Tanaka Masakazu, Nishimura Shin, Oba Makoto, Demizu Yosuke, Kurihara Masaaki, Suemune Hiroshi
Graduate School of Pharmaceutical Sciences Kyushu University, Fukuoka 812-8582, Japan.
Chemistry. 2003 Jul 7;9(13):3082-90. doi: 10.1002/chem.200204476.
Optically active peptide foldamers Tfa-[(S)-(alphaEt)Leu]-[(S)-(alphaEt)Nva]-Deg-[(S)-(alphaEt)Nle]-OEt (10) and Tfa-[(S)-(alphaEt)Val]-[(S)-(alphaEt)Leu]-[(S)-(alphaEt)Nva]-Deg-[(S)-(alphaEt)Nle]-OEt (11) composed of diverse alpha-ethylated alpha,alpha-disubstituted alpha-amino acids were synthesized. The dominant conformation of these peptides in solution was an unusual, fully extended planar conformation, and that in the crystal state was both right-handed (P) and left-handed (M) 3(10)-helical structures in 10 and a P 3(10)-helical structure in 11, respectively. The preferred planar C(5) conformation of the peptides prepared from chiral alpha-ethylated alpha,alpha-disubstituted alpha-amino acids was drastically different from the 3(10)-helical structure of the peptides prepared from chiral alpha-methylated alpha,alpha-disubstituted alpha-amino acids.
合成了由多种α-乙基化α,α-二取代α-氨基酸组成的旋光性肽折叠体Tfa-[(S)-(αEt)Leu]-[(S)-(αEt)Nva]-Deg-[(S)-(αEt)Nle]-OEt (10)和Tfa-[(S)-(αEt)Val]-[(S)-(αEt)Leu]-[(S)-(αEt)Nva]-Deg-[(S)-(αEt)Nle]-OEt (11)。这些肽在溶液中的主要构象是一种不寻常的完全伸展的平面构象，而在晶体状态下，10中的构象分别是右手(P)和左手(M) 3(10)-螺旋结构，11中的构象是P 3(10)-螺旋结构。由手性α-乙基化α,α-二取代α-氨基酸制备的肽的优选平面C(5)构象与由手性α-甲基化α,α-二取代α-氨基酸制备的肽的3(10)-螺旋结构有很大不同。
