22393-36-8Relevant articles and documents
DNA binding properties and antibacterial activity of heterolyptic transition metal complexes with 2,2-bipyridyl and 2-acetylthiophene thiosemicarbazone
Srinivasulu, Kummara,Reddy, Katreddi Hussain,Anuja,Dhanalakshmi,Ramesh, Golla
, p. 1905 - 1912 (2019/08/08)
Metal complexes having the composition M(Bipy)Cl2 (where, M = Cu(II), Ni(II) and Co(II); Bipy = 2,2-bipyridyl) are reacted with 2-acetylthiophene thiosemicarbazone (ATT) to produce heteroleptic transition metal complexes with molecular formula [M(Bipy)ATT]. The complexes are characterized by mass spectra, molar conductivity, infrared and electronic spectra. Electrochemical behaviour of these metal complexes was investigated by cyclic voltammetric studies. The metal complexes show quasi reversible cyclic voltammetric responses for the Cu(II)/Cu(I) couple. The binding properties of these complexes with calf-thymus DNA have been investigated by using absorption spectrophotometry. Metal complexes are screened for their antibacterial activity by using agar well diffusion method against pathogenic bacterial strains viz. Escherichia coli and Staphylococcus aureus. Antibacterial activity of the present complexes are comparable with the activity of ciprofloxacin. The Cu(Bipy)Cl2 complex inhibits bacteria more strongly than any other complex. The Ni(Bipy)ATT complex shows more activity than the parent complex, Ni(Bipy)Cl2.
Fluorescence and electron paramagnetic resonance studies of norfloxacin and N-donor mixed-ligand ternary copper(II) complexes: Stability and interaction with SDS micelles
Vignoli Muniz, Gabriel S.,Incio, Jimmy Llontop,Alves, Odivaldo C.,Krambrock, Klaus,Teixeira, Letícia R.,Louro, Sonia R.W.
, p. 133 - 138 (2017/08/29)
The stability of ternary copper(II) complexes of a heterocyclic ligand, L (L being 2,2′-bipyridine (bipy) or 1,10-phenanthroline (phen)) and the fluorescent antibacterial agent norfloxacin (NFX) as the second ligand was studied at pH 7.4 and different ionic strengths. Fluorescence quenching upon titration of NFX with the binary complexes allowed to obtain stability constants for NFX binding, Kb, as a function of ionic strength. The Kb values vary by more than two orders of magnitude when buffer concentration varies from 0.5 to 100 mM. It was observed that previously synthesized ternary complexes dissociate in buffer according with the obtained stability constants. This shows that equimolar solutions of NFX and binary complexes are equivalent to solutions of synthesized ternary complexes. The interaction of the ternary copper complexes with anionic SDS (sodium dodecyl sulfate) micelles was studied by fluorescence and electron paramagnetic resonance (EPR). Titration of NFX-loaded SDS micelles with the complexes Cu:L allowed to determine the stability constants inside the micelles. Fluorescence quenching demonstrated that SDS micelles increase the stability constants by factors around 50. EPR spectra gave details of the copper(II) local environment, and demonstrated that the structure of the ternary complexes inside SDS micelles is different from that in buffer. Mononuclear ternary complexes formed inside the micelles, while in buffer most ternary complexes are binuclear. The results show that anionic membrane interfaces increase formation of copper fluoroquinolone complexes, which can influence bioavailability, membrane diffusion, and mechanism of action of the antibiotics.
Synthesis and structural characterization of ternary Cu (II) complexes of glycine with 2,2′-bipyridine and 2,2′-dipyridylamine. the DNA-binding studies and biological activity
Mohamed, Mervat S.,Shoukry, Azza A.,Ali, Ayat G.
, p. 562 - 570 (2012/01/15)
In this study two new complexes [Cu(bpy)(Gly)Cl]·2H2O (1) and [Cu(dpa)(Gly)Cl]·2H2O (2) (bpy = 2,2′-bipyridine; dpa = 2,2′-dipyridylamine, Gly = glycine) have been synthesized and characterized by elemental analysis, IR, TGA, UV-vis and magnetic susceptibility measurements. The binding properties of the complexes with CT-DNA were investigated by electronic absorption spectra. The intrinsic binding constants (Kb) calculated from UV-vis absorption studies were 1.84 × 103 M-1 and 3.1 × 103 M-1 for complexes 1 and 2 respectively. Thermal denaturation has been systematically studied by spectrophotometric method and the calculated ΔTm was nearly 5 °C for each complex. All the results suggest that the interaction modes between the complexes and CT-DNA were electrostatic and/or groove binding. The redox behavior of the two complexes was investigated by cyclic voltammetry. Both complexes, in presence and absence of CT-DNA show a quasi-reversible wave corresponding to CuII/CuI redox couple. The change in E1/2, ΔE and Ipc/Ipa ascertain the interaction of complexes 1 and 2 with CT-DNA. Further insight into the binding of complexes with CT-DNA has been made by gel electrophoresis, where the binding of complexes is confirmed through decreasing the mobility and intensity of DNA bands. In addition, the antitumor activity of the complexes was tested on two cancer cell lines; the breast cancer (MCF7) and the human hepatocellular carcinoma (HEPG2), as well as one normal cell line; the human normal melanocytes (HFB4). The results showed that complex 1 was more potent antitumor agent than complex 2. The in-vitro antimicrobial activity of the two complexes was carried out using the disc diffusion method against different species of pathogenic bacteria and fungi. The activity data showed that complex 2 was more active in inhibiting the growth of the tested organisms.
