One-Handed Helical Screw Direction of Homopeptide Foldamer Exclusively Induced by Cyclic α-Amino Acid Side-Chain Chiral Centers
作者:Yosuke Demizu、Mitsunobu Doi、Masaaki Kurihara、Tokumi Maruyama、Hiroshi Suemune、Masakazu Tanaka
DOI:10.1002/chem.201102902
日期:2012.2.20
dissolved in pure water and are more α helical in water than in 2,2,2‐trifluoroethanol solution. The left‐handed (M) helices of the (S,S)‐Ac5cdOMe homochiral homopeptides were exclusively controlled by the side‐chain chiral centers, because the cyclic amino acid (S,S)‐Ac5cdOMe does not have an α‐carbon chiral center but has side‐chain γ‐carbon chiral centers.
手性环状α,α-二取代氨基酸,(3 S,4 S)-和(3 R,4 R)-1-氨基-3,4-(二烷氧基)环戊烷羧酸((S,S)-和(R,R)-Ac 5 c dOR ; R:甲基,甲氧基甲基)是由二甲基L -(+)-或D -(-)-酒石酸酯合成的,它们的同手性均聚物通过溶液相法制备。(S,S)-Ac 5 c dOMe六肽的首选二级结构是左手(M)310螺旋,而(S,S)-Ac 5 c dOMe八肽和十肽的螺旋都是左旋(M)α螺旋,无论是在溶液状态还是在晶体状态。与在2,2,2-三氟乙醇溶液中相比,八肽和十肽可以很好地溶解在纯水中,并且在水中的α螺旋更多。(S,S)-Ac 5 c dOMe同手性同系肽的左旋(M)螺旋仅受侧链手性中心控制,因为环状氨基酸(S,S)-Ac 5 c dOMe 没有α-碳手性中心,但有侧链γ-碳手性中心。