Structures of fucose-containing ceramide pentasaccharides from the plasma of blood group O Le(a-b-) nonsecretors.

A minor, Lec blood-group inactive ceramide pentasaccharide double band fraction has been isolated from the plasma of blood group O Le(a-b-) nonsecretors. The two purified glycolipids were analysed by NMR spectroscopy, mass spectrometry and combined gas chromatography-mass spectrometry. The following structures could be established: GlcNAc(beta 1----3)Gal(beta 1----4)Glc(beta 1----1)Cer (I); Gal(beta 1----4) [Fuc(alpha 1----3)]GlcNAc(beta 1----3)Gal(beta 1----4)Glc(beta 1----1)Cer (II). It must be concluded that at least part of the secretor gene-independent plasmatic H type 2 blood-group activity can be attributed to glycosphingolipid I, whereas substance II, originally detected in cancerous tissue, also occurs in the plasma of healthy individuals.