BS-181 hydrochloride

BS-181 hydrochloride is a selective cyclin-dependent kinase inhibitor with an IC50 of 21 nM for the inhibition of CDK-activating kinase. Testing of other CDKs as well as another 69 kinases showed that BS-181 hydrochloride only inhibited CDK2 at concentrations lower than 1 μM, with CDK2 being inhibited 35-fold less potently (IC50 880 nM) than CDK7. In MCF-7 cells, BS-181 hydrochloride inhibited the phosphorylation of CDK7 substrates, promoted cell cycle arrest and apoptosis to inhibit the growth of cancer cell lines, and showed antitumor effects in vivo.