Approach toward Artificial Enzyme Models Using Water-soluble Cyclophanes with Hyrophobic Cavities

本论文针对含有二苯基甲烷单元的环番化合物在水溶液中和膜表面的人工酶模型中的应用进行了研究，得到了以下结果.合成了在含有二苯基甲烷单元的环蕃大环上引入咪唑基或巯基作为催化官能团的催化环蕃，并比较了它们在水溶液（pH 8.65）中促进酯合成的能力。虽然3.8倍的加速观察到一个环番具有咪唑基，控制实验与添加的非反应性的客体或4-甲基-咪唑没有环番环表明，加速由咪唑基环番是不是由于与客体的反应包括在环番腔。这些结果表明，设计催化基团靠近客体活性位的催化环芳的必要性.合成了一种具有光学活性的阴离子型C_2对称结构的环蕃，该环蕃具有两个羟基，是一种新型的手性疏水空腔，能够引入催化功能基团。该环蕃在水溶液中与阳离子芳香客体（K_3-10^3M^）有较强的络合作用<-1>（pD12.8）。合成了一系列具有长烷基链的亲脂性cyclophanes，以实现在膜表面的分子识别，通过使用PVC支撑的液膜系统评价为客人诱导的膜电位变化。在苯环的一侧具有确定的带电基团且在另一侧具有亲脂性烷基链的环蕃给出最大的电势变化，表明设计界面受体的重要原则。

Studies aiming at application of cyclophanes having diphenylmethane units to artificial enzyme models in aqueous solutions and at membrane surfaces were carried out, and the following results were obtained.1. Catalytic cyclophanes in which an imidazolyl or thiol group as a catalytic functional group was introduced to a cyclophane macrocycle having diphenylmethane units were synthesized, and their abilities to accelerate ester docomposition were compared in aqueous solution (pH 8.65). Although 3.8-fold acceleration was observed for a cyclophane having an imidazolyl group, control experiments with addition of a nonreactive guest or 4-methyl-imidazole without a cyclophane ring showed that the acceleration by the imidazolyl cyclophane was not due to the reaction with a guest included in the cyclophane cavity. These results manifested the necessity of the design of catalytic cylophanes in which the catalytic group is located in close proximity to the reactive site of the included guest.2. An optically active, anionic cyclophane having a C_2-symmetrical structure with two OH groups was synthesized as a new type of chiral hydrophobic cavity that is capable of introducing catalytic functional groups. This cyclophane showed strong complexation to cationic aromatic guests (K_3-10^3M^<-1>) in aqueous solution (pD12.8).3. A series of lipophilic cyclophanes having long alkyl chains were synthesized to achieve molecular recognition at a membrane surface, evaluated as guest-induced changes in membrane potential by using PVC-supported liquid membrane systems. A cyclophane having a definite charged group on one side and a lipophilic alkyl chain on the other side of the benzene rings gave greatest potential changes, indicating an important principle for designing interfacial receptors.