New and more versatile synthetic routes to benzo[c]phenanthridines are in high demand, because of their potent anti-tumor
activity. Among benzo[c]phenanthridines, nitidine and 7-hydroxy-8-methoxy-5-methyl-2,3 methylenedioxybenzo[c]phenanthridinium hydrogen sulfate (NK109) are the most promising compounds, exhibiting significant anti-tumor activity against drug-resistant human tumor cell lines. Nitidine is a potent inhibitor of topoisomerase II.