The association of two ruthenium(II) complexes [Ru(phen)₂(o-HPIP)]²⁺ (Ru1; phen = 1,10–phenanthroline, o-HPIP = 2-(2-hydroxyphenyl)-imidazo[4,5-f][1,10] phenanthroline) and [Ru(phen)₂(m-HPIP)]²⁺ (Ru2; m-HPIP = 2-(3-hydroxyphenyl)–imidazo[4,5-f][1,10]phenan-

throline) with the RNA poly(U)·poly(A)⁎poly(U) triplex has been investigated by spectrophotometric titrations and melting experiments in this work. All experimental data reveal an intercalative triplex-binding mode of the two complexes, whereas the binding constant for Ru1 is significantly higher than that for Ru2. Circular dichroism spectroscopic investigations show that the two complexes could bind to the chiral environment of the triplex, but the triplex perturbation effects induced by Ru1 are more marked. Thermal denaturation experiments demonstrate that both Ru1 and Ru2 display a large binding preference and stabilizing effect for the third strand over the Watson–Crick base-paired duplex of the triplex. However, the third-strand stabilizing effect of Ru1 is much more effective than that of Ru2. The obtained results suggest that positions of the phenolic group on the main ligands have significant effect on the binding of the two complexes with poly(U)·poly(A)⁎poly(U) triplex

两种钌（II）配合物[Ru（phen）₂（o -HPIP）] ²⁺（Ru 1； phen = 1,10-菲咯啉，o -HPIP = 2-（2-羟苯基）-咪唑[4] ，5- f ] [1,10]菲咯啉）和[Ru（phen）₂（m -HPIP）] ²⁺（Ru 2 ; m -HPIP = 2-（3-羟苯基）-咪唑[4,5- f ] [1,10] phenan-

本文通过分光光度滴定法和熔解实验研究了具有RNA poly（U）·poly（A）⁎poly（U）三重态的RNA的脯氨酸。所有实验数据都揭示了两种复合物的插入三重结合模式，而Ru 1的结合常数明显高于Ru 2的结合常数。圆二色性光谱研究表明，两种络合物可以与三链体的手性环境结合，但Ru 1引起的三链体扰动效应更为明显。热变性实验表明Ru 1和Ru 2在三链的沃森-克里克碱基配对的双链中，对第三链显示出较大的结合偏好和稳定作用。但是，Ru 1的第三链稳定作用比Ru 2稳定得多。获得的结果表明，酚基在主要配体上的位置对两个复合物与poly（U）·poly（A）⁎poly（U）三元体的结合具有显着影响。