Synthetic Studies on Glycosphingolipids from Protostomia Phyla: Synthesis of Amphoteric Glycolipid Analogues from the Porcine Nematode, Ascaris suum.
作者:Isao Ohtsuka、Noriyasu Hada、Hiroko Ohtaka、Mutsumi Sugita、Tadahiro Takeda
DOI:10.1248/cpb.50.600
日期:——
A novel amphoteric glycosphingolipid, cholinephosphoryl-(→6)-β-D-GlcpNAc-(1→3)-β-D-Manp-(1→4)-β-D-Glcp-(1→)-Cer, isolated from the porcine parasitic nematode, Ascaris suum, may be expected to be involved in host-parasite interactions. This glycosphingolipid analogue containing octyl residue in place of ceramide was synthesized as follows: The key reaction of this synthetic procedure is the formation of a intramolecular aglycon delivery (IAD) approach for β-selective mannosylation. Then, a coupling of phosphocholine group at the position C-6″ of 16 was attempted using 2-chloro-2-oxo-1,3,2-dioxaphospholane, followed by reaction of the resulting cyclic phosphate intermediate with anhydrous trimethylamine to give 17. Subsequent debenzylation and debenzylidenation afforded target compound (2).
从猪寄生线虫猪蛔虫(Ascaris suum)中分离得到一种新型两性糖神经鞘脂——胆碱磷酸基-(→6)-β-D-GlcpNAc-(1→3)-β-D-Manp-(1→4)-β-D-Glcp-(1→)-神经酰胺,可能参与宿主-寄生虫相互作用。含辛基残基替代神经酰胺的类似糖神经鞰脂合成步骤如下:该合成过程的关键反应是形成内酰胺输送(IAD)途径以实现β-选择性甘露糖化。然后,在16的C-6″位上尝试进行磷酸胆碱基的耦合,使用2-氯-2-氧-1,3,2-二氧磷杂环戊烷,随后与无水三甲胺反应,得到环状磷酸酯中间体17。接着经过去苄基化和去苄叉基化得到目标化合物(2)。