三肽环化的争议。

Controversy of Peptide Cyclization from Tripeptide.

机构信息

Medical Imaging Research Center, Institute for Radiological Research, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan 333423, Taiwan.

Department of Nephrology and Clinical Poison Center, Chang Gung Memorial Hospital, Taoyuan 333423, Taiwan.

出版信息

Molecules. 2021 Jan 13;26(2):389. doi: 10.3390/molecules26020389.

DOI:10.3390/molecules26020389

PMID:33451079

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC7828492/

Abstract

The present investigation reports an attempt to synthesize naturally occurring α-cyclic tripeptide (Gly-l-Pro-l-Glu) , [(GPE)], previously isolated from the strain of bacteria with marine sponge Three linear precursors, Boc-GPE(OBn), Boc-PE(OBn)G and Boc-E(OBn)GP, were synthesized using a solution phase peptide coupling protocol. Although (GPE) was our original target, all precursors were dimerized and cyclized at 0 °C with high dilution to form corresponding α-cyclic hexapeptide, (GPE(OBn)), which was then converted to cyclic hexapeptide (GPE). Cyclization at higher temperature induced racemization and gave cyclic tripeptide (GPE(OBn). Structure characteristics of the newly synthesized cyclopeptides were determined using H-NMR, C-NMR and high-resolution mass spectrometry. The chemical shift values of carbonyls of and are larger than 170 ppm, indicating the formation of a cyclic hexapeptide.

摘要

本研究报告了一种尝试合成天然存在的α-环三肽（Gly-l-Pro-l-Glu），[（GPE）]，以前从海洋海绵的细菌菌株中分离出来。使用溶液相肽偶联方案合成了三个线性前体 Boc-GPE（OBn）、Boc-PE（OBn）G 和 Boc-E（OBn）GP。尽管（GPE）是我们的原始目标，但所有前体都在 0°C 下以高稀释度二聚化和环化，形成相应的α-环六肽（GPE（OBn）），然后将其转化为环六肽（GPE）。在较高温度下的环化会诱导外消旋化，并得到环三肽（GPE（OBn））。使用 H-NMR、C-NMR 和高分辨率质谱法确定了新合成的环肽的结构特征。和的羰基的化学位移值大于 170 ppm，表明形成了环六肽。