Synthesis, structure, DNA binding and oxidative cleavage activity of ternary (l-leucine/isoleucine) copper(II) complexes of heterocyclic bases

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摘要：

Six ternary α-amino acid copper(II) complexes of the general formula [Cu(AA)(B)(HO)](X) (–), where AA is -leu=-leucine (–) or -ile=-isoleucine (–), B is a ,-donor heterocyclic base, viz. 2,2′-bipyridine (bpy, , ), 1,10-phenanthroline (phen, , ) and dipyrido[3,2:2′,3′-]quinoxaline (dpq, , ) and -ile (,) have been structurally characterized by X-ray crystallography. The complexes show a distorted square-pyramidal (4+1) CuNO coordination geometry. The one-electron paramagnetic complexes display a d–d band near 600nm in water and show a cyclic voltammetric response due to a Cu(II)/Cu(I) couple near 0.1V (vs. SCE) in DMF-0.1M TBAP. All complexes are 1:1 electrolytes. Binding interactions of the complexes with calf thymus DNA (CT-DNA) have been investigated by absorption, emission, viscosity and DNA melting studies. The phen and dpq complexes are avid binders to the calf thymus DNA, giving an order: (,) (dpq)>(,) (phen)?(,) (bpy). The bpy complexes do not show any apparent binding to the DNA and hence show poor DNA cleavage activity. The phen and dpq complexes (,,,) show efficient oxidative cleavage of pUC19 supercoiled DNA (SC-DNA) in the presence of the reducing agent 3-mercaptopropionic acid (MPA) involving hydroxyl radical (Graphical abstractThe synthesis, characterization, DNA binding and "chemical nuclease" activity of ternary copper(II) complexes, [Cu(AA)(B)(HO)](X) containing AA=-leu/ile and planar phenanthroline bases (B), are described. The complexes are avid DNA binders and show oxidative DNA cleavage activity involving formation of a hydroxyl radical in the presence of a reducing agent.

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关键词：

DNA binding DNA cleavage Crystal structure llPhenanthroline base

DOI：

10.1016/j.poly.2007.12.026

被引量：

236

年份：

2008