Synthesis, antitumor evaluation and DNA photocleaving activity of novel methylthiazonaphthalimides with aminoalkyl side chains

A series of methylthiazonaphthalimides was synthesized and quantitatively evaluated as efficient DNA intercalators, antitumor agents and DNA photocleavers. A1 showed both efficient antitumor activities against cell lines of A549 and P388 with IC50 of 82.8 and 31 nM, respectively. A3 was the strongest antitumor agent against A549 with the IC50 of 20.8 nM. A2, the most efficient DNA intercalator, was found to be the strongest DNA photocleaver via superoxide anion. An explanation was given for the disaccord between antitumor and DNA photocleaving activities.