Construction and Control of Helical Supramolecules Based on Sequential Information of Carbon-Chains

我们对类固醇包合物的研究已经有十多年了。在这个研究项目中，我们的目标是基于手性碳链的序列信息来构建和控制包裹体晶体中的螺旋超分子。这样的研究可能使我们能够建立分子信息的概念和手性碳链化合物的表达，如甾体。主要研究结果如下：1.从市售胆酸和脱氧胆酸出发，合成了多种含有序列信息的甾体类化合物。在大多数情况下，这类化合物形成由螺旋组装组成的包合物晶体。通过对100多个客体的包合行为的考察，考察了甾体主客体的包合行为。我们确定了包含的来宾组件的范围。每个主机的范围因情况而异。我们积累了从大小、形状、手性和极性的角度考虑主客体络合可能的机理所需的包合数据。我们用粉末和单晶X射线结晶学的方法对所得包合物进行了分析，发现了50多个螺旋结构的包合物。利用各种软件从螺旋结构的各个方面对螺旋总成进行了分析。例如，分子图形学研究帮助我们评估了原始分子结构和得到的螺旋结构之间的关系。我们证实了氢键基团之间的多重结合可能在决定螺旋结构中起着重要的作用。现在我们认为，手性碳链化合物倾向于在可转移氢键和范德华相互作用的基础上构建全面的螺旋组装，这是由于表面上的两亲性。

We have been studying on inclusion compounds of steroids over ten years. In this research project we aim to construct and control helical supramolecules in inclusion crystals on the basis of sequential information of chiral carbon-chains. Such a study may enable us to establish the concept of molecular information and expression of chiral carbon-chain compounds, such as steroids. The results are summarized as follows ;1. We synthesized many steroidal derivatives involving sequential information, starting from commercially availabe cholic and deoxycholic acids. Such compounds were found to form inclusion crystals composed of helical assemblies in most of the cases.2. The inclusion behaviors of the steroidal hosts were checked by using more than one hundred guests. We determined a scope of the guest components included. The scope for each host varied from one case to another. We accumulated inclusion data necessary for considering possible mechanism of the host-guest complexation from a viewpoint in size, shape, chirality and polarity.3. We analyzed the resulting inclusion compounds by means of powder and single crystal X-ray crystallography, leading to the finding of over fifty helical structures of the inclusion compounds. We analyzed the helical assemblies from various aspects of the helical structures by using various softwares. For example, molecular graphics study helped us to evaluate a relation between the original molecular structures and the resulting helical structures.4. We confirmed that multiple combinations among the hydrogen-bonding groups may play an important role in determining the helical structures. Now we believe that chiral carbon-chain compounds tend to construct comprehensive helical assemblies on the basis of diversible hydrogen bonds and van der Waals interaction due to facially amphiphilicity.