两种异构五糖（丁香假单胞菌丁香致病变种NCPPB 3364T和NCPPB 3365脂多糖中的O重复单元）的简洁合成。

A concise synthesis of two isomeric pentasaccharides, the O repeat units from the lipopolysaccharides of P. syringae pv. porri NCPPB 3364T and NCPPB 3365.

作者信息

Ma Zuchao, Zhang Jianjun, Kong Fanzuo

机构信息

Research Center for Eco-Environmental Sciences, Academia Sinica, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.

出版信息

Carbohydr Res. 2004 Jan 2;339(1):43-9. doi: 10.1016/j.carres.2003.09.014.

DOI:10.1016/j.carres.2003.09.014

PMID:14659670

Abstract

A concise synthesis of two isomeric pentasaccharides, alpha-L-Rhap-(1-->2)-alpha-L-Rhap-(1-->3)-alpha-L-Rhap-(1-->3)-[beta-D-GlcpNAc-(1-->2)]-alpha-L-Rhap (A) and alpha-L-Rhap-(1-->2)-alpha-L-Rhap-(1-->3)-[beta-D-GlcpNAc-(1-->2)]-alpha-L-Rhap-(1-->3)-alpha-L-Rhap (B), the O repeats from the lipopolysaccharides of Pseudonomonas syringae pv. porri NCPPB 3364T and 3365 was achieved via assembly of the building blocks, allyl 3,4-di-O-benzoyl-alpha-L-rhamnopyranoside (1), 2,3,4-tri-O-benzoyl-alpha-L-rhamnopyranosyl trichloroacetimidate (2), allyl 4-O-benzoyl-3-O-chloroacetyl-alpha-L-rhamnopyranoside (6), 3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-beta-D-glucopyranosyl trichloroacetimidate (7), and allyl 2,4-di-O-benzoyl-alpha-L-rhamnopyranoside (10). Coupling of 1 with 2 followed by deallylation and trichloroacetimidate formation gave the disaccharide donor 5, while condensation of 6 with 7, followed by dechloroacetylation, offered the disaccharide acceptor 9. Then, 5 was coupled with 10 to obtain the trisaccharide 11, and subsequent deallylation and trichloroacetimidate formation furnished the trisaccharide donor 13. Coupling of 9 with 13, followed by deprotection, afforded pentasaccharide 19, while condensation of 9 with 5, followed by deallylation and trichloroacetimidate formation, gave the tetrasaccharide donor 16, whose coupling with 10 and subsequent deprotection yielded another pentasaccharide 22.

摘要

通过组装结构单元烯丙基3,4-二-O-苯甲酰基-α-L-鼠李吡喃糖苷（1）、2,3,4-三-O-苯甲酰基-α-L-鼠李吡喃糖基三氯乙酰亚胺酯（2）、烯丙基4-O-苯甲酰基-3-O-氯乙酰基-α-L-鼠李吡喃糖苷（6）、3,4,6-三-O-乙酰基-2-脱氧-2-邻苯二甲酰亚胺基-β-D-吡喃葡萄糖基三氯乙酰亚胺酯（7）和烯丙基2,4-二-O-苯甲酰基-α-L-鼠李吡喃糖苷（10），实现了两种异构五糖α-L-鼠李糖基-(1→2)-α-L-鼠李糖基-(1→3)-α-L-鼠李糖基-(1→3)-[β-D-葡萄糖胺基-(1→2)]-α-L-鼠李糖（A）和α-L-鼠李糖基-(1→2)-α-L-鼠李糖基-(1→3)-[β-D-葡萄糖胺基-(1→2)]-α-L-鼠李糖基-(1→3)-α-L-鼠李糖（B）的简洁合成，这两种五糖是丁香假单胞菌丁香致病变种pv. porri NCPPB 3364T和3365脂多糖中的O重复单元。1与2偶联，随后脱烯丙基并形成三氯乙酰亚胺酯，得到二糖供体5，而6与7缩合，随后脱氯乙酰化，得到二糖受体9。然后，5与10偶联得到三糖11，随后脱烯丙基并形成三氯乙酰亚胺酯，得到三糖供体13。9与13偶联，随后脱保护，得到五糖19，而9与5缩合，随后脱烯丙基并形成三氯乙酰亚胺酯，得到四糖供体16，其与10偶联并随后脱保护得到另一种五糖22。