title: Mixed-valence Cu(II)/Cu(I) complex of quinolone ciprofloxacin isolated by a hydrothermal reaction in the presence of L-histidine: comparison of biological activities of various copper-ciprofloxacin compounds.
abstract: A new quinolone-metal complex was prepared by a hydrothermal reaction in the presence of L-histidine that served as a reducing agent for a metal. The title compound [Cu(II)(cfH)(2)(Cu(I)Cl(2))(2)] (1) is a mixed-valence Cu(II)-Cu(I) complex, which contains two ciprofloxacin (cfH) molecules bonded to the central copper(II) atom and two almost planar [Cu(I)Cl(2)](-) moieties. Both metal centers are connected through two bridging atoms (chloride and quinolone oxygen). The electrochemical methods (differential-pulse polarography and cyclovoltammetric measurements) confirmed the presence of various copper-ciprofloxacin complex species in aqueous solution at low concentrations used in biological activity tests and also indicated that the equilibria in this system are very complex. The biological properties of the title compound and some previously isolated copper-ciprofloxacin complexes ([Cu(cfH)(2)Cl(2)].6H(2)O (2) and [CuCl(cfH)(phen)]Cl.2H(2)O (3)) (phen=1, 10-phenantroline) were determined and compared. The DNA gyrase inhibition tests and antibacterial activity tests have shown that the effect of copper complexes is comparable to that of free quinolone. Additionally, an interesting DNA cleavage activity of the title compound was also discovered.
authors.affiliation: Faculty of Chemistry and Chemical Technology, University of Ljubljana, Askerceva 5, SI-1000 Ljubljana, Slovenia.
authors.forename: Petra
authors.initials: P
authors.lastname: Drevensek
authors.forename: Tatjana
authors.initials: T
authors.lastname: Zupancic
authors.forename: Boris
authors.initials: B
authors.lastname: Pihlar
authors.forename: Roman
authors.initials: R
authors.lastname: Jerala
authors.forename: Uwe
authors.initials: U
authors.lastname: Kolitsch
authors.forename: Andreja
authors.initials: A
authors.lastname: Plaper
authors.forename: Iztok
authors.initials: I
authors.lastname: Turel
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D002939:Ciprofloxacin / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D003300:Copper / Q000737:chemistry; D018360:Crystallography, X-Ray; D004278:DNA, Superhelical / Q000187:drug effects; D004563:Electrochemistry; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D006639:Histidine; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D011048:Polarography; D017550:Spectroscopy, Fourier Transform Infrared; D059005:Topoisomerase II Inhibitors
chemical_list: D000900:Anti-Bacterial Agents; D004278:DNA, Superhelical; D004791:Enzyme Inhibitors; D009942:Organometallic Compounds; D059005:Topoisomerase II Inhibitors; D006639:Histidine; D002939:Ciprofloxacin; D003300:Copper