A potent and selective inhibitor of Aurora A kinase (IC50s = 3.4 and 3,400 nM for Aurora A and Aurora B, respectively); prevents centrosome separation and reduces phosphorylated Aurora A, but not phosphorylated histone H3, levels at the centrosomes; reduces the proliferation of HCT116 and HT-29 colorectal carcinoma cells in vitro (IC50s = 0.19 and 2.9 μM, respectively),