DNA-binding, catalytic oxidation, CC coupling reactions and antibacterial activities of binuclear Ru(II) thiosemicarbazone complexes: Synthesis and spectral characterization

AbstractNew hexa-coordinated binuclear Ru(II) thiosemicarbazone complexes of the type {[(B)(EPh3)(CO)ClRu]2L} (where, E=P or As; B=PPh3 or AsPh3 or pyridine; L=mononucleating NS donor of N-substituted thiosemicarbazones) have been synthesized and characterized by elemental analysis, FT-IR, UV–vis and 31P{1H} NMR cyclic voltammetric studies. The DNA-binding studies of Ru(II) complexes with calf thymus DNA (CT-DNA) were investigated by UV–vis, viscosity measurements, gel-electrophoresis and fluorescence spectroscopy. The new complexes have been used as catalysts in CC coupling reaction and in the oxidation of alcohols to their corresponding carbonyl compounds by using NMO as co-oxidant and molecular oxygen (O2) atmosphere at ambient temperature. Further, the new binucleating thiosemicarbazone ligands and their Ru(II) complexes were also screened for their antibacterial activity against Klebsiella pneumoniae, Shigella sp., Micrococcus luteus, Escherichia coli and Salmonella typhi. From this study, it was found out that the activity of the complexes almost reaches the effectiveness of the conventional bacteriocide

Synthesis, spectral, dna binding and cleavage properties of ruthenium(II) Schiff base complexes containing PPh3/AsPh3 as co-ligands

A dihydroxybenzaldehyde Schiff base ligands (L1-L3) and its ruthenium(II) complexes, have been synthesized and characterized on the basis of elemental analysis, 1H, 13C, 31P NMR, mass spectra, UV-vis and IR spectra. The binding of ruthenium(II) complexes have been investigated by UV-vis absorption spectroscopy. The experiment reveals that all the compounds can bind to DNA through an electrostatic mode and intrinsic binding constant (Kb) has been estimated under similar set of experimental conditions. Absorption spectral study indicate that the ruthenium(II) complexes has intrinsic binding constant in the range of 1.6-8.6 X 104 M-1. The complex [Ru(CO)(PPh3)2(L3)] bind more strongly than that of the other complexes. In addition, DNA cleavage property were tested for all ruthenium(II) complexes

Synthesis, characterization, DNA binding, DNA cleavage, antioxidant and <i>in vitro</i> cytotoxicity studies of ruthenium(II) complexes containing hydrazone ligands

<p>The synthesis, spectral characterization, and biological studies of ruthenium(II) hydrazone complexes [RuCl(CO)(PPh₃)₂L] (where L = hydrazone ligands) have been carried out. The hydrazones are monobasic bidentate ligands with O and N as the donors and are preferably found in the enol form in all the complexes. The molecular structure of the ligands HL¹, HL²_, and HL³ were determined by single-crystal X-ray diffraction. The DNA binding studies of the ligands and complexes were carried out by absorption spectroscopic and viscosity measurements. The results revealed that the ligands and complexes bind to DNA via intercalation. The DNA cleavage activity of the complexes, evaluated by gel electrophoresis assay, revealed that the complexes are good DNA cleaving agents. The antioxidant properties of the complexes were evaluated against DPPH, OH, and NO radicals, which showed that the complexes have strong radical-scavenging. Further, the <i>in vitro</i> cytotoxic effect of the complexes examined on HeLa and MCF-7 cancer cell lines showed that the complexes exhibited significant anticancer activity.</p