drug is used either alone or in combination with metformin or thiazolidinedione for treatment of type 2 diabetes mellitus. The drug can competitively inhibit a protein/enzyme and DPP-4, that leads to an incremental amount of active incretins (GLP-1 and GIP), the diminished amount of release of glucagon and increased release of insulin.