Ishiwata Akihiro, Ohta Soichi, Ito Yukishige
RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan.
Carbohydr Res. 2006 Jul 24;341(10):1557-73. doi: 10.1016/j.carres.2006.03.011. Epub 2006 Apr 17.
It has been shown that certain prokaryotes, such as Campylobacter jejuni, have asparagine (Asn)-linked glycoproteins. However, the structures of their glycans are distinct from those of eukaryotic origin. They consist of a bacillosamine residue linked to Asn, an alpha-(1-->4)-GalpNAc repeat, and a branching beta-Glcp residue. In this paper, we describe a strategy for the stereoselective construction of the alpha-(1-->4)-GalpNAc repeat of a C. jejuni N-glycan, utilizing a pentafluoropropionyl (PFP) group as a temporary protective group of the C-4 OH group of the GalpN donor. The strategy was applied to the synthesis of the hexasaccharide alpha-GalpNAc-(1-->4)-alpha-GalpNAc-(1-->4)-[beta-Glcp-(1-->3)]-alpha-GalpNAc(1-->4)-alpha-GalpNAc-(1-->4)-GalpNAc.
已表明某些原核生物，如空肠弯曲菌，具有天冬酰胺（Asn）连接的糖蛋白。然而，它们聚糖的结构与真核生物来源的聚糖结构不同。它们由连接到Asn的一个杆菌胺残基、一个α-(1→4)-GalpNAc重复序列和一个分支的β-Glcp残基组成。在本文中，我们描述了一种用于立体选择性构建空肠弯曲菌N-聚糖的α-(1→4)-GalpNAc重复序列的策略，利用五氟丙酰基（PFP）基团作为GalpN供体C-4 OH基团的临时保护基团。该策略应用于六糖α-GalpNAc-(1→4)-α-GalpNAc-(1→4)-[β-Glcp-(1→3)]-α-GalpNAc(1→4)-α-GalpNAc-(1→4)-GalpNAc的合成。
