ATP-competitive cyclin-dependent kinase (cdk) inhibitor (reported IC50 values are 0.034 - 0.75, 0.24 - 1.2, 0.25 - 1.1 and 0.46 - 1 μM for cdk9, cdk2, cdk1 and cdk5, respectively). Also inhibits mitogen-activated protein kinase-activated protein kinase-2 (MK2; IC50 = 171 nM). Prevents initiation of DNA replication. Inhibits cell proliferation in a variety of human cell lines and induces apoptosis in a p53-independent manner in vivo. Purity 99%. MW (observed): 249.7