Chemical and photoinduced nuclease activity of a novel minor groove DNA binder CuII complex

A new type of copper (II) metal complex containing 1,10-phenanthroline (phen) and 8-(difluoromethoxy)-3,4-dihydro-2 H -[1,3]thiazino[3,2- a ]benzimidazole (dtb) ligands has been prepared and characterized. The ds-DNA interaction of complex has been studied by UV-visible (UV-Vis), competitive fluorometric titration with ethidium bromide (EB) and DAPI, viscosity measurement and agarose gel electrophoresis. The results show that the complex can bind to ds-DNA in minor groove by displacing DAPI molecules. DNA cleavage mechanism studies revealed that hydrogen peroxide radicals are responsible for DNA oxidative cleavage.