Synthesis, Characterization, DNA Binding Properties, Fluorescence Studies and Toxic Activity of Cobalt(III) and Ruthenium(II) Polypyridyl Complexes

Abstract

The new ligand 4-(isopropylbenzaldehyde)imidazo[4,5-f ][1,10]phenanthroline (ippip) and its complexes [Ru(phen)(2)(ippip)](2+)(1),[Co(phen)(2)(ippip)](3+)(2),[Ru(bpy)(2)(ippip)](2+)(3),[Co(bpy)(2)(ippip)](3+)(4)(bpy=2,2-bipyridine) and (phen=1,10-phenanthroline) were synthesized and characterized by ES(+)-MS, (1)H and (13)C NMR. The DNA binding properties of the four complexes were investigated by different spectrophotometric methods and viscosity measurements. The results suggest that complexes bind to calf thymus DNA (CT-DNA) through intercalation. When irradiated at 365 nm, the complexes promote the photocleavage of pBR322 DNA, and complex 1 cleaves DNA more effectively than 2, 3, 4 complexes under comparable experimental conditions. Furthermore, photocleavage studies reveal that singlet oxygen ((1)O(2)) plays a significant role in the photocleavage.

Combined Systems Approaches Reveal a Multistage Mode of Action of a Marine Antimicrobial Peptide against Pathogenic Escherichia coli and Its Protective Effect against Bacterial Peritonitis and Endotoxemia

“…CD spectrum analysis is an extraordinarily sensitive and useful technique to monitor changes in DNA morphology during drug-DNA interactions (25). The DNA-binding affinity of N4 was further assessed using a CD spectrometer.…”

Cobalt derivatives as promising therapeutic agents

“…In addition to these strategies, the flexible cobalt platform can be enhanced with further levels of control. For example, the low-energy d-d transitions and MLCT bands of cobalt complexes allows for the incorporation of radiation-[38,46,47] or photo-responsive elements [56–60]. Complexes that respond to such exogenous energy sources will permit spatial and temporal control of therapeutic activity.…”

Synthesis, Characterisation, Interaction with DNA, Cytotoxicity, and Apoptotic Studies of Ruthenium(II) Polypyridyl Complexes

“…Based on the binding data and the viscosity experiment we conclude that these complexes bind to DNA by intercalation, but they do not intercalate as strongly as proven intercalators like ethidium bromide, [29] or analogous Ru II complexes containing bidentate polycyclic heteroaromatic ligands. [9][10][11] …”

“…Recently, the effects of some bidentate ancillary ligands such as bipyridine (bpy), 1,10-phenanthroline (phen), dimethyl bipyridine (dmb), and diphenyl bipyridine (dip) have been investigated by many research groups, including ours. [9][10][11] Studies on the biological activity of these complexes have been paid great attention. [12][13][14] However, there are only a few reports on ruthenium(II) complexes with monodentate ancillary ligands.…”