DNA interaction of new copper(II) complexes with sulfonamides as ligands (original) (raw)
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Oxidative DNA damage of mixed copper(II) complexes with sulfonamides and 1,10-phenanthroline
Journal of Inorganic Biochemistry, 2003
Mixed coordination compounds of Cu(II) with sulfonamides and 1,10-phenanthroline as ligands have been prepared and characterised. Single crystal structural determination of the complex [Cu(N-quinolin-8-yl-p-toluenesulfonamidate) (phen)] shows Cu(II) ions are located 2 in a highly distorted octahedral environment, probably as a consequence of the Jahn-Teller effect. The FT-IR and electronic paramagnetic resonance (EPR) spectra are also discussed. The mixed complexes prepared undergo an extensive DNA cleavage in the presence of ascorbate and hydrogen peroxide. Two of the complexes have higher nucleolytic efficiency than the bis(o-phenanthroline)copper(II) complex.
Polyhedron, 2009
Ternary copper(II) complexes (1-3) of 1,10-phenanthroline and ethylenediamine-R-sulfonamide derivatives (R = benzene, toluene and naphthalene rings) have been synthesized and characterized with the aid of X-ray diffraction and spectroscopic and electrochemical techniques. The crystal structures of the complexes show that the coordination polyhedron around copper(II) is distorted square planar. Both 1,10phenanthroline and ethylenediamine-R-sulfonamide act as bidentate ligands. The three structures are stabilized by p-p stacking interactions. The interaction of the complexes with calf thymus DNA has been investigated by thermal denaturation studies which indicated that DNA was stabilized in the presence of the compounds. The increase in DNA stability induced by the complexes follows the order: 3 > 2 > 1. All three complexes were found to be very efficient agents of plasmid DNA cleavage in the presence of ascorbate as reducing agent. Mechanistic studies of the DNA cleavage process performed with radical scavengers show that the reactive oxygen species involved in the DNA damage are the hydroxyl radical, singlet oxygen-like species, the superoxide * and hydrogen peroxide.
Synthesis, characterization, DNA binding, cleavage activity and cytotoxicity of copper(ii) complexes
Dalton Transactions, 2014
Three new mononuclear copper(II) complexes, [Cu(L 2 )] 2+ (1), [Cu(acac)(L)] + (2), and [Cu(acac-Cl)(L)] + (3) (L = 2-(4-pyridine)oxazo[4,5-f ]1,10-phenanthroline (4-PDOP); acac = acetylacetone; acac-Cl = 3-chloroacetylacetone), have been synthesized and characterized by elemental analysis, high resolution mass spectrometry (Q-TOF), and IR spectroscopy. Two of the complexes were structurally characterized by single-crystal X-ray diffraction techniques. Their interactions with DNA were studied by UV-vis absorption and emission spectra, viscosity, thermal melting, DNA unwinding assay and CD spectroscopy. The nucleolytic cleavage activity of the compounds was carried out on double stranded pBR322 circular plasmid DNA by using a gel electrophoresis experiment in the presence and absence of an oxidant (H 2 O 2 ). Active oxygen intermediates such as hydroxyl radicals and hydrogen peroxide generated in the presence of L and complexes 1-3 may act as active species for the DNA scission. The cytotoxicity of the complexes against HepG2 cancer cells was also studied. † Electronic supplementary information (ESI) available. CCDC 930714 and 930715. For ESI and crystallographic data in CIF or other electronic format see
Journal of Inorganic Biochemistry, 2013
Ternary copper(II) complexes [Cu(NST) 2 (phen)] (1) and [Cu(NST) 2 (NH 3) 2 ]•H 2 O (2) [HNST = N-(4,5dimethylthiazol-2-yl)naphthalene-1-sulfonamide] were prepared and characterized by physico-chemical techniques. Both 1 and 2 were structurally characterized by X-ray crystallography. The crystal structures show the presence of a distorted square planar CuN 4 geometry in which the deprotonated sulfonamide, acting as monodentate ligand, binds to the metal ion through the thiazole N atom. Both complexes present intermolecular π-π stacking interactions between phenanthroline rings (compound 1) and between naphthalene rings (compound 2). The interaction of the complexes with CT DNA was studied by means of thermal denaturation, viscosity measurements and fluorescence spectroscopy. The complexes display good binding propensity to the calf thymus DNA giving the order: 1>2. Complex 1, which has a higher capability for binding to DNA, showed better nuclease activity than 2 in the presence of ascorbate/H 2 O 2. Both the kinetics and the mechanism of the DNA cleavage reaction were investigated. Furthermore, complex 1 showed efficient photo-induced DNA cleavage activity on irradiation with UV light in the absence of any external reagent. The UV light induced DNA cleavage follows a photo-redox pathway with generation of hydroxyl radicals as reactive species. In addition, the cytotoxic properties of both complexes (1 and 2) were evaluated in human cancer cells (HeLa, Caco-2 and MDA-468). The low IC 50 values, in particular those against Caco-2, have indicated that the compounds can be considered as promising chemotherapeutic agents.
DNA interactions of mixed ligand copper(II) complexes with sulphur containing ligands
Indian Journal of Chemistry Section a
Mixed ligand copper (II) complexes having the composition [Cu(tsc)Cl 2 ](I), [Cu(tsc) 2 Cl 2 ](II), [Cu(phen)Cl 2 ](III), [Cu(dmso) 2 Cl 2 ](IV), [Cu(phen)(tsc)Cl 2 ](V) and [Cu(dmso) 2 (tsc)Cl 2 ](VI) (where tsc = thiosemicarbazide, phen = ortho phenanthroline and dmso = dimethyl sulphoxide) have been synthesized and characterized on the basis of elemental analyses, conductivity measurements, magnetic susceptibility data, electronic, IR and ESR spectroscopy. Electrochemical behaviour of these complexes has been investigated by cyclic voltammetry. All complexes undergo quasi-reversible oneelectron electrochemical reduction (Cu II /Cu I) in the potential range 0.17-0.36 V against Ag/AgCl reference electrode. The E 1/2 values of mixed ligand complexes are less than the parent complexes, presumably due to the increase in ligand number and size of the complex. The binding studies of copper complexes with CT-DNA have been investigated using absorption spectrophotometry.
DNA Binding, DNA Cleavage, and Cytotoxicity Studies of Two New Copper (II) Complexes
DNA and Cell Biology, 2011
The DNA binding behavior of [Cu(phen)(phen-dione)Cl]Cl (1) and [Cu(bpy)(phen-dione)Cl]Cl (2) was studied with a series of techniques including UV-vis absorption, circular dichroism spectroscopy, and viscometric methods. Cytotoxicity effect and DNA unwinding properties were also investigated. The results indicate that the Cu(II) complexes interact with calf-thymus DNA by both partially intercalative and hydrogen binding. These findings have been further substantiated by the determination of intrinsic binding constants spectrophotometrically, 12.5Â10 5 and 5Â10 5 for 1 and 2, respectively. Our findings suggest that the type of ligands and structure of complexes have marked effect on the binding affinity of complexes involving CT-DNA. Circular dichroism results show that complex 1 causes considerable increase in base stacking of DNA, whereas 2 decreases the base stacking, which is related to more extended aromatic area of 1,10-phenanthroline in 1 rather than bipyridine in 2. Slow decrease in DNA viscosity indicates partially intercalative binding in addition to hydrogen binding on the surface of DNA. The second binding mode was also confirmed by additional tests: interaction in denaturation condition and acidic pH. Also, these new complexes induced cleavage in pUC18 plasmid DNA as indicated in gel electrophoresis and showed excellent antitumor activity against K562 (human chronic myeloid leukemia) cells.
Polyhedron, 2007
Mixed ligand complexes having the formulae Cu(RPO) 2 Py 2 , Cu(RPO) 2 Im 2 and Cu(DBO) 2 Py 2 [RPO = resacetophenone oxime, DBO = 2,4-dihydroxybenzophenone oxime, Py = pyridine and Im = imidazole] have been synthesized and characterized by UV-Vis, IR, ESR, cyclic voltammetry and magnetic susceptibility methods. Absorption studies revealed that each of these octahedral complexes is an avid binder of calf thymus DNA. The apparent binding constants for mixed ligand complexes are in order of 10 4 -10 5 M À1 . Based on the data obtained in the DNA binding studies a partial intercalative mode of binding is suggested for these complexes. The nucleolytic cleavage activity of the adducts was carried out on double stranded pBR322 circular plasmid DNA by using a gel electrophoresis experiment in the presence and absence of oxidant (H 2 O 2 ). All the metal complexes cleaved supercoiled DNA by hydrolytic and oxidative paths. The oxidative path dominates the hydrolytic cleavage. The hydrolytic cleavage of DNA is evidenced from the control experiments showing discernable cleavage inhibition in the presence of the hydroxyl radical inhibitor DMSO or the singlet oxygen quencher azide ion.
Inorganica Chimica Acta, 2003
Mixed copper complexes have been synthetised through reaction of Cu(II) salts with bipyridil and N -quinolin-8-yl-ptoluenesulfonamide (Hqtsa), N -quinolin-8-yl-benzenesulfonamide (Hqbsa) or N -quinolin-8-yl-naftalenesulfonamide (Hqnsa). Single crystal X-ray diffraction structure determination shows that copper cations are five-coordinated, one complex have distorted bipyramidal trigonal geometry and the other have a distorted square-pyramid. The FT IR and EPR spectra are also reported. Electrophoresis results show that the synthetised complexes in the presence of ascorbate and hydrogen peroxide are chemical nucleases. #
Spectrochimica Acta Part A-molecular and Biomolecular Spectroscopy
The DNA binding behavior of [Cu(phen)(phen-dione)Cl]Cl (1) and [Cu(bpy)(phen-dione)Cl]Cl (2) was studied with a series of techniques including UV-vis absorption, circular dichroism spectroscopy, and viscometric methods. Cytotoxicity effect and DNA unwinding properties were also investigated. The results indicate that the Cu(II) complexes interact with calf-thymus DNA by both partially intercalative and hydrogen binding. These have been further substantiated by the determination of intrinsic binding constants spectrophotometrically, 12.5Â10 5 and 5Â10 5 for 1 and 2, respectively. Our findings suggest that the type of ligands and structure of complexes have marked effect on the binding affinity of complexes involving CT-DNA. Circular dichroism results show that complex 1 causes considerable increase in base stacking of DNA, whereas 2 decreases the base stacking, which is related to more extended aromatic area of 1,10-phenanthroline in 1 rather than bipyridine in 2. Slow decrease in DNA viscosity indicates partially intercalative binding besides hydrogen binding on DNA surface. The second binding mode was also confirmed by additional tests: interaction in denaturation condition and acidic pH. Also, these new complexes induced cleavage in pUC18 plasmid DNA as indicated in gel electrophoresis and showed excellent antitumor activity against K562 (human chronic myeloid leukemia) cells.