Synthesis, crystal structure and DNA cleavage activity of (aqua)bis(dipyridophenazine)copper(II) complex

Begum, MS Ameerunisha and Saha, Sounik and Hussain, Akhtar and Chakravarthy, Akhil R (2009) Synthesis, crystal structure and DNA cleavage activity of (aqua)bis(dipyridophenazine)copper(II) complex. In: Indian Journal Of Chemistry Section A-Inorganic Bio-Inorganic Physical Theoretical & Analytical Chemistry, 48 (1). pp. 9-14.

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Abstract

A copper(II) complex of dipyridophenazine, viz., [Cu(dppz)(2)(H2O)](ClO4)(2) (I), has been prepared and structurally characterized by X-ray crystallography. The crystal structure of the complex shows a five-coordinate structure in which two N,N-donor dipyridophenazine (dppz) and one aqua ligand bind to the copper(II) center giving Cu-O and Cu-N bond distances in the range of 1.981(6) to 2.043(6) angstrom. The ESI-MS spectrum of 1 in MeCN shows a peak at m/z value of 313 (100%) indicating the dissociation of the aqua ligand in the solution phase. The complex is one-electron paramagnetic (mu(eff), 1.86 mu(B)). It displays a quasi-reversible Cu(II)/Cu(I) redox process at 0.096 V. The complex is an avid binder to CT DNA giving a binding constant value of 3.5 x 10(5) M-1. It shows significant hydrolytic cleavage of supercoiled pUC19 DNA in dark ill the absence of any external agents. The complex exhibits chemical nuclease activity oil treatment with 3-mercaptopropionic acid as a reducing agent forming hydroxyl radicals. Complex 1 is a model synthetic nuclease and hydrolase showing both modes of DNA cleavage under different reaction conditions. The DNA cleavage activity of 1 is significantly better than its phen analogue but similar to that of the bis-dpq complex.

Item Type:	Journal Article
Publication:	Indian Journal Of Chemistry Section A-Inorganic Bio-Inorganic Physical Theoretical & Analytical Chemistry
Publisher:	National Institute of Science Communication and Information Resources
Additional Information:	Copyright of this article belongs to National Institute of Science Communication and Information Resources.
Keywords:	Bioinorganic chemistry;Hydrolytic cleavage;DNA cleavage;DNA binding;Crystal structure;Copper
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry
Date Deposited:	06 Nov 2009 09:03
Last Modified:	19 Sep 2010 05:28
URI:	http://eprints.iisc.ac.in/id/eprint/19486

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