Zwitterionic Polysaccharides of Shigella sonnei : Synthetic Study toward a Ready-for-Oligomerization Building Block Made of Two Rare Amino Sugars
Zwitterionic Polysaccharides of Shigella sonnei : Synthetic Study toward a Ready-for-Oligomerization Building Block Made of Two Rare Amino Sugars
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DOI：
10.1055/s-0037-1609719
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发表时间：
2018-11-01
影响因子：
2.6
通讯作者：
Mulard, Laurence A.
中科院分区：
文献类型：
--
作者：
Pfister, Helene B.;Paoletti, Julie;Mulard, Laurence A.
志贺氏菌病是一种由革兰氏阴性菌志贺氏菌引起的地方性腹泻病。最暴露的宋内志贺氏菌多糖显示出由两种稀有氨基糖组成的两性离子二糖重复单元 (AB)：[4)-- l -Alt p NAcA-(13)-- d -Fuc p NAc4N-(1]。报道了一种可低聚化的 AB 二糖的原始合成。目标正交保护二糖是由 l-葡萄糖和四- O-乙酰基-- d 合成的具有挑战性的引入 4 (B)-叠氮基掩蔽 AAT 残基的氨基部分是在二糖阶段通过两步程序进行的（三氟甲磺酸化，然后用 NaN (3) 进行亲核置换），采用糖基化后氧化策略来获得阿曲糖酸部分。
Shigellosis is an endemic diarrheal disease caused by Gram negative bacteria named Shigella . The most exposed polysaccharides of Shigella sonnei display a zwitterionic disaccharide repeating unit (AB) made of two rare amino sugars: [4)-- l -Alt p NAcA-(13)-- d -Fuc p NAc4N-(1]. An original synthesis of a ready-for-oligomerization AB disaccharide is reported. The targeted orthogonally protected disaccharide was synthesized from l -glucose and tetra- O -acetyl-- d -glucosamine. The challenging introduction of the 4 (B) -azido group masking the amino moiety of the AAT residue was performed at the disaccharide stage by a two-step procedure (triflation followed by nucleophilic displacement with NaN (3) ). A post-glycosylation oxidation strategy was employed to access the altruronate moiety.