Synthesis, Characterization, and DNA-Binding and -Cleavage Properties of Dinuclear CuIISalophen/Salen Complexes

✍ Scribed by Pulimamidi Rabindra Reddy; Addla Shilpa

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 504 KB
• Volume: 8
• Category: Article
• ISSN: 1612-1872
• DOI: 10.1002/cbdv.201000153

✦ Synopsis

Dinuclear Cu II complexes, [Cu 2 (salophen) 2 ] (1) and [Cu 2 (salen) 2 ] (2), with Schiff bases derived from salicylaldehyde and o-phenylenediamine (ophen) or ethylenediamine (en) were synthesized and characterized. They exhibit square-planar geometry with CuN 2 O 2 coordination, where the dianionic Schiff base acts as a tetradentate N 2 O 2 donor ligand. Calf thymus (CT)-DNA Binding studies revealed that the complexes possess good binding propensities (K b ¼ 3.13 Â 10 5 for 1 and K b ¼ 2.99 Â 10 5 m À 1 for 2). They show good DNA-cleavage abilities under oxidative and hydrolytic conditions. Complex 1 binds and cleaves DNA more efficiently as compared to 2 due to the presence of an extended aromatic phenyl ring which might be involved in an additional stacking interaction with DNA bases. From the kinetic experiments, hydrolytic DNA-cleavage rate constants were determined as 1.54 for 1 and 0.72 h À 1 for 2. The nuclease activities of 1 and 2 are significant, giving rise to (2.03 -2.88) Â 10 7 -fold rate enhancement compared to non-catalyzed DNA cleavage.