【文章名】Glycolipids from Sponges. 20. J-Coupling Analysis for Stereochemical Assignments in Furanosides: Structure Elucidation of Vesparioside B, a Glycosphingolipid from the Marine Sponge Spheciospongia vesparia.
Glycolipids from Sponges. 20. J-Coupling Analysis for Stereochemical Assignments in Furanosides: Structure Elucidation of Vesparioside B, a Glycosphingolipid from the Marine Sponge Spheciospongia vesparia.
[摘要]：Reinvestigation of the glycosphingolipid compn. of the marine sponge Spheciospongia vesparia revealed the presence of vesparioside B, a new furanose-rich hexaglycosylated glycosphingolipid that is the most complex glycosphingolipid isolated from a marine sponge to date. The structure of the new compd. was elucidated using extensive 2D NMR studies and chem. degrdn. Particularly useful for structure elucidation of vesparioside B was a quantum mech. computational study, showing that in furanosides a vicinal coupling const. <2.0 Hz (for H-1/H-2 or H-3/H-4) or <3.5 Hz (for H-2/H-3) is a proof of the trans orientation of the relevant protons. This general rule, combined with ROE data, allowed us to elucidate the relative stereochem. (including anomeric configuration) of the three furanose five-membered rings.
