电中性分子间相互作用分析的毛细管电泳方法研究

使用具有负有效淌度的十二烷基磺酸钠胶束赋予中性分子有效淌度,以中性主体分子18-冠-6和中性客体分子对-硝基苯胺形成中性超分子包结化合物为实例,建立了中性分子相互作用的毛细管电泳分析方法,发现对-硝基苯胺和18-冠-6与SDS的相互作用存在相当的差异.测得18-冠-6和对-硝基苯胺的lgK为4.14,18-冠-6与2-氨基吡啶、18-冠-6与SDS以及SDS与2-氨基吡啶的lgK分别为3.65,3.13和1.15.

Studies on the Interaction Analysis of Neutral Molecules by Using Capillary Electrophoresis

Because neutral molecules have no absolute mobilities, the capillary electrophoresis utilizing peak-shifting experiment can not be used to analyze the interaction of them. In this paper, the neutral molecules have been imparted apparent mobilities by sodium dodecyl sulfate(SDS) micelle, which has negative charge and negative apparent mobilities. The 18-crown-6 and p-nitroaniline without charge under a controlled condition were used as the samples of neutral molecules, and they were able to form a neutral supramolecule by interaction. Through the research, an interaction analytical method by using capillary electrophoresis is set up. The logarithm of binding constant of 18-crown-6 with p-nitroaniline was obtained to be 4.14. In addition, comparative differences of hydrophobicity between 18-crown-6 and p-nitroaniline to SDS was found, respectively. Further more, for multiple interactions, the interaction analytical method of supramolecules has also been set up, which has more accuracy and availability. The logarithms of binding constant of 18-crown-6 to 2-aminopyridine and SDS, and 2-aminopyridine to SDS were obtained to be 3.65, 3.13 and 1.15, respectively. After the development of the peak-shifting was applied to the neutral molecules, the principles, available experimental conditions, and assumptions in the measurement have been discussed. This approach in this paper could be developed as an interaction analysis method of multiple components in a complex system.