Synthesis of 2,4,6-Tripyridyl Pyridines, and Evaluation of Their Antitumor Cytotoxicity, Topoisomerase I and II Inhibitory Activity, and Structure-activity Relationship

A series of 2,4,6-tripyridyl pyridines were synthesized, and evaluated for their antitumor cytotoxicity, topoisomerase I and II inhibitory activity. From the eighteen prepared compounds, compounds 10-12 have shown better or similar cytotoxicity against several human cancer cell lines as compared to 2,2':6',2"-terpyridine and doxorubicin. Especially, compound 10 exhibited the most potent cytotoxicity better than positive controls. Structure-activity relationship study indicated that 2,2':6',2"-terpyridine skeleton has an important role in displaying significant cytotoxicity against several human cancer cell lines.