title: An unlikely DNA cleaving agent: A photo-active trinuclear Cu(II) complex based on hexaazatriphenylene.
abstract: This paper describes the synthesis of a trinuclear Cu(II) complex (4) containing a central 1,4,5,8,9,12-hexaazatriphenylene-hexacarboxylate (hat) core (3). Low, micromolar concentrations of the negatively charged parent ligand 3 and the neutral trinuclear complex 4 were found to photocleave negatively charged pUC19 plasmid DNA with high efficiency at neutral pH (350nm, 50min, 22°C). The interactions of complex 4 with double-helical DNA were studied in detail. Scavenger and colorimetric assays pointed to the formation of Cu(I), superoxide anion radicals, hydrogen peroxide, and hydroxyl radicals during photocleavage reactions. UV-visible absorption, circular dichroism, DNA thermal denaturation, and fluorescence data suggested that the Cu(II) complex contacts double-stranded DNA in an external fashion. The persistent association of ligand 3 and complex 4 with Na(I) and/or other cations in aqueous solution might facilitate electrostatic DNA interactions.
authors.affiliation: Department of Chemistry, Georgia State University, P.O. Box 3965, Atlanta, GA 30302-3965, United States.
authors.forename: Dominique E
authors.initials: DE
authors.lastname: Williams
authors.affiliation: Department of Chemistry, Georgia State University, P.O. Box 3965, Atlanta, GA 30302-3965, United States.
authors.forename: Christina M
authors.initials: CM
authors.lastname: Fischer
authors.affiliation: Department of Chemistry, Georgia State University, P.O. Box 3965, Atlanta, GA 30302-3965, United States.
authors.forename: Miki
authors.initials: M
authors.lastname: Kassai
authors.affiliation: Departamento de Química Orgánica y Química Inorgánica, Universidad de Alcalá, 28871-Alcalá de Henares, Madrid, Spain.
authors.forename: Lourdes
authors.initials: L
authors.lastname: Gude
authors.affiliation: Departamento de Química Orgánica y Química Inorgánica, Universidad de Alcalá, 28871-Alcalá de Henares, Madrid, Spain.
authors.forename: María-José
authors.initials: MJ
authors.lastname: Fernández
authors.affiliation: Departamento de Química Orgánica y Química Inorgánica, Universidad de Alcalá, 28871-Alcalá de Henares, Madrid, Spain. Electronic address: antonio.lorente@uah.es.
authors.forename: Antonio
authors.initials: A
authors.lastname: Lorente
authors.affiliation: Department of Chemistry, Georgia State University, P.O. Box 3965, Atlanta, GA 30302-3965, United States. Electronic address: kbgrant@gsu.edu.
authors.forename: Kathryn B
authors.initials: KB
authors.lastname: Grant
mesh_terms: D001372:Aza Compounds / Q000737:chemistry* / Q000494:pharmacology*; D002911:Chrysenes / Q000737:chemistry* / Q000494:pharmacology*; D002942:Circular Dichroism; D003124:Colorimetry; D003300:Copper / Q000737:chemistry* / Q000494:pharmacology*; D004247:DNA / Q000187:drug effects* / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000737:chemistry; D015394:Molecular Structure; D055668:Photochemical Processes; D013481:Superoxides / Q000737:chemistry
chemical_list: D001372:Aza Compounds; D002911:Chrysenes; C533582:azatriphenylene; D013481:Superoxides; D003300:Copper; D004247:DNA; D006861:Hydrogen Peroxide
keywords: Copper(II); DNA; Hexaazatriphenylene; Photocleavage; Polypyridyl