title: Synthesis, characterization, and DNA-binding properties of the Ln(III) complexes with 6-hydroxy chromone-3-carbaldehyde-(2'-hydroxy) benzoyl hydrazone.
abstract: A new ligand, 6-hydroxy chromone-3-carbaldehyde-(2'-hydroxy) benzoyl hydrazone (L), was prepared by condensation of 6-hydroxy-3-carbaldehyde chromone (CDC) with 2-hydroxy benzoyl hydrazine. Its four rare earth complexes have been synthesized and characterized on the basis of elemental analyses, molar conductivities, mass spectra, 1H NMR, thermogravimetry/differential thermal analysis (TG-DTA), UV-vis spectra, fluorescence spectra, and IR spectra. The general formula of the complexes is [LnL2.(NO3)2].NO3 [Ln=La(1), Sm(2), Dy(3), Eu(4)]. Spectrometric titration, ethidium bromide displacement experiments, and viscosity measurements indicate that Eu(III) complex and ligand, especially the Eu(III) complex, strongly bind with calf-thymus DNA, presumably via an intercalation mechanism. The intrinsic binding constants of Eu(III) complex and ligand with DNA were 3.55 x 10(6) and 1.33 x 10(6)M(-1) through fluorescence titration data, respectively. In addition, the suppression ratio for O2-* and OH* of the ligand and its complexes was studied by spectrophotometric methods. The experimental results show that La (1), Sm (2), and Eu (4) complexes are better effective inhibitor for OH* than that of mannitol. It indicates that the complexes have the activity to suppress O2-* and OH* and exhibit more effective antioxidants than ligand alone.
authors.affiliation: College of Chemistry and Chemical Engineering, State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, PR China.
authors.forename: Bao-dui
authors.initials: BD
authors.lastname: Wang
authors.forename: Zheng-Yin
authors.initials: ZY
authors.lastname: Yang
authors.forename: Tian-rong
authors.initials: TR
authors.lastname: Li
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry*; D001667:Binding, Competitive; D002867:Chromones / Q000138:chemical synthesis* / Q000737:chemistry*; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D004419:Dysprosium / Q000737:chemistry; D005063:Europium / Q000737:chemistry; D006835:Hydrazones / Q000138:chemical synthesis* / Q000737:chemistry*; D007811:Lanthanum / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D012493:Samarium / Q000737:chemistry
chemical_list: C514206:6-hydroxy chromone-3-carbaldehyde-(2'-hydroxy) benzoyl hydrazone; D000970:Antineoplastic Agents; D002867:Chromones; D006835:Hydrazones; D004419:Dysprosium; D012493:Samarium; D005063:Europium; D007811:Lanthanum; D004247:DNA