Biological evaluation of a novel water soluble sulphur bridged binuclear copper(II) thiosemicarbazone complex

The reaction of 2-oxo-1,2-dihydroquinoline-3-carbaldehyde 4(N,N)-dimethylthiosemicarbazone (HL) with copper(II) nitrate in methanol yielded water soluble [{Cu(L)(CH3OH)}(2)](NO3)(2)center dot H2O. Structural analysis revealed that the complex consists of centrosymmetric binuclear entities containing square-pyramidal copper(II) ions bridged through the sulfur atoms. The spectroscopic experimental evidences strongly suggested that the ligand and complex could interact with calf thymus DNA (CT-DNA) through intercalation. A gel electrophoresis assay demonstrated the ability of the complex to cleave the pBR322 plasmid DNA. The complex also exhibited a strong binding to bovine serum albumin (BSA) over the ligand. Investigations of antioxidative properties showed that the complex has strong radical scavenging properties. Further, the cytotoxic effect of the complex was examined on HeLa, Hep G2, and HEp-2, which showed that the complex exhibited substantial cytotoxic specificity on HeLa over the other two. (C) 2011 Elsevier Masson SAS. All rights reserved.