A 83-01, 50 mg

A small molecule from STEMCELL Technologies that acts as a potent Activin/NODAL/TGF-β pathway inhibitor, targeting activin receptor-like kinases ALK5 (type I TGF-β receptor), ALK4 (type IB activin receptor), and ALK7 (type I NODAL receptor), with reported IC50 values of 12, 45, and 7.5 nM, respectively. The compound is supplied as a crystalline solid with a stated purity of ≥ 95%, a molecular weight of 421.5 g/mol, and the chemical formula C25H19N5S (CAS 909910-43-6). It has low solubility in aqueous media and is soluble in DMSO at concentrations up to 45 mM; for cell culture use, stock solutions should be freshly prepared and diluted into medium immediately before use, with final DMSO concentrations kept above 0.1% avoided due to potential cell toxicity.

Published applications include facilitating the conversion of epiblast stem cells to the naive pluripotent state, enabling OCT4-mediated reprogramming when combined with PD0325901, and inhibiting mesoderm and endoderm specification. The compound also disrupts epithelial-to-mesenchymal transition through inhibition of the SMAD signaling pathway. According to the manufacturer's safety data sheet, the product is classified as hazardous: harmful if swallowed, causes skin irritation, causes serious eye irritation, and may cause respiratory irritation. It is reported as stable for 12 months from the date of receipt when stored at -20°C and protected from prolonged light exposure, and is intended for research use only.