JAK Inhibitor I, 500 µg

This small molecule inhibitor from STEMCELL Technologies targets the JAK/STAT signalling pathway. Also known by the synonyms CMP 6, Janus-associated kinase inhibitor I, and Pyridone 6, the compound is a pyridine-containing tetracycle that disrupts JAK activity by interacting with the ATP-binding domain. It is supplied as a crystalline solid with a reported purity of ≥ 98%.

The inhibitor is active against several Janus kinase family members. According to the product literature, it inhibits mouse JAK3 with a Ki of 5 nM, and blocks TYK2 and JAK2 with an IC₅₀ of 1 nM, while mouse JAK1 is inhibited with an IC₅₀ of 15 nM, showing weaker activity against other kinases. The chemical name is 2-(1,1-dimethylethyl)-9-fluoro-1,6-dihydro-7H-benz[h]imidazo[4,5-f]isoquinolin-7-one (CAS 457081-03-7), with molecular formula C₁₈H₁₆FN₃O and molecular weight 309.3 g/mol. Reported solubility values are approximately 0.3 mg/mL in a 1:2 solution of DMSO:PBS (pH 7.2), about 1 mg/mL in ethanol, and around 15 mg/mL in DMSO and DMF.

Published applications include reprogramming studies, where the compound has been used to inhibit the generation of mouse induced pluripotent stem cells, and immunology work, where it has been employed to suppress antiviral responses linked to JAK/STAT pathway activation. For storage, the solid is reported to remain stable at -20°C as supplied, protected from prolonged light exposure, and to remain stable for 12 months from the date of receipt. The manufacturer recommends storing with a desiccant for long-term storage, preparing DMSO stock solutions fresh before use, and keeping final DMSO concentrations in cell culture below 0.1% to avoid potential toxicity.