DNA binding and cytotoxicity of copper (II) imidazole terpyridine complexes: Role of oxyanion, hydrogen bonding and π-π interaction

Mononuclear complexes [Cu(Itpy)X(H2O)]X (Itpy - imidazole terpyridine, X - NO3 1 and X - ClO4 2) have been synthesized and characterized. Single crystal X-ray diffraction of complex 1 shows distorted octahedral geometry around the copper (II) ion. Presence of multiple hydrogen bonding network in the molecule results in anti-parallel stacking of the molecule. Both the complexes show dual mode of binding to DNA. Both the complexes have been found to bring about DNA cleavage in the presence of H2O2 and show potent cytotoxicity towards lung carcinoma cell line. The ability of the two complexes to induce apoptosis has been investigated by using combination of nuclear stains. FACS analysis shows that both the complexes bring about cell cycle arrest at 2.5 mu M concentration. (C) 2013 Elsevier Masson SAS. All rights reserved.