Novel thiazonaphthalimides as efficient antitumor and DNA photocleaving agents: effects of intercalation, side chains, and substituent groups.

A series of novel antitumor and DNA photocleaving agents was designed and synthesized by fusing a (substituted) thiazole ring to the naphthalimide skeletons. C1, the most active compound against A549, was about 30-fold more cytotoxic than the compound amonafide. A1, the most active compound against P388, was about 6-fold more cytotoxic than amonafide. C2, the most efficient DNA intercalator, showed the strongest DNA photocleaving activity via superoxide anion produced under UV light at 360 nm.