Construction And Functional Study Of Artificial Ion Channels Based On Cyclodextrin-pillararene Hybrid Molecules

In living organisms,there is a well-coordinated,well-defined and high-throughout transmembrane delivery system,which has the function to maintain the stability of the intracellular osmotic pressure,discharge physiological metabolite,and acquire nutrients for the surrounding environment.Transmembrane protein plays a dominant role in transmembrane delivery of water,amino acids,sugars,anions and cations.Potassium channel proteins are responsible for the transportation of potassium ions through biological membrance.Signal transduction can be achieved by changing the concentration of potassium ions inside and outside the cell.In order to study the mechanism of transmembrane transport of potassium ions,a variety of artificial potassium transmembrane delivery systems have been designed and constructed with natural potassium channels as models.Although these studies have made great progress,the establishment of artificial potassium channels with better selectivity and delivery efficiency is still a hot topic in this field.This thesis mainly includes the following two parts:In the first part,bialkynyl pillar[5]arene was prepared as a framework and linked to mono-(6-azido-6-deoxy)-?-cyclodextrin by click reaction to form unimolecular tubular compound.Three artificial channel molecules were synthesized by changing the length of the linker between the pillar[5]arene and the cyclodextrin.The effect of lengths of the linkers on the channel molecules transmembrane transport efficiency and ion selectivity was investigated.The data of experiments showed that such cyclodextrin-pillar[5]arene hybrid molecules could efficiently insert into the lipid bilayer to form artificial ion channels,and exhibited high K~+/Na~+selectivity during transmembrane transport.In the second part,bialkynyl pillar[5]arene was conjugated with monoazido?-CD and monoazido?-CD respectively by click reaction to give several CD-pillar[5]arene-CD hybrid unimolecular tubular compounds.The hybrid molecules were characterized with HPLC,NMR and MS.The transmembrane ion delivery activity of the hybrid molecules was under way.