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 the minor changes in the relative viscosity of calf thymus DNA have been attributed to an interaction between the surface of DNA and the complexes. [Mn(qbsa)(2)(MeOH)(2)], [Mn(qbsa)(2)(phen)], [Mn(qtsa)(2)(H(2)O)(2)] and [Mn(qtsa)(2)(phen)] (where qbsa=N-quinolin-8-yl-bencenesulfonamide, qtsa=N-quinolin-8-yl-p-toluenesulfonamide and qnsa=N-quinolin-8-yl-naftalenesulfonamide) exhibit a prominent nuclease activity and the mechanism of DNA cleavage is investigated.
Subject(s)
DNA/chemistry , Deoxyribonucleases/chemistry , Deoxyribonucleases/chemical synthesis , Manganese/chemistry , Plasmids/chemistry , Sulfonamides/chemistry , Animals , Cattle , Molecular StructureABSTRACT
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(qtbsa)(2)] complex, probably due to the steric hindrance of the methyl groups. Complexes [Cu(alphaqtsa)(2)] and [Cu(qmesa)(2)] are artificial chemical nucleases that degrade DNA in the presence of sodium ascorbate. A study of the radical scavengers revealed that the ROS (reactive oxygen species) involved in the DNA damage were hydroxyl, singlet oxygen-like species, and superoxide anion.
Subject(s)
Copper/chemistry , DNA/chemistry , Intercalating Agents/chemistry , Organometallic Compounds/chemistry , Sulfonamides/chemistry , Ascorbic Acid/chemistry , Copper/pharmacology , Crystallography, X-Ray , DNA/drug effects , Intercalating Agents/chemical synthesis , Molecular Conformation , Molecular Structure , Organometallic Compounds/chemical synthesis , Plasmids/drug effects , Reactive Oxygen Species/chemistry , Sulfonamides/chemical synthesisABSTRACT
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.
Subject(s)
Copper/chemistry , DNA Damage , Organometallic Compounds/chemical synthesis , Crystallization , Hydrolysis/drug effects , Molecular Structure , Organometallic Compounds/chemistry , Organometallic Compounds/pharmacology , Oxidation-Reduction , Phenanthrolines/chemical synthesis , Phenanthrolines/chemistry , Phenanthrolines/pharmacology , Plasmids/drug effects , Plasmids/metabolism , Reactive Oxygen Species/chemistry , Reactive Oxygen Species/metabolism , Sulfonamides/chemical synthesis , Sulfonamides/chemistry , Sulfonamides/pharmacology , Superoxide Dismutase/metabolismABSTRACT
Objetivos: presentar los resultados de las cirugías de revascularización coronaria sin bomba realizadas en la Clínica Cardiovascular Santa María, durante el período de enero de 1994 a agosto de 2002. Materiales y métodos: se presenta un grupo de pacientes a quienes se les realizó revascularización miocárdica sin bomba. Los datos fueron obtenidos de la base de datos de la Institución (SICI), y manejados en el paquete estadístico SPSS 10.0. Se realizaron pruebas de Chi2 o prueba exacta de Fisher cuando fue necesario para variables discontinuas y se utilizó la t de student para la comparación de variables continuas. Los datos son presentados en porcentaje para los valores totales y promedio ñ desviación típica para las variables continuas. Se tomaron valores de p < 0.05 como los que tenían correlación estadísticamente significativa, con intervalos de confianza de 95 por ciento. Resultados: se presentan 320 pacientes a quienes se les realizó revascularización miocárdica sin bomba durante el período comprendido entre enero de 1994 a agosto de 2002, que corresponden a 14 por ciento de las cirugías de revascularización coronaria realizadas en la Institución durante este período. 71 por ciento fueron de sexo masculino con un promedio de edad de 60.4 ñ 9.9 años. La hipertensión arterial y la dislipidemia fueron los factores de riesgo más frecuentemente asociados. 72 por ciento presentaron enfermedad de 3 vasos y 17 por ciento tenían enfermedad de tronco izquierdo. El promedio de injertos fue de 2.98 ñ 0.92 por paciente. 35 por ciento de los pacientes presentaron algún tipo de complicación y la mortalidad global fue de 3.8 por ciento, mientras que ajustada por riesgo fue de 2.85 ñ 2.95 por ciento
Subject(s)
Cardiovascular Surgical Procedures/instrumentation , Cardiovascular Surgical Procedures/methods , Myocardial Revascularization/methods , Myocardial RevascularizationABSTRACT
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 dimensions a = 9.3670(12), b = 11.4135(17), c = 11.851(2) A y alpha = 71.999(14), beta = 73.698(12), gamma = 83.528(14) degrees. Magnetic properties (effective magnetic moment 5.02 BM) and visible spectrum (bands at 490, 510, and 1152 nm) are characteristic of such an octahedral geometry. (1)H- and (13)C-NMR spectra of the Zn(II) complex indicate only small structural changes in ofloxacin upon coordination to the metallic site.
Subject(s)
Cobalt/chemistry , Ofloxacin/chemistry , Zinc/chemistry , Chemistry, Pharmaceutical , Crystallization , Crystallography, X-Ray/methodsABSTRACT
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; alpha=112.05(2), beta=93.92(2), gamma=108.30(2) degrees 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(sulfonamidate)and N(quinoline) atoms. The complex does not cleave DNA in the presence of hydrogen peroxide.
