作者:Dieter Seebach、Paola E. Ciceri、Mark Overhand、Bernhard Jaun、Dario Rigo、Lukas Oberer、Ulrich Hommel、Ren� Amstutz、Hans Widmer
DOI:10.1002/hlca.19960790802
日期:1996.12.11
u-(S,S)-β-HAla(αMe)-β-HVal-β-HAla- β-HLeu-OH (22), with a central (2S,3S)-3-amino-2-methylbutanoic-acid residue, confirm the helical structure of such β-peptides (previously discovered in pyridine solution) (Fig.3 and Tables 1–5). The CD spectra of helical β-peptides, the residues of which were prepared by (retentive) Arndt-Eistert homologation of the (S)- or L-α-amino acids, show a trough at 215 nm
可以通过检查模型(图1和2)来定义3个1肽螺旋的稳定性的结构先决条件:3-氨基酸残基的2位和3位侧向非H取代基允许使用螺旋形的,螺旋形的则是禁止的。为了检验这一预测,我们合成了一系列七肽衍生物Boc-(β-HVal-β-HAla-β-HLeu-Xaa-β-HVal-β-HAla-β-HLeu)-OMe 13-22( Xaa =α-或β-氨基酸残基)和带有中央(S)-3-羟基丁酸残基的X-二肽25(Xaa = –OCH(Me)CH 2 C(O)–)(方案1 3)。β-六肽H(-β-HVal-β-HAla-β-HLeu)2 -OH(1)和甲醇的β-六肽甲醇溶液的详细NMR分析(DQF-COSY,HSQC,HMBC,ROESY和TOCSY实验)β-七肽H-β-HVal-β-HAla-β-HLeu-(S,S)-β-HAla(αMe)-β-HVal-β-HAla-β-HLeu-OH(22) (2 S,3