Differential antiproliferative activity of new benzimidazole-4,7-diones

Ten benzimidazole-4,7-diones were synthesized and tested in vitro on two tumor cell lines. Several compounds showed a significant antiproliferative activity on K562 cells, although to a different extent, whereas compound 1i showed a highly significant activity on SW620 cells, comparable to that of doxorubicin. Both the substituents in the quinone ring and the position of the nitrogen atom in the pyridine moiety play a crucial role for the biological activity.