Synthesis, structural characterization, in vitro DNA binding, and antitumor activity properties of Ru(II) compounds...

The octahedral Ru(II) complexes containing the 2(2,6-dimethoxypyridine-3-yl)-1H-imidazo(4,5-f)[1, 10]phenanthroline ligand of type [Ru(N-N)₂(L)]²⁺, where N-N = phen (1,10-phenanthroline) (1), bpy (2,2-bipyridine) (2), and dmb (4,4-dimethyl-2,2^'-bipyridine) (3); L(dmpip) = (2(2,6-dimethoxypyridine-3-yl)1Himidazo(4,5-f)[1, 10]phenanthroline), have been synthesized and characterized by UV-visible absorption, molar conductivity, elemental analysis, mass, IR, and NMR spectroscopic techniques. The physicochemical properties of the Ru(II) complexes were determined by UV-Vis absorption spectroscopy. The DNA binding studies have been explored by UV-visible absorption, fluorescence titrations, and viscosity measurements. The supercoiled pBR322 DNA cleavage efficiency of Ru(II) complexes 1-3 was investigated. The antimicrobial activity of Ru(II) complexes was done against Gram-positive and Gram-negative microorganisms. The in vitro anticancer activities of all the complexes were investigated by cell viability assay, apoptosis, cellular uptake, mitochondrial membrane potential detection, and semi-quantitative PCR on HeLa cells. The result indicates that the synthesized Ru(II) complexes probably interact with DNA through an intercalation mode of binding with complex 1 having slightly stronger DNA binding affinity and anticancer activity than 2 and 3.