title: Synthesis, structural characterization, cytotoxic properties and DNA binding of a dinuclear copper(II) complex.
abstract: In this study a novel dinuclear copper(II) complex with adenine and phenanthroline has been synthesized and its structure determined by single crystal X-ray diffraction. In the dinuclear complex [Cu₂(μ-adenine)₂(phen)₂(H2O)2](NO3)4·0.5H2O (phen=1,10-phenanthroline) (1) the two Cu(II) centres exhibit a distorted square pyramidal coordination geometry linked by two nitrogen donors from adenine bridges leading to a Cu-Cu distance of 3.242(3)Å. Intramolecular and intermolecular π⋯π interactions as well as an H-bonding network were observed. The antitumor capacity of the complex has been tested in vitro against human cancer cell lines, cervical carcinoma (HeLa) and colorectal adenocarcinoma (Caco-2), by metabolic tests, using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide as reagent. The complex 1 has remarkable low IC50 values of 0.87±0.06μM (HeLa) and 0.44±0.06μM (Caco-2), when compared with values for cisplatin against the same cell lines. The interaction of complex 1 with calf thymus DNA (CT DNA) was further investigated by absorption and fluorescence spectroscopic methods. A binding constant of 5.09×10(5)M(-1) was obtained from UV-vis absorption studies.
authors.affiliation: Departamento de Química, CICECO, Universidade de Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: B J M Leite
authors.initials: BJ
authors.lastname: Ferreira
authors.affiliation: Departamento de Química, CICECO, Universidade de Aveiro, 3810-193 Aveiro, Portugal. Electronic address: pbrandao@ua.pt.
authors.forename: P
authors.initials: P
authors.lastname: Brandão
authors.affiliation: Departamento de Química e Bioquímica, Centro de Química e Bioquímica, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
authors.forename: M
authors.initials: M
authors.lastname: Meireles
authors.affiliation: Departamento de Bioquímica, Faculdade de Medicina do Porto e I3S, Universidade do Porto, 4200-319 Porto, Portugal.
authors.forename: Fátima
authors.initials: F
authors.lastname: Martel
authors.affiliation: Departamento de Bioquímica, Faculdade de Medicina do Porto e I3S, Universidade do Porto, 4200-319 Porto, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Correia-Branco
authors.affiliation: Departamento de Química e Bioquímica, REQUIMTE/LAQV, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal.
authors.forename: Diana M
authors.initials: DM
authors.lastname: Fernandes
authors.affiliation: Departamento de Química, CICECO, Universidade de Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: T M
authors.initials: TM
authors.lastname: Santos
authors.affiliation: Departamento de Química, CICECO, Universidade de Aveiro, 3810-193 Aveiro, Portugal; Departamento de Química, IBIMED and CICECO, Universidade de Aveiro, 3810-193 Aveiro, Portugal. Electronic address: vitor.felix@ua.pt.
authors.forename: V
authors.initials: V
authors.lastname: Félix
mesh_terms: D000225:Adenine; D003300:Copper / Q000737:chemistry / Q000494:pharmacology; D003603:Cytotoxins / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D004247:DNA / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D010618:Phenanthrolines / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology
chemical_list: D003603:Cytotoxins; D010618:Phenanthrolines; D003300:Copper; D004247:DNA; D000225:Adenine
keywords: Adenine; Caco-2; DNA-binding; Dinuclear copper(II) complex; HeLa; Phenanthroline