Synthesis, Characterization, Antioxidant Activity and DNA-Binding Studies of Three Rare Earth (III) Complexes with 1-(4-Aminoantipyrine)-3-tosylurea Ligand

• Published in: Journal of fluorescence 2009, Vol.19 (1), p.63-72
• Main Authors: Xi, Pin-xian, Xu, Zhi-hong, Liu, Xiao-hui, Chen, Feng-juan, Zeng, Zheng-zhi, Zhang, Xiao-wen, Liu, Ying
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Antioxidants - chemical synthesis; Antioxidants - chemistry; Antioxidants - pharmacology; Antipyrine - analogs & derivatives; Antipyrine - chemistry; Binding Sites; Biochemistry; Biological and Medical Physics; Biomedical and Life Sciences; Biomedicine; Biophysics; Biotechnology; Circular Dichroism; DNA - chemistry; DNA - drug effects; Dose-Response Relationship, Drug; Electrodes; Hydroxyl Radical - chemistry; Ligands; Metals, Rare Earth - chemistry; Molecular Structure; Organometallic Compounds - chemical synthesis; Organometallic Compounds - chemistry; Organometallic Compounds - pharmacology; Original Paper; Spectrometry, Fluorescence; Spectrophotometry, Infrared; Spectrophotometry, Ultraviolet; Structure-Activity Relationship; Urea - analogs & derivatives; Urea - chemistry; Viscosity
• ISSN: 1053-0509; 1573-4994
• DOI: 10.1007/s10895-008-0381-7

1-(4-Aminoantipyrine)-3-tosylurea (H 2 L) and its three lanthanide (III) complexes, M(H 2 L) 3 3NO 3 [where M = Nd(III), Sm(III) and Eu(III)], have been synthesized and characterized. In addition, the DNA-binding properties of the three complexes have been investigated by UV–vis (ultraviolet and visible) absorption spectroscopy, fluorescence spectroscopy, circular dichroism (CD) spectroscopy, cyclic voltammetry, and viscosity measurements. Results suggest that the three complexes bind to DNA via a groove binding mode. Furthermore, the antioxidant activity (superoxide and hydroxyl radical) of the metal complexes was determined by using spectrophotometer methods in vitro. These complexes were found to possess potent antioxidant activity and be better than standard antioxidants like vitamin C and mannitol. Absorption spectra of the complex 3 inTris-HCl buffer upon addition of calf-thymus DNA. [complex]=1×10 -5 M, [DNA]=(0-1) ×10 -5 M. Arrow shows the absorbance changing upon increasing DNA concentrations. Inset: plots of [DNA]/(ε a – ε f ) versus [DNA] for the titration of DNA with the complex.