Institute of Clinical and Molecular Virology, University of Erlangen-Nürnberg, D-91054 Erlangen, Germany.
J Pept Sci. 2010 Jan;16(1):65-70. doi: 10.1002/psc.1196.
To prevent aspartimide formation and related side products in Asp-Xaa, particularly Asp-Gly-containing peptides, usually the 2-hydroxy-4-methoxybenzyl (Hmb) backbone amide protection is applied for peptide synthesis according to the Fmoc-protocols. In the present study, the usefulness of the recently proposed acid-labile dicyclopropylmethyl (Dcpm) protectant was analyzed. Despite the significant steric hindrance of this bulky group, N-terminal H-(Dcpm)Gly-peptides are quantitatively acylated by potent acylating agents, and alternatively the dipeptide Fmoc-Asp(OtBu)-(Dcpm)Gly-OH derivative can be used as a building block. In contrast to the Hmb group, Dcpm is inert toward acylations, but is readily removed in the acid deprotection and resin-cleavage step.
为了防止天冬氨酰-氨基酸形成和相关的副产物，特别是含有天冬氨酰-甘氨酸的肽，通常根据 Fmoc 方案应用 2-羟基-4-甲氧基苄基（Hmb）骨架酰胺保护来进行肽合成。在本研究中，分析了最近提出的酸不稳定二环丙甲基（Dcpm）保护剂的有用性。尽管这个大体积基团具有显著的空间位阻，但 N-末端 H-（Dcpm）甘氨酸肽可以被有效酰化试剂定量酰化，并且可以替代地使用二肽 Fmoc-Asp（OtBu）-（Dcpm）甘氨酸-OH 衍生物作为构建块。与 Hmb 基团不同，Dcpm 对酰化反应是惰性的，但在酸脱保护和树脂裂解步骤中很容易被去除。
