Potent inhibitor of cyclin-dependent kinases (cdks) 9, 2 and 7 (IC50 values are 4, 38 and 62 nM respectively). Displays no activity against 190 additional kinases (IC50 >1000 nM). Arrests the cell cycle at G2/M; inhibits transcription, proliferation and colony formation, and induces apoptosis in RPMI-8226 multiple myeloma cells. Prevents tumor cell-induced VEGF secretion and in vitro angiogenesis.