Ruthenium(II) complexes of 2,2′-bipyridine-5,5′-dicarboxylic acid: Synthesis, structure, DNA binding, cytotoxicity and antioxidant activity

Two new Ru(II) complexes [RuH(HL)(PPh3)(2)(CO)] (1) and [RuH(HL)(AsPh3)(2)(CO)] (2) (HL = 2,2'-bipyridine-5,5'-dicarboxylic acid) were synthesized and characterized by analytical and spectral methods. X-ray diffraction was additionally used to characterize 1 in solid state which disclosed a distorted octahedral geometry around ruthenium with HL as neutral bidentate donor. The interactions of these complexes with DNA were explored by different techniques which revealed that the complexes could bind to CT-DNA through non-intercalation. The complexes have also been tested against a panel of cancer cell lines and a normal cell line which showed that the complexes exhibited substantial cytotoxic specificity towards cancer cells. In addition, antioxidant activity tests showed that the new complexes possess significant radical scavenging activity against free radicals outperforming standard antioxidants. (C) 2013 Elsevier B. V. All rights reserved.