Structural elucidation of the neutral glycosphingolipids, mono-, di-, tri- and tetraglycosylceramides from the marine crab Erimacrus isenbeckii

The neutral glycosphingolipids, mono-, di-, tri- and tetraglycosylceramides (GL-1, GL-2, GL-3, GL-4a and GL-4b), were identified from whole tissues of the marine crab Erimacrus isenbeckii by successive column chromatography with ion exchange Sephadex (QAE-Sephadex), magnesium silicate (Florisil) and silicic acid (Iatrobeads) resins. Through component analysis, sugar analysis, methylation studies, exoglycosidase cleavage, and various chromatographic and spectrometric techniques, their structures were proposed to be as follows: GL-1, Glcβ1-1Cer; GL-2, Manβ1-4Glcβ1-1Cer; GL-3, Galβ1-3Manβ1-4Glcβ1-1Cer; and GL-4a and GL-4b, Gal3Meα1-4Galβ1-3Manβ1-4Glcβ1-1Cer. The main molecular species of the aliphatic moiety in each purified glycolipid were 18:0, 22:0, 22:1-d14:1 (fatty acid-sphingoid) and 18:0-d16:1 for GL-1; 18:0-d16:1 and 22:1-d14:1, d16:1 for GL-2; 22:1, 24:1-d16:1 for GL-3; 22:1, 24:1-d16:1 for GL-4a; and h22:1, h24:1-d16:1 for GL-4b, respectively. By immunological detection, an arthro-series glycosphingolipid (At3Cer; GlcNAcβ1-3Manβ1-4Glcβ1-1Cer) was also detected as a minor component. The characteristic arthro-series glycosphingolipid has been observed in most animals belonging to the phylum Arthropoda.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2003-2004

This review is the third update of the original review, published in 1999, on the application of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings the topic to the end of 2004. Both fundamental studies and applications are covered. The main topics include methodological developments, matrices, fragmentation of carbohydrates and applications to large polymeric carbohydrates from plants, glycans from glycoproteins and those from various glycolipids. Other topics include the use of MALDI MS to study enzymes related to carbohydrate biosynthesis and degradation, its use in industrial processes, particularly biopharmaceuticals and its use to monitor products of chemical synthesis where glycodendrimers and carbohydrate-protein complexes are highlighted.