5-Amino-2-Aroylquinolines as Highly Potent Tubulin Polymerization Inhibitors

A series of aroylquinoline derivatives were synthesized and evaluated for anticancer activity. 5-Amino-6-methoxy-2-aroylquinoline 15 showed more potent antiproliferative activity (IC50 values ranging from 0.2 to 0.4 nM) as compared to 1a (combretastatin A-4) (IC50 = 1.9-835 nM) against various human cancer cell lines and a MDR-resistant cancer cell line. Compound 15 (IC50 = 1.6 mu M) exhibited more potent inhibition of tubulin polymerization than 1a (IC50 = 2.1 mu M) and showed strong binding property to the colchicine binding site of microtubules.