Roy, Mithun and Patra, Ashis K and Mukherjee, Arindam and Nethaji, Munirathinam and Chakravarti, Akhil R (2007) Ternary iron(II) complexes of phenanthroline bases showing DNA binding and cleavage activity. In: Indian Journal of Chemistry Section A-Inorganic, Bio-inorganic, Physical, Theoretical & Analytical, 46 (2). pp. 227-237.Full text not available from this repository. (Request a copy)
Ternary iron(II) complexes $[Fe(L1)B](PF_6)_2$ (1-3), where $L^1$ is formed from $FeCl_3$ mediated cyclization of N,N'-(2-hydroxypropane-1,3-diyl)bis(pyridine-2-aldimine) $(L^2)$ and B is a phenanthroline base, viz. 1,10-phenanthroline (phen, 1), dipyrido[3,2-d:2¢,3¢-f]quinoxaline (dpq, 2) and dipyrido[3,2-a:2¢,3¢-c]phenazine (dppz, 3), are synthesized and complex 1 is structurally characterized by X-ray crystallography. The diamagnetic iron(II) complexes with $L^1$ and B showing respective tetradentate and bidentate chelating modes in a $FeN_6$ coordination geometry exhibit two metal-centered visible electronic bands near 520 and 570 nm in MeCN. The complexes bind to calf thymus DNA giving an order: phen (1) < dpq (2) < dppz (3). Control DNA cleavage experiments using supercoiled (SC) pUC19 DNA and distamycin-A suggest major groove binding for the dppz and minor groove binding for the other complexes. The redox active complexes cleave SC DNA to its nicked circular (NC) form with $H_2O_2$ involving hydroxyl radical as the cleavage active species. The complexes show photo-induced DNA cleavage activity at UV light of 365 nm (12 W) in bsence of $H_2O_2$ via singlet oxygen $(^1O_2)$ mechanism. Complexes 2 and 3 having respective photoactive dpq and dppz ligands show relatively poor DNA cleavage activity at visible light.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article belongs to National Institute of Science Communication and Information Resources.|
|Department/Centre:||Division of Chemical Sciences > Inorganic & Physical Chemistry|
|Date Deposited:||29 Jul 2008|
|Last Modified:||27 Aug 2008 13:38|
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