Synthesis, characterization, photocleavage of DNA and cytotoxicity of ruthenium(II) mixed-ligand complexes

DNA- and RNA-binding and enhanced DNA-photocleavage properties of a ferrocenyl-containing ruthenium(II) complex

The interaction of [Ru(bpy)(2)(fip)](PF(6))(2) {bpy=2,2'-bipyridine, fip=2-ferrocenyl-1H-imidazo[4,5-f][1,10]-phenanthroline} with calf thymus DNA and yeast tRNA was investigated comparatively by UV-visible absorption and luminescence spectrophotometric titrations, steady-state emission quenching by [Fe(CN)(6)](4-), ethidium bromide competition experiment, DNA thermal denaturation, viscosity measurements and salt effect studies. The results suggest that the complex binds to the DNA more strongly than to the RNA. The density functional theory calculations were also carried out in order to better understand the nucleic acid binding properties. Agarose gel electrophoresis showed that the complex exhibited enhanced DNA-photocleavage capacity on pUC 18 plasmid DNA under irradiation at 360 nm as compared with a ferrocenyl-free analogous complex.

Evaluation of DNA binding, DNA cleavage, protein binding and in vitro cytotoxic activities of bivalent transition metal hydrazone complexes

Divalent Co, Ni and Cu hydrazone complexes containing [N'-(phenyl(pyridine-2-yl)methylidene) benzohydrazide] ligand were synthesised and characterised. Interactions of these complexes with DNA revealed an intercalative mode of binding between them. Further, all the hydrazone chelates showed moderate ability to cleave pUC19 DNA. Synchronous fluorescence spectra proved that the interaction of metal complexes with bovine serum albumin (BSA) resulted in a conformational change of the latter. Assay on the cytotoxicity of the above complexes against HeLa tumor cells and NIH 3T3 normal cells revealed that the complexes are toxic only against tumor cells but not to normal cells. In all the biological assays, the complex with copper ion as the metal center showed enhanced activities than the other two.

Nucleic acid binding behaviors and cytotoxic properties of a Ru(II) complex

The interactions of complex [Ru(bpy)(2)(hnip)](2+) (1) {bpy = 2,2'-bipyridine, hnip = 2-(2-hydroxy-1-naphthyl)imidazo[4,5-f][1,10]phenanthroline} with calf thymus DNA and yeast tRNA were investigated by UV-vis spectroscopy, fluorescence spectroscopy, viscosity, equilibrium dialysis, and circular dichroism. In addition, the antitumor activities of complex 1 were evaluated with MTT method. These results indicate that the structures of DNA and RNA have significant effects on the binding behaviors of complex 1. Further, complex 1 demonstrates different antitumor activities against selected cancer cell lines in vitro.

DNA-binding and photocleavage properties of Ru(II) polypyridyl complexes with DNA and their toxicity studies on eukaryotic microorganisms

Four Ru(II) polypyridyl complexes, [Ru(bpy)(2)(7-NO(2)-dppz)](2+), [Ru(bpy)(2)(7-CH(3)-dppz)](2+), [Ru(phen)(2)(7-NO(2)-dppz)](2+), and [Ru(phen)(2)(7-CH(3)-dppz)](2+) (bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline), (7-Nitro-dppz = 7-Nitro dipyrido[3,2-a:2'-3'-c]phenazine, 7-CH(3)-dppz = 7-Methyl dipyrido[3,2-a:2'-3'-c]phenazine), have been synthesized and characterized by IR, UV, elemental analysis, (1)H NMR, (13)C-NMR, and mass spectroscopy. The DNA-binding properties of the four complexes were investigated by spectroscopic and viscosity measurements. The results suggest that all four complexes bind to DNA via an intercalative mode. Under irradiation at 365 nm, all four complexes were found to promote the photocleavage of plasmid pBR 322 DNA. Toxicological effects of the selected complexes were performed on industrially important yeasts (eukaryotic microorganisms).