Synthesis of a nonasaccharide with two lewis x trisaccharides anchored onto a branched trimannoside
摘要:
Double condensation of phenyl 3,4,6-tri-O-benzyl-2-O-[6-O-benzyl-2-deoxy-2-phthalimido-4-O-(2 ,3,4,6-tetra-O-benzoyl-beta-D-galactopyranosyl)-3-O-(2,3,4-tri-O-benzyl-alpha-L-fucopyranosyl)-beta-D-glucopyranosyl]- 1-thio-alpha-D-mannopyranoside 31 with methyl 2,4-di-O-benzyl-beta-D-mannopyranoside 35, in the presence of N-iodosuccinimide/trifluoromethane-sulfonic acid, gave the protected nonasaccharide 36 in 60% yield. Conventional deprotection gave the nonasaccharide 1, in which two Lewis x trisaccharides are anchored onto a branched trimannoside.
Chemical synthesis of a hexasaccharide comprising the Lewisx determinant linked β-(1 → 6) to a linear trimannosyl core and the precursor pentasaccharide lacking fucose
作者:Rakesh K. Jain、Khushi L. Matta
DOI:10.1016/0008-6215(95)00376-2
日期:1996.2
D-mannopyranosyl)-(1-->6)-2,3,4-tri-O-benzyl- alpha-D- mannopyranoside (12) in the presence of NIS-triflic acid to give, after removal of the chloroacetyl group, the key intermediate, benzyl O-(2,3,4-tri-O-acetyl-alpha-D-mannopyranosyl)-(1-->6)-O-(2,3,4-tri-O-ben zyl- beta-D-mannopyranosyl)-(1-->6)-2,3,4-tri-O-benzyl-alpha-D-mannopyranosid e (14). A similar condensation of 6 and 7 with acceptor 14
the so-called LewisX determinant. A triethyleneglycol spacer was used in order to introduce the mobility required for the study of single carbohydrate−carbohydrate interactions. Three phytyl chains increase the hydrophobicity of the lipid moiety compared to the natural ceramide glycolipid 1. These glycolipids display a liquid-expanded behaviour with a high compressibility in monolayer studies. These
制备了两种高度疏水的路易斯 X 糖脂 2 和 3。糖缀合物 2 以下列方式构建:季戊四醇用作分配器,其上的三个外消旋植醇疏水链和一个三甘醇间隔基用五糖 Gal (β 1-4)[Fuc (α 1-3)] GlcNAc β-糖基化(β 1-3) Gal (β 1-4) Glc 被锚定。糖缀合物 3 以类似的方式构建,糖部分是三糖 Gal (β 1-4)[Fuc (α 1-3)] GlcNAc,即所谓的 Lewis X 决定簇。使用三甘醇间隔物以引入研究单一碳水化合物-碳水化合物相互作用所需的流动性。与天然神经酰胺糖脂 1 相比,三个植基链增加了脂质部分的疏水性。这些糖脂在单层研究中显示出具有高压缩性的液体膨胀行为。这些与在水中的低溶解度相关的特性使它们成为研究两个 Lewis X 功能化囊泡之间相互作用的良好候选者。
Chemical synthesis of a core 2 branched pentasaccharide containing a carboxylate group
作者:Jie Xia、James L. Alderfer、Khushi L. Matta
DOI:10.1016/s0960-894x(00)00497-2
日期:2000.11
Design and synthesis of a carboxylate-containing pentasaccahride 1 with the Gal beta>(*) over bar * (1-4) (Fuc alpha1-3)GlcNAc beta>(*) over bar *( 1-6)3-[1-carboxymethyl]-Gal beta>(*) over bar * (1-3)} GalNAc alpha -OMe sequence, which is obtained through regioselective coupling of the 6-OH of a novel acceptor 9 with Lewis(x) donor 10 catalyzed by NIS-TfOH are described. (C) 2000 Elsevier Science Ltd. All rights reserved.