Unique folded structures of natural and synthetic oligomers are the most fundamental basis for their unique functions. N-substituted β-peptides, or β-peptoids, are synthetic oligomers of great potential to fold into diverse three-dimensional structures because of the existence of four rotatable bonds in a monomer and its highly modular synthetic accessibility. However, the existence of the four rotatable bonds poses a challenge for conformational control of β-peptoids. Here, we report a strategy for per-residue programming of two dihedral angles of β-peptoids, which is useful for restricting conformational space of the oligomers. The oligomer was found to form a unique loop conformation that is stabilized by the backbone rotational restrictions. Circular dichroism and NMR spectroscopic analyses and X-ray crystallographic analysis of the oligomer are presented. The strategy would significantly facilitate the discovery of many more unique folded structures of β-peptoids.

中文翻译：

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通过骨架取代的β-拟肽的多个骨架二面角的每个残基程序

天然和合成低聚物的独特折叠结构是其独特功能的最基本基础。N-取代的 β-肽或 β-类肽是合成低聚物，具有折叠成不同三维结构的巨大潜力，因为单体中存在四个可旋转的键，并且具有高度模块化的合成可访问性。然而，四个可旋转键的存在对β-拟肽的构象控制提出了挑战。在这里，我们报告了 β-peptoids 的两个二面角的每个残基编程的策略，这对于限制寡聚体的构象空间很有用。发现低聚物形成独特的环构象，该构象通过骨架旋转限制而稳定。给出了低聚物的圆二色性和 NMR 光谱分析和 X 射线晶体学分析。该策略将显着促进发现许多更独特的 β-拟肽折叠结构。