非极性侧链的同手性α-氨基酸的肽可以形成一个1.8 8螺旋。在本文中,我们报道α氨氧基肽的构象研究1,2,3,已经官能化侧链,在这两种非极性和极性溶剂。1 H NMR,XRD和FTIR吸收研究证实了非极性溶剂以及甲醇中均存在八元环分子内氢键(N-O圈)。肽的CD研究1,2,3在不同的溶剂中,表明在甲醇和酸性水性缓冲液中保留了相当程度的螺旋含量。在α-氨氧基肽中引入功能化侧链为设计生物活性肽提供了机会。
revealed that the biased handedness of α N−O turn found in OAcc residue depends on its preceding chiral residue. It was then found that the helicalconformation was destroyed in the case of oligopeptides 6 and 7 [OAA-(OAcc)n, n = 2, 3]. The crystal structure of tripeptide 8 (iPrCO-d-OVal-OAcc-d-OVal-NHiBu) further disclosed the helicalstructure formed by three consecutive homochiral α N−O turns. This study
单体1从非手性的1-(氨氧基)环丙烷羧酸(OACC)和寡肽衍生的2 - 9由手性α氨氧基酸的和如OACC非手性α氨氧基酸的合成和它们的结构特征。八元环分子内氢键,即αN-O圈,在相邻残基之间形成,与它们的手性无关。但是,螺旋的形成是序列依赖性的。在N末端带有手性α-氨基酸(d -OAA)的二肽2和在C末端具有非手性OAcc的二肽优先采用右旋1.8 8螺旋结构,但是二肽3(OAcc- d-OAA)没有。理论计算结果与实验结果吻合良好,表明在OAcc残基中发现的αN-O转弯的偏向性取决于其先前的手性残基。然后发现在寡肽6和7 [OAA-(OAcc)n,n= 2,3]的情况下,螺旋构象被破坏。三肽8(i PrCO- d -OVal-OAcc - d -OVal-NH i的晶体结构Bu)进一步公开了由三个连续的同手性αN-O匝形成的螺旋结构。这项研究发现了非手性氨基氧酸残基(如OAcc单元)是一种
The First Solid-Phase Synthesis of Oligomeric α-Aminooxy Peptides
α-Aminooxy pentapeptides were synthesized on solid support by a stepwise monomer assembly in 40-65% purity of crude products, using the phthaloyl protected monomers.
Synthesis of Optically Active Phthaloyl <scp>d</scp>-Aminooxy Acids from <scp>l</scp>-Amino Acids or <scp>l</scp>-Hydroxy Acids as Building Blocks for the Preparation of Aminooxy Peptides
developed for enantioselective synthesis ot chiral α-aminoxy acids trom aldehydes. In this method, chiral propargylic alcohols are obtained by asymmetric addition of terminal alkynes to aldehydes. The hydroxyl group then converted to aminoxy group via Mitsunobu reaction and oxidative cleavage of the internal carbon-carbon triple bond produce the carboxylic acid group. This represents a convenient approach
Peptides of homochiral α‐aminoxyacids of nonpolar side chains can form a 1.88‐helix. In this paper, we report the conformational studies of α‐aminoxypeptides 1, 2, 3, which have functionalized side chains, in both nonpolar and polar solvents. 1H NMR, XRD, and FTIR absorption studies confirm the presence of the eight‐membered‐ring intramolecular hydrogen bonds (the N‐O turns) in nonpolar solvents
非极性侧链的同手性α-氨基酸的肽可以形成一个1.8 8螺旋。在本文中,我们报道α氨氧基肽的构象研究1,2,3,已经官能化侧链,在这两种非极性和极性溶剂。1 H NMR,XRD和FTIR吸收研究证实了非极性溶剂以及甲醇中均存在八元环分子内氢键(N-O圈)。肽的CD研究1,2,3在不同的溶剂中,表明在甲醇和酸性水性缓冲液中保留了相当程度的螺旋含量。在α-氨氧基肽中引入功能化侧链为设计生物活性肽提供了机会。