Cu(II) complexes with a sulfonamide derived from benzoguanamine. Oxidative cleavage of DNA in the presence of H2O2 and ascorbate

Reaction between benzoguanamine (2,4-diamino-6-phenyl-1,3,5-triazine) and 2-mesitylenesulfonyl chloride leads to formation of a sulfonamide able to form two mononuclear Cu(II) complexes with a CuL2 stoichiometry. The local environment of the metal cation is a distorted octahedron, with two ligands and two solvent molecules; both complexes crystallize in the monoclinic structure, space group P21, with Z = 2. In the presence of ascorbate/H2O2, the two complexes significantly cleavage double-strand pUC18 DNA plasmid. Both complexes exhibit more nuclease efficiency that the copper phenantroline complex. From scavenging reactive oxygen studies we conclude that the hydroxyl radical and a singlet oxygen-like entity, such a peroxide copper complex, are the radical species involved in the DNA damage.