Association of structural modifications with bioactivity in three new copper(II) complexes of Schiff base ligands derived from 5-chlorosalicylaldehyde and amino acids.

Association of structural modifications with bioactivity in three new copper(II) complexes of Schiff base ligands derived from 5-chlorosalicylaldehyde and amino acids. J Inorg Biochem. 2015 Mar 2;146:52-60 Authors: Li A, Liu YH, Yuan LZ, Ma ZY, Zhao CL, Xie CZ, Bao WG, Xu JY Abstract Three novel structurally associated copper(II) complexes [Cu(II)(SalCl-Gly)(H2O)2] (1), [Cu(II)(SalCl-Ala)(H2O)] (2) and [Cu(II)(SalCl-Gly)(bipy)]·0.5H2O (3) (SalCl-Gly=5-chloro-2-hydroxybenzylidene-glycine, SalCl-Ala=5-chloro-2-hydroxybenzylidene-alanine, bipy=2,2'-bipyridine) have been synthesized and characterized by X-ray crystallography, elemental analysis, IR and fluorescence spectroscopy. Single-crystal diffraction reveals that complex 1 is an infinite 1D zigzag chain in which SalCl-Gly serves as both a chelating and a bridging ligand, while complexes 2 and 3 are mononuclear. Cu(II) ions in complexes 1-3 exhibit distorted quasi-hexacoordinated octahedral, tetracoordinated square planar, and pentacoordinated square pyramid geometry, respectively. Their interactions with calf thymus DNA (CT-DNA) have been investigated by viscosity measurements and fluorescence spectroscopy. The apparent binding constant (Kapp) values for 1-3 are 1.02×10(5), 0.98×10(5) and 1.57×10(5)M(-1), respectively. All complexes displayed efficient oxidative cleavage of supercoiled DNA in the presence of H2O2. Complex 2, whose ligand can be regarded as a methyl-modification ...
Source: Journal of Inorganic Biochemistry - Category: Biochemistry Authors: Tags: J Inorg Biochem Source Type: research