一株肺炎克雷伯菌和霍氏假单胞菌的O抗原多糖重复单元的常见主要结构——L-鼠李糖四糖的合成。

Synthesis of an L-rhamnose tetrasaccharide, the common and major structure of the repeating unit of the O-antigenic polysaccharide of a strain of Klebsiella pneumoniae and Pseudomonas holci.

作者信息

Zhang J, Zhu Y, Kong F

机构信息

Research Center for Eco-Environmental Sciences, Academia Sinica, PO Box 2871, Beijing 100085, PR China.

出版信息

Carbohydr Res. 2001 Nov 21;336(3):229-35. doi: 10.1016/s0008-6215(01)00258-0.

DOI:10.1016/s0008-6215(01)00258-0

PMID:11705472

Abstract

A tetrasaccharide, alpha-L-Rhap-(1-->3)-alpha-L-Rhap-(1-->2)-alpha-L-Rhap-(1-->2)-L-Rhap, the common and major structure of the repeating unit of the O-antigenic polysaccharide of a strain of Klebsiella pneumoniae and Pseudomonas holci was synthesized as its methyl and octyl glycosides. Selective 3-O-glycosylation of allyl alpha-L-rhamnopyranoside with 2,3,4-tri-O-acetyl-alpha-L-rhamnopyranosyl trichloroacetimidate gave allyl 2,3,4-tri-O-acetyl-alpha-L-rhamnopyranosyl-(1-->3)-alpha-L-rhamnopyranoside (3). Benzoylation, deallylation, and trichloroacetimidation afforded 2,3,4-tri-O-acetyl-alpha-L-rhamnopyranosyl-(1-->3)-2,4-di-O-benzoyl-alpha-L-rhamnopyranosyl trichloroacetimidate (6). Self condensation of 3,4-di-O-benzoyl-beta-L-rhamnopyranose 1,2-methyl orthoester or 1,2-octyl orthoester gave methyl or octyl 2-O-acetyl-3,4-di-O-benzoyl-alpha-L-rhamnopyranosyl-(1-->2)-3,4-di-O-benzoyl-alpha-L-rhamnopyranoside (16 or 17), and subsequent selective deacetylation gave the disaccharide acceptor (18 or 19). Coupling of 6 with 18 (or 19), followed by deacylation in ammonia-saturated methanol, produced the target tetrasacharide.

摘要

一种四糖，α-L-鼠李糖基-(1→3)-α-L-鼠李糖基-(1→2)-α-L-鼠李糖基-(1→2)-L-鼠李糖，是肺炎克雷伯菌和霍氏假单胞菌菌株O抗原多糖重复单元的常见主要结构，已合成其甲基糖苷和辛基糖苷。烯丙基α-L-鼠李吡喃糖苷与2,3,4-三-O-乙酰基-α-L-鼠李吡喃糖基三氯乙酰亚胺酯进行选择性3-O-糖基化反应，得到烯丙基2,3,4-三-O-乙酰基-α-L-鼠李吡喃糖基-(1→3)-α-L-鼠李吡喃糖苷(3)。进行苯甲酰化、脱烯丙基和三氯乙酰亚胺化反应，得到2,3,4-三-O-乙酰基-α-L-鼠李吡喃糖基-(1→3)-2,4-二-O-苯甲酰基-α-L-鼠李吡喃糖基三氯乙酰亚胺酯(6)。3,4-二-O-苯甲酰基-β-L-鼠李吡喃糖1,2-甲基原酸酯或1,2-辛基原酸酯的自身缩合反应，得到甲基或辛基2-O-乙酰基-3,4-二-O-苯甲酰基-α-L-鼠李吡喃糖基-(1→2)-3,4-二-O-苯甲酰基-α-L-鼠李吡喃糖苷(16或17)，随后进行选择性脱乙酰化反应，得到二糖受体(18或19)。6与18(或19)偶联，然后在氨饱和甲醇中进行脱酰基反应，制得目标四糖。