Synthesis of a common trisaccharide fragment of glycoforms of the outer core region of the Pseudomonas aeruginosa lipopolysaccharide
Synthesis of a common trisaccharide fragment of glycoforms of the outer core region of the Pseudomonas aeruginosa lipopolysaccharide
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DOI：
10.1016/j.tetlet.2006.03.045
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发表时间：
2006-05-22
影响因子：
1.8
通讯作者：
Nifantiev, Nikolay E.
中科院分区：
文献类型：
--
作者：
Komarova, Bozhena S.;Tsvetkov, Yury E.;Nifantiev, Nikolay E.
首次合成了铜绿假单胞菌脂多糖外核区糖型的常见三糖。通过对 β-(1 -> 3) 连接的 6-O-苄基-2-叠氮基-2-脱氧-3-O-(2,3,4,6-四-O-乙酰基-β-D-吡喃葡萄糖基)-α-D-吡喃半乳糖苷进行高效 α-(1 -> 4)-葡萄糖基化，制备了完全受保护的三糖前体。相反，另一种糖基化序列涉及 α-(1 -> 4)-连接的 Glc-GalN(3) 单元的 β-葡萄糖基化，但不会产生目标三糖主链。受保护的三糖前体进一步进行O-脱乙酰、叠氮基还原和脱苄基，得到相应的三糖胺。后一种结构用于合成一系列在GalN的C-2氨基上带有乙酰基、L-丙氨酸或N-乙酰化L-丙氨酸残基的三糖。 (c) 2006 Elsevier Ltd. 保留所有权利。
The first synthesis of the common trisaccharide of glycoforms of the outer core region of the Pseudomonas aeruginosa lipopolysaccharide is reported. A fully protected trisaccharide precursor was prepared via a highly efficient alpha-(1 -> 4)-glucosylation of a beta-(1 -> 3)-linked 6-O-benzyl-2-azido-2-deoxy-3-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-alpha-D-galactopyranoside. In contrast, an alternative sequence of glycosylations, which involves beta-glucosylation of an alpha-(1 -> 4)-linked Glc-GalN(3) unit, did not lead to the target trisaccharide backbone. Further O-deacetylation, azido group reduction and debenzylation of the protected trisaccharide precursor gave the corresponding trisaccharide amine. The latter structure was used in the synthesis of a series of trisaccharides bearing an acetyl group, an L-alanine or an N-acetylated L-alanine residue on its amino group at C-2 of GalN. (c) 2006 Elsevier Ltd. All rights reserved.