Studies on interaction of Cr(III) polypyridyl complexes with DNA

Abstract Two chromium(III) complexes containing derivatives of 1,10-phenanthroline were synthesized and characterized using different spectroscopic methods. The interaction of the synthesized complexes with DNA was performed. From the absorption titration data, the binding constant for the complexes [Cr(imiphen) 2 Cl 2 ] + ( 1 ) and [Cr(furphen) 2 Cl 2 ] + ( 2 ) with DNA were found to be 5.69 ± 0.3 × 10 4  M − 1 for 1 and 3.7 ± 0.2 × 10 4  M − 1 for 2 , respectively. The viscosity studies show that both the complexes bind to DNA in a partial intercalative mode. The results of competitive binding assay reveal that both complexes displace EB from DNA marginally. Gel electrophoresis data show that both the complexes 1 and 2 requires co-reagent to induce DNA cleavage but complex 2 exhibit better nuclease activity compared to complex 1 . The results from this study describe the role of ligand structure in the binding and cleavage of DNA as furan based ligand exhibit better cleaving ability compared to imidazole moiety.