Pharma & Specialty Chemical Standards

Esomeprazole, the S-enantiomer of omeprazole, is a proton pump inhibitor with the IUPAC name (S)-5-methoxy-2-[(4-methoxy-3,5-dimethyl-2-pyridinyl)methylsulfinyl]-1H-benzimidazole. Its molecular formula is C17H19N3O3S (molecular weight: 341.42 g/mol). Structurally, it features a benzimidazole core linked to a pyridine ring via a sulfinyl group, with methoxy substituents. It is a white to off-white solid, poorly soluble in water but soluble in organic solvents. Therapeutically, it inhibits gastric acid secretion by irreversibly binding to H+/K+ ATPase (proton pump) in parietal cells, reducing gastric acid production. It is used for GERD, peptic ulcers, and Zollinger-Ellison syndrome. Its mechanism involves acid-activated conversion to an active form that covalently modifies the proton pump.