title: DNA cleavage reaction induced by dimeric copper(II) complexes of N-substituted thiazole sulfonamides.
abstract: A new dinuclear copper(II) complex has been synthesised and structurally characterised: [Cu2(tz-ben)4] (Htz-ben = N-thiazol-2-yl-benzenesulfonamide). Its crystal structure, magnetic properties and electronic paramagnetic resonance (EPR) spectra were studied in detail. In the compound the metal centres are bridged by four non-linear triatomic NCN groups. The coordination geometry of the copper ions in the dinuclear entity is distorted square pyramidal (4+1). Two thiazole N and two sulfonamido N atoms occupy the equatorial positions and one sulfonamido O atom is in the axial position. Magnetic susceptibility data show a strong antiferromagnetic coupling, -2J = 114.1 cm(-1). The EPR spectra of a polycrystalline sample of compound has been obtained at the X- and Q-band frequencies at different temperatures. Above 20K the spectra are characteristic of S = 1 species with a zero field splitting parameter D = 0.4 cm(-1). The EPR parameters are discussed in terms of the known binuclear structures. The chemical nuclease ability of the title complex and that of the related [Cu2(tz-tol)4] compound (Htz-tol = N-thiazol-2-yl-toluenesulfonamide) is reported. The participation of hydroxyl radicals and a singlet oxygen-like entity in the DNA cleavage reaction has been deduced from the assays with radical oxygen scavengers.
authors.affiliation: Departament de Química Inorgànica, Universitat de València, Avda. Vicent Estellés s/n, 46100-Burjassot, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Cejudo
authors.forename: G
authors.initials: G
authors.lastname: Alzuet
authors.forename: M
authors.initials: M
authors.lastname: González-Alvarez
authors.forename: J L
authors.initials: JL
authors.lastname: García-Gimenez
authors.forename: J
authors.initials: J
authors.lastname: Borrás
authors.forename: M
authors.initials: M
authors.lastname: Liu-González
mesh_terms: D003300:Copper / Q000737:chemistry / Q000494:pharmacology*; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D013058:Mass Spectrometry; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D013055:Spectrophotometry, Infrared; D013449:Sulfonamides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D013844:Thiazoles / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D000096926:Benzenesulfonamides
chemical_list: D003300:Copper; D004247:DNA; D009942:Organometallic Compounds; D013449:Sulfonamides; D013844:Thiazoles; C509396:N-thiazol-2-yl-benzenesulfonamide Cu(II); D000096926:Benzenesulfonamides