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IJC-A Vol.48A [2009] >
IJC-A Vol.48A(01) [January 2009] >
| Title: | Synthesis, crystal structure and DNA cleavage activity of (aqua)bis(dipyridophenazine)copper(II) complex |
| Authors: | Begum, M S Ameerunisha
Saha, Sounik
Hussain, Akhtar
Chakravarty, Akhil R |
| Keywords: | Bioinorganic chemistry
Hydrolytic cleavage
DNA cleavage
DNA binding
Crystal structure
Copper |
| Issue Date: | Jan-2009 |
| Publisher: | CSIR |
| IPC Code: | Int. Cl. ⁸ C07F1/08; C12N15/00 |
| Abstract: | A copper(II) complex of dipyridophenazine, viz., [Cu(dppz)₂ (H₂O)](ClO₄)₂ (1), 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) Å. 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 (μeff, 1.86 μB). 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 × 10⁵ M⁻¹. It shows significant hydrolytic cleavage of supercoiled pUC19 DNA in dark in the absence of any external agents. The complex exhibits chemical nuclease activity on 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. |
| Page(s): | 9-14 |
| ISSN: | 0376-4710 |
| Source: | IJC-A Vol.48A(01) [January 2009]
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