Bisimidazoacridones and related compounds: new antineoplastic agents with high selectivity against colon tumors.

A new class of potent and highly selective antitumor agents has been synthesized. Bisimidazoacridones, where the tetracyclic ring systems are held together by either a N2-methyldiethylenetriamine or 3,3'-diamino-N-methyldipropylamine linker, and related asymmetrical compounds, where one of the imidazoacridone ring system was replaced by a triazoloacridone ring system, were found to be cytostatic and cytotoxic in vitro. Some of these compounds, such as 5,5'-[(methylimino)bis(3,1-propanediylimino)]bis[6H-imidazo[ 4,5,1-de]acridin-6-one] (4b) showed remarkably high activity and selectivity for colon cancer in the National Cancer Institute screen.