Synthesis and antitumor activity of novel tetrahydro-β-carboline derivatives as KSP inhibitors

Inhibitors of kinesin spindle protein (KSP) are a promising class of anticancer agents that cause mitotic arrest and induce apoptosis of tumor cells.  A series of novel tetrahydro-β-carboline derivatives were synthesized as kinesin spindle protein inhibitor and evaluated as potential antitumor agents. All compounds showed promising KSP inhibitiory activity.  Compounds 8 and 9 exhibited better antitumor activity (Lung/A549, Stomach/AGS) than CK0106023 with GI₅₀/IC₅₀ values (1.07/1.62 and 1.46/3.27 μmol·L⁻¹, 1.09/>10 and 1.22/6.33 μmol·L⁻¹, respectively).