DNA interaction, anticancer, cytotoxicity and genotoxicity studies with potential pyrazine-bipyrazole dinuclear µ-oxo bridged Au(III) complexes.

Pyrazine-bipyrazole-based µ-oxo bridged dinuclear Au(III) complexes were synthesized and characterized by various spectrometric (1H-NMR, 13C (APT) NMR, FT-IR, Mass spectrometry) and analytical techniques (elemental analysis and conductance measurement). The evaluation of DNA binding activity by UV-Vis absorption spectra and viscosity measurement demonstrated that all the compounds intercalate in between the stacks of DNA base pair and the binding constant values were observed in the range of 5.4 × 104-2.17 × 105 M-1. The molecular docking study also supports the intercalation mode of binding. The anti-proliferation activity of complexes on A549 (Lung adenocarcinoma) cells by MTT assay demonstrated IC50 values in the range of 47.46 -298.12 µg/mL. The genotoxicity of compounds was checked by smearing observed in the DNA of S. pombe cell under the influence of complexes. The in vivo cytotoxicity of compounds against brine shrimp demonstrated the LC50 values in the range of 4.59-27.22 µg/mL. The promising results of the Au(III) complexes received significant attention and make them suitable for the new metallodrugs after the detailed mechanistic biological study.

DNA Interaction, in vitro Antibacterial and Cytotoxic Activities of Ru(III) Heterochelates.

Ruthenium(III) complexes [Ru(bphtpy)(PPh3)Cl3] (bphfpy = diphenylfuranylpyridine derivatives) were synthesized and characterized by LCMS, IR spectroscopy, elemental analysis and magnetic measurements. All the complexes were screened for their antibacterial activity in terms of minimum inhibitory concentration against two Gram-positive and three Gram-negative bacterial species. DNA binding study by absorption titration and viscosity measurement shows that complexes bind in an intercalating mode, which is also confirmed by molecular docking. All the complexes were also screened for the DNA nuclease property of pUC19 plasmid DNA. The cytotoxicity study of the synthesized complexes was performed to elucidate the LC50 values to find out the toxicity profile of the complexes.

Biological Significance of Hetero-Scaffolds Based Gold(III) Complexes.

Synthesized ligands and complexes, [Au(Ln)Cl2]Cl, have been characterized by various techniques such as elemental analysis, LC-MS, FT-IR, UV-Vis, 1H and 13C NMR spectroscopy, conductance measurement and magnetic moments measurement. The experimental results show that complexes exhibit higher antibacterial activity against Gram(+ve) and Gram(-ve) microorganisms than free ligands. The in vitro cytotoxicity and cellular level cytotoxicity suggest that Au(III) complexes show better activity than corresponding ligands. The DNA interaction study has been evaluated using absorption titration. The experimental evidence indicates (Kb = 1.08-3.44 • 105 M-1) that all the complexes have been bind to HS-DNA by intercalation mode. To further verify the nature of interaction viscosity measurement and molecular modeling have been carried out which suggest the intercalation binding between complex and DNA. The Schizosaccharomyces pombe cell DNA cleavage has been performed using agarose gel and their photographic images of complexes show smearing of DNA due to DNA cleavage from the nucleus.