title: Methyl-substituted 4-nitropyridine N-oxides as ligands: structural, spectroscopic, magnetic and cytotoxic characteristics of copper(II) complexes.
abstract: Seven new mono- and dinuclear Cu(II) complexes containing various methyl substituted 4-nitropyridine N-oxides as ligands were isolated and characterized physicochemically and biologically. The characterization included elemental analysis, magnetic and spectroscopic methods (diffuse reflectance and UV-visible absorption, IR, FIR). A single crystal X-ray diffraction analysis was performed for the complex with 2,5-dimethyl-4-nitropyridine N-oxide. Trans- and cis-square planar configuration around Cu ion was established for mono- and dinuclear species, respectively. In methanolic solutions the dinuclear species decompose into mononuclear ones with increasing 4-->6 coordination number with attachment of two solvent molecules. The IR spectra showed that the strength of the Cu-ligand bond gauged by the degree of N-O elongation changed irregularly with position and number of methyl groups. Cytotoxic studies on the MCF-7 human breast cancer line revealed a structure-activity relationship: double blocking of the NO(2) group with two CH(3) groups rendered the complex completely inactive.
authors.affiliation: Department of Bioorganic Chemistry, Faculty of Industry and Economics, Academy of Economics, 53-345 Wrocław, Poland. apuszko@credit.ae.wroc.pl
authors.forename: Aniela
authors.initials: A
authors.lastname: Puszko
authors.forename: Lucyna
authors.initials: L
authors.lastname: Wasylina
authors.forename: Marzena
authors.initials: M
authors.lastname: Pełczynska
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Staszak
authors.forename: Anna
authors.initials: A
authors.lastname: Adach
authors.forename: Maria
authors.initials: M
authors.lastname: Cieślak-Golonka
authors.forename: Maria
authors.initials: M
authors.lastname: Kubiak
mesh_terms: D015112:4-Nitroquinoline-1-oxide / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D003300:Copper / Q000737:chemistry*; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D008024:Ligands; D008280:Magnetics; D008958:Models, Molecular; D013057:Spectrum Analysis / Q000379:methods
chemical_list: D008024:Ligands; D015112:4-Nitroquinoline-1-oxide; D003300:Copper