Synthesis, characterization, cellular uptake and interaction with native DNA of a bis(pyridyl)-1,2,4-oxadiazole copper(II) complex.
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).
Terenzi
Alessio
A
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.
Barone
Giampaolo
G
Piccionello
Antonio Palumbo
AP
Giorgi
Gianluca
G
Guarcello
Annalisa
A
Portanova
Patrizia
P
Calvaruso
Giuseppe
G
Buscemi
Silvestre
S
Vivona
Nicolò
N
Pace
Andrea
A
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*
D008024:Ligands; D009942:Organometallic Compounds; D010069:Oxadiazoles; D011725:Pyridines; D003300:Copper; D004247:DNA