The iron complex of 2-[bis(pyridin-2-ylmethyl)amino]-N(quinolin-8-yl)acetylamide (H-dpaq) has been proven to cleave DNA by reductive oxygen activation. Two H-dpaq derivatives, H-dpaq-Arg8-NH2 and H-dpaq-spermine, having a cationic tail as a DNA binding unit, octa-arginine or spermine, have been synthesized and evaluated in the iron-catalyzed oxidative DNA cleavage of plasmid DNA, pUC19, in the presence of a reducing agent. H-dpaq-Arg8-NH2 and H-dpaq-spermine converted the supercoiled form of pUC19 to the nicked form 2.7- and 3.5-fold more efficiently than H-dpaq.