title: Synthesis, characterization, cellular uptake and interaction with native DNA of a bis(pyridyl)-1,2,4-oxadiazole copper(II) complex.
abstract: The copper(II) complex of 3,5-bis(2'-pyridyl)-1,2,4-oxadiazole was synthesized and characterized. X-Ray crystallography revealed that the complex consists of a discrete [Cu(3,5-bis(2'-pyridyl)-1,2,4-oxadiazole)(2)(H(2)O)(2)](2+) cation and two ClO(4)(-) anions. The Cu(II) coordination sphere has a distorted octahedral geometry and each ligand chelates the copper ion through the N(4) nitrogen of the oxadiazole ring and the nitrogen of one pyridine moiety. The coordinated water molecules are in cis position and each of them is H-bonded to the 5-pyridyl nitrogen of the oxadiazole ligand and to an oxygen of the perchlorate anion. Biological assays showed that, despite the free ligand not being effective, [Cu(3,5-bis(2'-pyridyl)-1,2,4-oxadiazole)(2)(H(2)O)(2)](2+) reduced the vitality of human hepatoblastoma HepG2 and colorectal carcinoma HT29 cells in a dose- and time-dependent manner. The interaction of the cationic copper complex with native DNA was investigated by variable-temperature UV-vis spectroscopy, circular dichroism, viscosity and gel electrophoresis, indicating that it is a groove binder with binding constant K(b) = 2.2 × 10(4) M(-1).
authors.affiliation: Dipartimento di Chimica Inorganica e Analitica Stanislao Cannizzaro, Università degli Studi di Palermo, Viale delle Scienze, Parco d'Orleans II, Edificio 17, 90128, Palermo, Italy.
authors.forename: Alessio
authors.initials: A
authors.lastname: Terenzi
authors.forename: Giampaolo
authors.initials: G
authors.lastname: Barone
authors.forename: Antonio Palumbo
authors.initials: AP
authors.lastname: Piccionello
authors.forename: Gianluca
authors.initials: G
authors.lastname: Giorgi
authors.forename: Annalisa
authors.initials: A
authors.lastname: Guarcello
authors.forename: Patrizia
authors.initials: P
authors.lastname: Portanova
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Calvaruso
authors.forename: Silvestre
authors.initials: S
authors.lastname: Buscemi
authors.forename: Nicolò
authors.initials: N
authors.lastname: Vivona
authors.forename: Andrea
authors.initials: A
authors.lastname: Pace
mesh_terms: D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003300:Copper / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D006801:Humans; D008024:Ligands; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D010069:Oxadiazoles / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*
chemical_list: D008024:Ligands; D009942:Organometallic Compounds; D010069:Oxadiazoles; D011725:Pyridines; D003300:Copper; D004247:DNA