Premium
DNA‐Binding Study of Nickel(II) and Zinc(II) Complexes with Two Novel Chromenone‐Based Schiff ‐Base Ligands
Author(s) -
Qin DongDong,
Yang ZhengYin,
Li TianRong,
Qi GaoFei
Publication year - 2009
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.200800350
Subject(s) - chemistry , molar conductivity , schiff base , nickel , zinc , binding constant , methylene , dna , crystallography , infrared spectroscopy , stereochemistry , spectroscopy , fluorescence , nuclear chemistry , medicinal chemistry , inorganic chemistry , binding site , elemental analysis , organic chemistry , biochemistry , physics , quantum mechanics
Two new chromenone‐based Schiff ‐base ligands, 3‐{[(1,5‐dihydro‐3‐methyl‐5‐thioxo‐4 H ‐1,2,4‐triazol‐4‐yl)imino]methyl}‐6‐hydroxy‐4 H ‐1‐benzopyran‐4‐one ( L 1 ) and 2,2′‐bis[(6‐hydroxy‐4‐oxo‐4 H ‐1‐benzopyran‐3‐yl)methylene]carbonothioic dihydrazide ( L 2 ), and their Ni II and Zn II complexes were prepared. All the complexes were characterized by elemental analysis, IR data, and molar conductivity. The binding of these four complexes to calf‐thymus DNA was carefully investigated by UV/VIS spectroscopy, fluorescence spectroscopy, viscosity measurements, and CD spectra. The experimental results indicate that the four complexes bind to calf‐thymus DNA in an intercalative mode, with the intrinsic binding constants ( K ) of 3.94⋅10 4 ([Ni L 1 ]), 5.15⋅10 3 ([Zn L 1 ]), 4.12⋅10 4 ([Ni L 2 ]), and 3.75⋅10 4 M −1 ([Zn L 2 ]). These data show that the complexes of L 2 can interact more strongly with DNA than complexes of L 1 , and the Ni II complexes have a higher binding constant than Zn II complexes.