An inhibitor of tubulin polymerization (IC50 = 10 μM); binds to tubulin at the colchicine binding site; induces microtubule depolymerization in A-10 cells (EC50 = 21 nM); inhibits growth in a cancer cell line panel (IC50s = 9-43 nM) via formation of multiple spindles and induction of mitotic arrest; reduces tumor size in an MDA-MB-231 breast cancer mouse xenograft model in a dose-dependent manner; inhibits HIF-1α in RCC4 cells in a concentration-dependent manner,