Five pentapeptides related to gramicidin S, H–Val–Orn(Z)–Leu–d-Phe–Pro–OH, H–Orn(Z)–Leu–d-Phe–Pro–Val–OH, H–Leu–d-Phe–Pro–Val–Orn(Z)–OH, H–d-Phe–Pro–Val–Orn(Z)–Leu–OH, and H–Pro–Val–Orn(Z)–Leu–d-Phe–OH, were cyclized with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and 1-hydroxybenzotriazole. The pentapeptide with a Pro residue at the C-terminal formed predominantly the cyclic dimer (diZ-gramicidin S), while the pentapeptide with an Orn(Z) residue at the C-terminal produced exclusively the cyclic monomer (Z-semigramicidin S). The reaction mode of those pentapeptides was correlated with their CD spectra.
与
短杆菌肽 S 相关的五肽,H–Val–Orn(Z)–Leu–d-Phe–Pro–OH、H–Orn(Z)–Leu–d-Phe–Pro–Val–OH、H–Leu–d -Phe–Pro–Val–Orn(Z)–OH、H–d-Phe–Pro–Val–Orn(Z)–Leu–OH 和 H–Pro–Val–Orn(Z)–Leu–d-Phe -OH,用1-乙基-3-(3-二甲基
氨基丙基)碳二
亚胺盐酸盐和
1-羟基苯并三唑环化。 C端带有Pro残基的五肽主要形成环状二聚体(二Z-
短杆菌肽S),而C端带有Orn(Z)残基的五肽仅产生环状单体(Z-半
短杆菌肽S)。这些五肽的反应模式与其圆二色光谱相关。