title: Synthesis, Characterization, DNA Interaction, and Antitumor Activities of La (III) Complex with Schiff Base Ligand Derived from Kaempferol and Diethylenetriamine.
abstract: A novel La (III) complex, [LaL(H2O)3]NO3 ·3H2O, with Schiff base ligand L derived from kaempferol and diethylenetriamine, has been synthesized and characterized by elemental analysis, IR, UV-visible, (1)H NMR, thermogravimetric analysis, and molar conductance measurements. The fluorescence spectra, circular dichroism spectra, and viscosity measurements and gel electrophoresis experiments indicated that the ligand L and La (III) complex could bind to CT-DNA presumably via intercalative mode and the La (III) complex showed a stronger ability to bind and cleave DNA than the ligand L alone. The binding constants (K b ) were evaluated from fluorescence data and the values ranged from 0.454 to 0.659 × 10(5) L mol(-1) and 1.71 to 17.3 × 10(5) L mol(-1) for the ligand L and La (III) complex, respectively, in the temperature range of 298-310 K. It was also found that the fluorescence quenching mechanism of EB-DNA by ligand L and La (III) complex was a static quenching process. In comparison to free ligand L, La (III) complex exhibited enhanced cytotoxic activities against tested tumor cell lines HL-60 and HepG-2, which may correlate with the enhanced DNA binding and cleaving abilities of the La (III) complex.
authors.affiliation: Rongchang Campus, Southwest University, Chongqing 402460, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Pharmacy College, Ningxia Medical University, Yinchuan 750004, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Huang
authors.affiliation: School of Chemistry and Material Science, Guizhou Normal University, Guiyang 550001, China.
authors.forename: Jin-Sheng
authors.initials: JS
authors.lastname: Zhang
authors.affiliation: Rongchang Campus, Southwest University, Chongqing 402460, China.
authors.forename: Xin-Bin
authors.initials: XB
authors.lastname: Yang