Helical structures of l-Leu-based peptides having chiral six-membered ring amino acids
作者:Tomohiro Umeno、Atsushi Ueda、Makoto Oba、Mitsunobu Doi、Takayuki Hirata、Hiroshi Suemune、Masakazu Tanaka
DOI:10.1016/j.tet.2016.04.040
日期:2016.6
l-Leu-based peptides having chiral six-membered ring amino acids: Boc-l-Leu-l-Leu-[(1R,3R)- or (1S,3R)-Ac6c3M]}n-OMe [n=1 (2), 2 (4), 3 (5)], were synthesized. A conformational analysis using FTIR absorption and NOESY NMR spectra revealed that these hexa- and nonapeptides having (1R,3R)-Ac6c3M or (1S,3R)-Ac6c3M formed helical structures in CDCl3 solution, while that using CD spectra suggested that
升具有手性的六元环氨基酸基于-Leu-肽:将Boc- 升-Leu-升-Leu - [(1 - [R,3 - [R )-或(1小号,3 - [R)-Ac 6 Ç 3M ]}合成了n -OMe [n = 1(2),2(4),3(5)]。使用FTIR吸收和NOESY NMR光谱进行的构象分析表明,这些六肽和九肽具有(1 R,3 R)-Ac 6 c 3M或(1 S,3 R)-Ac 6 c 3M形成螺旋结构在CDCl 3溶液,而使用CD光谱表明,九肽5B具有(1小号,3 - [R)-Ac 6 Ç 3M变得更加右手(P)比九肽α螺旋5A具有(1 - [R,3 R)-Ac 6 c 3M在TFE溶液中。X射线晶体学分析表明,具有(1 S,3 R)-Ac 6 c 3M的六肽4b形成了部分扭曲的右手(P)310- /α螺旋结构处于晶体状态,而具有(1 R,3 R)-Ac 6 c 3M或(1 S,3 R)-Ac