丁二酸、1,10-菲啰啉构筑稀土配合物的合成、表征及与DNA作用的光谱学研究

首次合成丁二酸-1,10-菲啰啉稀土配合物,并运用光谱法研究配合物与DNA之间的作用机制,为新型抗癌药物的设计开发提供依据。以1,10-菲啰啉(phen)和丁二酸(SA)为配体构筑了3种稀土(La3+,Nd3+,Eu3+)配合物,采用元素分析、红外和紫外光谱及热重分析对配合物性质进行表征测试,确定其化学组成为(RE)2(SA)(phen)·2H2O(RE=La,Nd,Eu)。同时,通过光谱法探讨了这3种配合物分别与DNA作用的机理以及稀土离子种类对作用强度的影响。配合物与DNA作用时,可观察到较明显的吸收峰红移和较大的减色效应现象,同时,中性红(NR)荧光竞争实验发现配合物都能不同程度地猝灭NR-DNA体系的荧光。这3种配合物对DNA均具有较强的插入作用,作用强度为:La(Ⅲ)Nd(Ⅲ)Eu(Ⅲ)。计算了DNA与配合物的结合比、结合常数及一些热力学参数,得出DNA与Eu配合物、Nd配合物、La配合物的结合比分别为4∶1,2∶1和8∶1,Δr Gm0、Δr Sm0,表明这3种配合物与DNA之间的反应均能够自发进行,且作用是熵驱动的。

Synthesis,Characterization of Rare Earth Complexes with Succinic Acid and 1,10-Phenanthroline and Interacting with DNA

Rare earth complexes with succinic acid and 1 ,10-phenanthroline were synthesized first-ly and the interaction with DNA was investigated by spectroscopy method, which provide the basis for the design and development of new anticancer drugs. Three kinds of ternary complexes of rare earth(La3+,Nd3+,Eu3+) with succinic acid (SA) and 1,10-phenanthroline (phen) were synthe-sized in absolute ethanol solution, which were characterized by eleme-ntal analysis, IR, UV-Vis and TG-DTA methods. The compositions of the complexes were confirmed to be (RE)2(SA)(phen)· 2H2O (RE =La, Nd, Eu). Meanwhile, the interactions between complexes and herring sperm DNA have been investigated by electronic absorption spectrum and fluorescence spectrum. The UV absorption spectra showed that the maximal absorption peaks intensity of complexes was weakened with the adding of DNA, and accompanied by a red shift. The combining ratio, binding constant of complex to DNA was obtained and the corresponding thermodynamic parameters were calculated,showed that the interaction between complex and hsDNA was driven mainly by entropy. All the above indicated that the interaction mode of the complexes with DNA belonged to intercalative.