Synthesis, crystal structure, DNA cleavage properties, and protein binding activities of an unsymmetrical dinuclear copper(II) complex

Abstract

[Cu₂L(phen)(H₂O)₃(ClO₄)](ClO₄)₃ {phen = 1,10-phenanthroline, L = 4-((bis(pyridine2-ylmethyl)amino)methyl)-N,N-bis(pyridin-2-ylmethyl)aniline} was prepared and characterized by physical chemical techniques. The X-ray single-crystal structure analysis shows an unsymmetrical dinuclear species. The interaction of the complex with calfthymus DNA (CT-DNA) was studied by various spectroscopic and viscosity measurements, which indicate that the complex can interact with CT-DNA through intercalation. In the presence of H₂O₂, the complex can cleave pBR322 DNA more efficiently and hydroxyl radicals (HO^.) may serve as the major cleavage active species. Interactions of the compound with bovine serum albumin (BSA) were also investigated using UV−Vis and fluorescence spectroscopic methods. The results show that the complex quenches the intrinsic fluorescence of BSA by a static quenching mechanism.

The X-ray single-crystal structure analysis shows that the complex is an unsymmetrical dinuclear species.

Keywords:

• Unsymmetrical ligand
• DNA Cleavage
• Intercalation mode
• A static quenching mechanism

Funding

This work was supported by the National Natural Science Foundation of China [21171101 21071083 and 21001066]; NFFTBS [No. J1103306]; Tianjin Science Foundation [No. 12JCYBJC13600].