Development and application of nanotubes based on polytheonamides

在进一步的结构研究中，合成了44位氨基酸残基的结构候选物<th>。结果表明，该产物的结构为β，β-二甲基甲硫氨酸。这通过聚茶酰胺B通过氧化和还原的化学反应得到证实。同时，聚茶酰胺A的结构被牢固地确立为非对映异构体，其不同之处在于44位残基中硫原子的构型<th>。用<th>BrCN反应得到C-末端内酯，然后用气相色谱法在手性固定相上进行分析，确定了44-位残基的绝对立体化学，并考察了它们的通道形成活性。聚茶酰胺A和B都被掺入脂质双层中，并与细菌线性肽短杆菌肽A一样传导单价阳离子。聚茶酰胺形成的通道呈开放和闭合状态。其机制有待进一步研究。

In further structural study of polytheonamides, the candidates of the structures for the 44^<th> residue amino acid were synthesized. As the result, the structure of the pertinent resudue was concluded to be β,β-dimethylmethionine. This was confirmed by chemical reaction of polytheonamide B by oxidation and reduction. In the meantime, the structure of polytheonamide A was firmly established as a diastereomer differing in the configuration of the sulfur atom in the 44^<th> residue. The absolute stereochemistry of the 44^<th> residue was determined by BrCN reaction of polytheonamides affording the C-terminal lactone, and the following GC analysis on a chiral stationary phase.Channel forming activity of polytheonamides were examined. Both polytheonamides A and B are incorporated into the lipid bilayer and conducted monovalent cations as does bacterial linear peptide gramicidin A. The channel formed by polytheonamides showed open and close state. The mechanism of this character needs further study.