酚氧桥联型双核Eu(Ⅲ)配合物的合成、表征及与DNA作用研究

Synthesis and characterization of a new phenolate-bridged binuclear Eu(Ⅲ) complex,and interaction between the complex and DNA

本文合成了一种新的双核稀土配合物Na4Eu2L2.3NaNO3.12H2O[L=(2,6-bis[bis(carboxylatomethyl)amino]methyl-4-nitrophenolate),以下缩写为NO2-HXTA],并用红外光谱(IR)、元素分析(EA)等手段对其结构进行了表征。用凝胶电泳实验研究了该双核稀土配合物与pBR322 DNA的作用,发现在37℃时与DNA的切割作用不明显;但在50℃,pH7.2时,配合物在较低浓度(50μmol/L)下即可将70%的超螺旋DNA(CCC带)转化为缺刻产物(OC带);此外,用光谱学手段研究了双核稀土配合物与小牛胸腺(CT)DNA的作用,结果表明,配合物的加入使CTDNA的最大吸收峰(λmax=260 nm)增色和蓝移,并且使溴化乙锭EB-DNA复合物体系的荧光强度减弱。

A new dinuclear metal complex,Na4Eu2L2·3NaNO3·12H2O （ here L = 2,6 -bis [bis （carboxylatomethyl） amino ] methyl-4- nitrophenolate and abbreviated as NO2-HXTA） was synthesized and characterized by IR and EA. Through gel dectrephoresis experiments ,we found that the complex is capable of promoting the cleavage of pBR322 DNA at 50℃ and pH7.2 ,translating 70% of the supereoiled DNA into nicked form at a concentration as low as 50μmol/L. Investigation on the interaction between the complex and CT DNA indicated that the absorbance of CT DNA was increased and the maximum peak （λmax= 260 nm） blueshifted,while the intensity of fluorescence spectra of EB-DNA was gradually weakened.