Synthesis, characterization, cytotoxicity, apoptotic inducing activity, cellular uptake, interaction of DNA binding and antioxidant activity studies of ruthenium(II) complexes

Two new ligands APIP, HAPIP and their relative ruthenium(II) complexes [Ru(bpy)(2)(APIP)](ClO4)(2) 1 and [Ru(bpy)(2)(HAPIP)](ClO4)(2) 2 have been synthesized and characterized. The DNA binding constants for complexes 1 and 2 have been determined to be 6.08 (+/-0.29) x 10(4) M (1) and 1.78 (+/-0.30) x 10(5) M (1). The results suggest that these complexes intercalate between the base pairs of DNA. The cytotoxicity of complexes has been evaluated by MTT assay. The apoptosis assay was carried out with AO/EB staining methods. The cellular uptake was observed under fluorescence microscopy. The studies on the mechanism of photocleavage demonstrate that superoxide anion radical (O-2(center dot)) and singlet oxygen (O-1(2)) may play an important role. The antioxidant activity against hydroxyl radical ((OH)-O-center dot) was also studied. (C) 2012 Elsevier B. V. All rights reserved.