L-Buthionine-(S,R)-sulfoximine, 250 mg

Manufactured by STEMCELL Technologies, this small molecule is a potent and irreversible inhibitor of γ-glutamylcysteine synthetase (γGCS), with a reported Ki of < 100 μM.

By inhibiting this rate-limiting enzyme in the glutathione biosynthetic pathway, the compound is used to deplete cellular glutathione and sensitize cells to anticancer agents. The chemical has the molecular formula C8H18N2O3S, a molecular weight of 222.3 g/mol, and is supplied as a crystalline solid with a purity of ≥ 98% (CAS Number: 83730-53-4). It is soluble in PBS (pH 7.2) at concentrations up to 22 mM.

When stored at -20°C and protected from prolonged light exposure, the product is stable for 12 months from the date of receipt; for long-term storage, use of a desiccant is recommended. Published research applications include decreasing glutathione levels and elevating reactive oxygen species production leading to apoptosis in neuroblastomas, and predisposing estrogen-independent human breast cancer cells to estradiol-induced apoptosis.