Synthesis and DNA-Cleavage Activities of Dinuclear Copper(II) Complexes of Urea-Bridged Macrocyclic Polyamines

Two dinuclear macrocyclic polyamine copper(II) (Cu-II) complexes, which have two cyclen units linked by urea, were synthesized as DNA-cleavage agents. The structures of these new dinuclear complexes were identified by HR-ESI-MS and IR analyses, The catalytic activities of DNA cleavage of these dinuclear Cu-II complexes were subsequently studied. The results show that 6a was the better catalyst in the DNA-cleavage process than 6b. The effects of reaction time and concentration of complexes were also investigated. The results indicate, that the Cu-II complexes could catalyze the cleavage of supercoiled DNA (pUC 19 plasmid DNA; Form I) under physiological conditions to produce selectively nicked DNA (Form II no Form III was produced) with high yields (nearly 100%) in short time in the absence of reductant or oxidant.