0000000000082380
AUTHOR
Benigno Macías
showing 19 related works from this author
Copper(II) complexes with sulfonamides derived from 2-picolylamine and their use as chemical nucleases
2006
Reaction between 2-picolylamine (2-aminomethylpyridine) with 2-mesitylenesulfonyl and 4- tert -butylbenzene sulfonyl chlorides leads to the formation of 2,4,6-trimethyl- N -[pyridin-2-ilmethyl]benzenesulfonamide (Hpmesa) and 4-ter-butyl- N -[pyridin-2-ilmethyl]benzenesulfonamide (Hptbsa). These compounds react with Cu(II) salts to yield coordination compounds with CuL 2 stoichiometry. The immediate environment of the metal ion is a highly distorted tetrahedron, the sulfonamide ligands acting in a bidentate fashion. Compound Hpmesa crystallizes in monoclinic space group P 2 1 /c (number 14), with Z = 4; complex [Cu(pmesa) 2 ] crystallizes in monoclinic space group P 1 ¯ (number 2), with Z …
Crystal structure of [Cu(N-quinolin-8-yl-p-toluenesulfonamidate)2]: study of its interaction with DNA and hydrogen peroxide
2001
A new copper complex with N-quinolin-8-yl-p-toulenesulfonamide has been prepared and characterised. The compound crystallises in the triclinic system, space group P1, with a=13.457(3), b=15.067(5), c=18.589(3) A; α=112.05(2), β=93.92(2), γ=108.30(2)° and Z=4. The geometry of the Cu(II) ion is distorted square planar. The N-quinolin-8-yl-p-toulenesulfonamidate anion behaves as a bidentate ligand through the N s u l f o n a m i d a t e and N q u i n o l i n e atoms. The complex does not cleave DNA in the presence of hydrogen peroxide.
Mn(II) complexes with sulfonamides as ligands.
2012
Abstract Sulfonamides derived from 8-aminoquinoline react with Mn(II) and Mn(III) salts to form Mn(II) complexes; the Mn(III) species are reduced to the divalent state in the presence of 1,10 phenanthroline and bipyridine. Their molecular structure, determined by single crystal X‐ray diffraction, show that all the complexes present a distorted octahedral geometry, in which the deprotonated sulfonamide acts as a bidentate ligand. UV–visible spectroscopy and changes in the melting temperature (Tm) of calf thymus DNA show a strong interaction of these complexes with DNA. The significant hypochromicity of the charge transfer transition at 370 nm without an appreciable change in wavelength and t…
Copper(II) Polyamine Complexes withN-Benzothiazole Sulfonamides as Counterions — Synthesis, Crystal Structures, and Properties of [Cu(dien)2](L1)2[HL…
2003
Copper(II) complexes of new N-benzothiazole sulfonamides (HL1= N-2-(benzothiazole)naphtalensulfonamide and HL2 = N-2-(6-chlorobenzothiazole)toluenesulfonamide) with ethylenediamine (en) and diethylenetriamine (dien) have been synthesized and characterised. The crystal structures of [Cu(dien)2](L1)2 (1) and [Cu(en)2(H2O)2](L2)2 (2) compounds have been determined. The metal centre adopts a “4+2” distorted octahedral environment in both complexes. Unusually, the sulfonamidate anions act as counterions. Spectroscopic properties are in good agreement with the crystal structures. The superoxide dismutase (SOD)-like activity of complex 2 has been tested. Kupfer(II)-Polyamin-Komplexe mit N-Benzothi…
Structural characterisation and nuclease activity of mixed copper(II) complexes with sulfonamides and bipyridil
2003
Mixed copper complexes have been synthetised through reaction of Cu(II) salts with bipyridil and N-quinolin-8-yl-p-toluenesulfonamide (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.
Synthesis and characterization of sulfonamides containing 8-aminoquinoline and their Ni(II) complexes. Crystalline structures of the Ni complexes
2002
Reaction between 8-aminoquinoline and benzenesulfonyl, toluene-4-sulfonyl and naphthalene-2-sulfonyl chlorides in a basic medium leads to the formation of the corresponding sulfonamides. Reaction of these sulfonamides with Ni(II) salts leads to the formation of the corresponding complexes, with a NiL 2 stoichiometry. Determination of the crystalline structure by X-ray diffraction shows an octahedral environment for the Ni(II) ions, sulfonamides acting as bidentate ligands and two solvent molecules completing the octahedral coordination. The spectroscopic and magnetic properties of these compounds are also discussed.
Crystal structures and spectroscopic properties of copper(II)–bis(2-pyridylcarbonyl)amide–chlorobenzoate complexes
2007
The reaction of 2,4,6-tris(pyridyl)-1,3,5-triazine (ptz) and copper(II) salts in DMF–water (4:1) resulted in the hydrolysis of ptz, giving rise to the bis(2-pyridylcarbonyl)amide anion ( ptO 2 - ) and affording the complexes [Cu(ptO 2 )(2-Clbenz)(H 2 O)] ( 1 ), [Cu(ptO 2 )(3-Clbenz)] ( 2 ), and [Cu(ptO 2 )(4-Clbenz)(DMF)] ( 3 ). This report includes the chemical and spectroscopic characterization of all these compounds along with the crystal structures of the Cu(II) complexes thus formed. The coordination spheres of Cu(II) in 1 and 3 are best described as distorted square based pyramidal, while for 2 the coordination sphere is distorted square planar.
DNA interaction of new copper(II) complexes with sulfonamides as ligands
2007
New copper(II) complexes with sulfonamide ligands have been prepared and characterized. Sulfonamide ligands were prepared through a reaction between 8-aminoquinoline and either 2-mesitylene (Hqmesa), 4-tert-butylbenzene (Hqtbsa), or alpha-toluene (Halphaqtsa) sulfonyl chlorides. The structural analysis carried out for complex [Cu(alphaqtsa)(2)] indicated that the local environment of the Cu(II) cation is between a square planar and a tetrahedral geometry, with stacking of the benzene rings of the sulfonyl ligands between neighbor molecules. Powder EPR spectra at room temperature gave rhombic spectra for the [Cu(alphaqtsa)(2)] and [Cu(qmesa)(2)] complexes and an axial spectrum for the [Cu(qt…
Efficient DNA Cleavage Induced by Copper(II) Complexes of Hydrolysis Derivatives of 2,4,6‐Tri(2‐pyridyl)‐1,3,5‐triazine in the Presence of Reducing A…
2007
The reaction of 2,4,6-tri(pyridyl)-1,3,5-triazine (ptz) and copper(II) salts in dmf/water (1:1) results in the hydrolysis of ptz and formation of the anions bis(2-pyridylcarbonyl)amide (ptO2–) and bis(2-pyridylamine)amide (ptN2–), which are found in the complexes [Cu(ptN2)(OAc)]·3H2O (1), [Cu(ptO2)(OAc)(H2O)]·H2O (2), [Cu(ptN2)(for)]·3H2O (3) (for = formate), [Cu(ptO2)(for)(H2O)] (4), [Cu(ptO2)(benz)]·H2O (5) (benz = benzoate), and [Cu(ptO2)F(H2O)]2·3H2O (6). This report includes the chemical and spectroscopic characterization of all these complexes along with the crystal structures of 4–6. The coordination spheres of CuII in 4 and 5 are best described as distorted tetragonal square pyramid…
Biological Activity of Flavonoids Copper Complexes
2005
Three flavonoid copper(II) complexes Cu2(quercetin)(CH3COO)3(CH3OH) (1), Cu(anthrarufin)(CH3COO)·1/2H2O (2) and Cu(naringin)(OCH3)(CH3OH)2 (3) have been synthesized and characterized by elemental analysis, IR, electronic absorption and EPR (X-band) spectroscopy. The complexes have a strong protective action over the Δsod1 mutant of S. cerevisiae against reactive oxygen radicals generated by an external source of free radicals (H2O2 or the superoxide-generating, menadione). On the other hand, the complexes cleave DNA efficiently even in the absence of reducing agents. The main reactive oxygen species responsible for the DNA strand cleavage have been determined using radical scavengers. A pro…
Nuclease activity of [Cu(sulfathiazolato)2(benzimidazole)2]2MeOH. Synthesis, properties and crystal structure
2002
The [Cu(sulfathiazolato)(2)(benzimidazole)(2)]2MeOH complex has been synthesised and characterised. It crystallises in the monoclinic system, space group C1c1, with unit cell dimensions a=18.829(7) A, b=12.206(3) A, c=17.233(5) A, alpha=90.06(2) degrees, beta=97.28(3) degrees, gamma=90.21(3) degrees and Z=4. The geometry around the copper(II) ion is intermediate between tetrahedral and square planar. The complex produces cleavage of plasmid pUC18 in presence of reducing agents. The efficiency of cleavage reaction of the title compound with pUC18 and with different reducing agents follows the order ascorbate-H(2)O(2)>ascorbate>MPA>dithiothreitol>H(2)O(2).
Complexes of Co(II) and Zn(II) with ofloxacin. Crystal structure of [Co(oflo)2(MeOH)2].4MeOH.
2002
Abstract Ofloxacin (oflo) is able to interact with Co(II) and Zn(II) salts to form complexes with the general formula [M(oflo) 2 ] · 4H 2 O, (M = Co, Zn). Bonding takes place through one of the oxygen atoms of the carboxylate group (acting as a monodentate) and the oxygen atom of the ketonic group. The IR bands of the carboxylic and ketonic group at 1713 and 1622 cm −1 , respectively, shift to 1615 and 1575 cm −1 in the complexes. After dissolution in methanol, complex [Co(oflo) 2 ] · 4H 2 O crystallizes as [Co(oflo) 2 (MeOH) 2 ] · 4MeOH, where Co(II) ion is in an octahedral environment of oxygen atoms. This compound crystallizes in the triclinic system, spatial group P‐1, with unit cell di…
Copper complexes with dithiocarbamates derived from natural occurring amino acids. Crystal and molecular structure of [Cu(en)(EtOH)(H2O)3][Cu(dtc-pro…
2002
Abstract Reaction of Cu(II) salts with dithiocarbamates derived from the amino acids asparagine, glutamine, serine, threonine and tyrosine leads to reduction of the metallic cation and formation of Cu(I) complexes, whereas reaction with proline dithiocarbamate takes place without reduction, leading to formation of a Cu(II) coordination compound. Simultaneous reaction of proline dithiocarbamate and ethylenediamine with Cu(II) leads to the formation of the mixed complex [Cu(en)(EtOH)(H2O)3][Cu(dtc-pro)2]. In the anion, the Cu(II) centre possesses a D2h local symmetry, coordinated by two bidentate dithiocarbamate ligands, while the Cu(II) centre is in a distorted octahedral coordination in the…
Complexes of Ni(II) and Cu(II) with ofloxacin. Crystal structure of a new Cu(II) ofloxacin complex.
2001
Several coordination compounds formed between Ni(II) or Cu(II) with ofloxacin have been synthesised and characterised. According to elemental chemical analysis and FT-IR spectroscopy data, direct reaction of Ni(II) and Cu(II) salts with ofloxacin leads to formation of precipitates for which mass spectrometry demonstrates their polymeric nature. However, crystalline [Cu(oflo)2(H2O)].2H2O is formed if the reaction is carried out in the presence of ammonia. This complex crystallises in the triclinic system, space group P-1 with a=9.2887(12), b=11.2376(14), c=17.874(2) A, alpha=92.12(3), beta=95.39(3), gamma=91.71(3) degrees and Z=2. The local geometry around the Cu(II) ion is a slightly distor…
Oxidative DNA damage of mixed copper(II) complexes with sulfonamides and 1,10-phenanthroline
2003
Abstract 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) 2 (phen)] shows Cu(II) ions are located 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.
Cu(II) complexes with a sulfonamide derived from benzoguanamine. Oxidative cleavage of DNA in the presence of H2O2 and ascorbate
2004
Reaction between benzoguanamine (2,4-diamino-6-phenyl-1,3,5-triazine) and 2-mesitylenesulfonyl chloride leads to formation of a sulfonamide able to form two mononuclear Cu(II) complexes with a CuL(2) stoichiometry. The local environment of the metal cation is a distorted octahedron, with two ligands and two solvent molecules; both complexes crystallize in the monoclinic structure, space group P2(1), with Z=2. In the presence of ascorbate/H(2)O(2,) the two complexes significantly cleavage double-strand pUC18 DNA plasmid. Both complexes exhibit more nuclease efficiency that the copper phenantroline complex. From scavenging reactive oxygen studies we conclude that the hydroxyl radical and a si…
Copper complexes with sulfonamides: crystal structure and interaction with pUC18 plasmid and hydrogen peroxide
2003
N-Quinolin-8-yl-benzenesulfonamide (Hqbsa) and N-quinolin-8-yl-naftalenesulfonamide (Hqnsa) have been synthetized and physicochemically characterized, and used as ligands to coordinate copper complexes with ML2 stoichiometry. The structure of the compounds [Cu(qbsa)2]·DMF and [Cu(qnsa)2] has been determined by X-ray diffraction and both of them crystallize in the orthorhombic system. IR and ESR spectra of the complexes are discussed. The cleavage of pUCI8 by the copper complexes do not behave as chemical nucleases in the range of concentrations assayed.
Toward the development of metal-based synthetic nucleases: DNA binding and oxidative DNA cleavage of a mixed copper(II) complex with N-(9H-purin-6-yl…
2009
Abstract The complex [Cu(N9-ABS)(phen) 2 ]·3.6H 2 O, H 2 N9-ABS = N -(9 H -purin-6-yl)benzenesulfonamide and phen = 1,10-phenanthroline, has been synthesized and then characterized with the aid of X-ray diffraction, analytical, and spectroscopic techniques. The geometry of Cu(II) is distorted square pyramidal with the equatorial positions occupied by three N atoms from two phenantroline molecules and one N atom from the adenine ring of the sulfonamide ligand. The interaction of the complex with DNA was studied by means of viscosity measurements and fluorescence spectroscopy. The results pointed to a classic intercalation of the complex between the DNA base pairs. The complex was found to b…
Copper Complexes with Sulfonamides Derivatives of Natural Amino Acids as Chemical Nucleases
2007
Three new coordination compounds have been prepared by reacting copper salts with sulfonamides derived from amino acids. Their molecular structures have been determined with the aid of single crystal X-ray diffraction. The copper cations are four-coordinated in all cases and the local environment is almost planar. Compound [Cu(ts-gly)(NH3)2]·H2O (1) crystallizes in monoclinic space group P21/c (no 14) with Z = 4 and with unit cell parameters a = 6.0490(12) A, b = 24.719(5) A, c = 9.159(2) A, α = γ = 90°, and β = 94.69(3)°. Compound [Cu(ts-isoleu)(NH3)2] (2) crystallizes in monoclinic space group C2/c (no 8) with Z = 15 and with unit cell parameters a = 30.800(6) A, b = 6.5510(13) A, c = 15.…