Crystal Structures of Aza-β³-peptides, A New Class of Foldamers Relying on a Framework of Hydrazinoturns

Crystals of aza-β3-peptides have been obtained. This gives the first opportunity for hydrazino peptides, in the sense of oligomers built exclusively with α-hydrazinoacetic units, to be observed in the solid state. The structures make it clear that the H-bond network developed by aza-β3-peptides differs radically from those of the corresponding β3-peptides but strongly resembles that of the α-aminoxy peptides. Our study contributes to the current interest in hydrazino peptides as an extension of the β-peptide concept.已成功获取氮杂-β3-肽（aza-β3-peptides）的晶体。这为仅由α-肼基乙酸单元（α-hydrazinoacetic units）构建的低聚物类肼基肽（hydrazino peptides）提供了首次在固态下被观测到的契机。结构解析结果清晰显示，氮杂-β3-肽所形成的氢键（H-bond）网络，与对应β3-肽的氢键网络截然不同，但与α-氨基氧基肽（α-aminoxy peptides）的氢键网络高度相似。本研究为当前以β-肽（β-peptide）概念为延伸方向的肼基肽研究热点提供了有益的实验支撑。