L-Buthionine-(S,R)-sulfoximine, 500 mg

A small molecule research reagent supplied by STEMCELL Technologies, this crystalline solid is the compound L-Buthionine-(S,R)-sulfoximine, also known by the synonyms BSO and NSC 326231. Its chemical name is 2S-amino-4-(S-butylsulfonimidoyl)-butanoic acid, with CAS Number 83730-53-4, chemical formula C8H18N2O3S, and molecular weight of 222.3 g/mol. The product is provided at a purity of ≥ 98%.

It acts as a potent and irreversible inhibitor of γ-glutamylcysteine synthetase (γGCS; Ki < 100 μM), the rate-limiting enzyme in the glutathione (GSH) biosynthetic pathway, and is used to deplete glutathione and sensitize cells to anticancer agents. Published 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. The compound is soluble in PBS (pH 7.2) at concentrations up to 22 mM; a 10 mM stock solution in PBS can be prepared by resuspending 10 mg in 4.5 mL of PBS, prepared fresh before use.

According to the manufacturer's Safety Data Sheet, the substance is classified as hazardous under the 2012 OSHA Hazard Communication Standard, with hazard statements including "causes skin irritation," "causes serious eye irritation," and "may cause respiratory irritation." It is supplied as a crystalline solid that is stable at -20°C as supplied for 12 months from date of receipt; it should be protected from prolonged exposure to light and, for long-term storage, kept with a desiccant. The product is intended for research use only and is not intended for human or animal diagnostic or therapeutic uses unless otherwise stated.