Cyclic β-Tetra- and Pentapeptides: Synthesis through On-Resin Cyclization and Conformational Studies by X-Ray, NMR and CD Spectroscopy and Theoretical Calculations
作者:Frank Büttner、Anna S. Norgren、Suode Zhang、Samran Prabpai、Palangpon Kongsaeree、Per I. Arvidsson
DOI:10.1002/chem.200500249
日期:2005.10.21
The solution-phase synthesis of the simplest cyclic beta-tetrapeptide, cyclo(beta-Ala)4 (4), as well as the solid-phase syntheses through side chain anchoring and on-resin cyclization of the cyclic beta3-tetrapeptide cyclo(-beta3hPhe-beta3hLeu-beta3hLys-beta3hGln-) (14) and the first cyclic beta3-pentapeptide cyclo(-beta3hVal-beta3hPhe-beta3hLeu-beta3hLys-beta3hLys-) (19) are reported. Extensive computational
最简单的环状β-四肽环(β-Ala)4(4)的溶液相合成,以及通过环状β3-四肽环(-)的侧链锚固和树脂环化的固相合成报告了beta3hPhe-beta3hLeu-beta3hLys-beta3hGln-)(14)和第一个环状beta3-pentapeptide环(-beta3hVal-beta3hPhe-beta3hLeu-beta3hLys-beta3hLys-)(19)。进行了广泛的计算和光谱学研究,包括X射线和NMR光谱学,以确定这些非天然低聚物在溶液中和固态时的优选构象。没有手性侧链的环β-Ala)4(4)被显示为溶液中快速互换的构象异构体的混合物,而在环-β3-四肽中包含手性侧链会稳定一个主要的构象异构体。另一方面,环状β3-五肽显示更大的构象自由度。非手性环β-Ala)4(4)的X射线结构显示Ci对称的16元环,相邻的C = O和NH原子相对于环平面成对地指向和指向下方。进行