A NOVEL DIFUCOSYLATED NEUTRAL GLYCOSPHINGOLIPID FROM THE EGGS OF THE SEA-URCHIN, HEMICENTROTUS-PULCHERRIMUS .2. STRUCTURAL DETERMINATION BY 2-DIMENSIONAL NMR

A novel fucosylglycolipid from the eggs of the sea urchin, Hemicentrotus pulcherrimus, was determined by using two-dimensional NMR methods. Subspectra extraction by the homonuclear Hartmann-Hahn method was useful for identification of the individual sugar components. The homonuclear Hartmann-Hahn and double-quantum-filtered correlated spectra were analyzed to establish the assignments of sugar proton resonances. On the basis of the resonance assignments, the linkages of the individual sugar components were determined to be as follows. GalNAc-beta-1-4GlcNAc-beta-1-4Glc-beta-1-1Cer 3 3 Fuc-alpha-1 Fuc-alpha-1 This glycolipid contains a novel skeletal structure with the linkages of GalNAc-beta-1-4GlcNAc-beta-1-4Glc-beta. We also observed that 2-hydroxylation of the fatty acids induced appreciable chemical shift changes of the proton resonances of the phytosphingosine moiety as well as the anomeric proton resonance of the reducing terminal glucose.