霍乱弧菌O139 O-PS的一种可用于共轭反应的磷酸化四糖片段的合成。
Synthesis of a Conjugation-Ready, Phosphorylated, Tetrasaccharide Fragment of the O-PS of Vibrio cholerae O139.
作者信息
Soliman Sameh E, Kováč Pavol
机构信息
NIDDK, LBC, Section on Carbohydrates, National Institutes of Health , Bethesda, Maryland 20892-0815, United States.
Department of Chemistry, Faculty of Science, Alexandria University , Alexandria 21321, Egypt.
出版信息
J Org Chem. 2015 Nov 20;80(22):11227-32. doi: 10.1021/acs.joc.5b02105. Epub 2015 Nov 6.
A new pathway to the tetrasaccharide α-Colp-(1→2)-4,6-P-β-d-Galp-(1→3)-[α-Colp-(1→4)]-β-d-GlcpNAc-1-(OCH2CH2)3NH2 has been developed. Glycosylation of 8-azido-3,6-dioxaoctyl 4,6-O-benzylidene-2-deoxy-2-trichloroacetamido-β-d-glucopyranoside with 3,4,6-tri-O-acetyl-2-O-bromoacetyl-α-d-galactopyranosyl bromide afforded the β-linked disaccharide. Debromoacetylation followed by reductive opening of the benzylidene acetal afforded the disaccharide diol acceptor. Halide-assisted glycosylation with 2,4-di-O-benzyl-α-colitosyl bromide gave the 1,2-cis-coupling product. Deacetylation followed by regioselective phosphorylation gave isomeric (R,S)-(P)-4(II),6(II)-cyclic phosphates, which were globally deprotected by one-step catalytic (Pd/C) hydrogenation/hydrogenolysis. The target tetrasaccharide, obtained in high overall yield, is amenable for conjugation to proteins.
已开发出一条通往四糖α - 可洛普糖 - (1→2) - 4,6 - 磷酸 - β - d - 吡喃半乳糖 - (1→3) - [α - 可洛普糖 - (1→4)] - β - d - 吡喃葡萄糖胺 - 1 - (OCH₂CH₂)₃NH₂的新途径。8 - 叠氮基 - 3,6 - 二氧杂辛基4,6 - O - 亚苄基 - 2 - 脱氧 - 2 - 三氯乙酰氨基 - β - d - 吡喃葡萄糖苷与3,4,6 - 三 - O - 乙酰基 - 2 - O - 溴乙酰基 - α - d - 吡喃半乳糖基溴进行糖基化反应，得到β - 连接的二糖。脱溴乙酰化反应，随后亚苄基缩醛进行还原开环，得到二糖二醇受体。用2,4 - 二 - O - 苄基 - α - 可洛糖基溴进行卤化物辅助糖基化反应，得到1,2 - 顺式偶联产物。脱乙酰化反应，随后进行区域选择性磷酸化反应，得到异构体(R,S)-(P)-4(II),6(II)-环磷酸酯，通过一步催化（Pd/C）氢化/氢解反应进行全局脱保护。以高总收率获得的目标四糖适合与蛋白质进行缀合。
Zotero 插件