Determination of 3-O- and 4-O-methylated monosaccharide constituents in snail glycans

The N- and O-glycans of Arianta arbustorum, Achatina fulica, Arion lusitanicus and Planorbarius corneus were analysed for their monosaccharide pattern by reversed-phase HPLC after labelling with 2-aminobenzoic acid or 3-methyl-1-phenyl-2-pyrazolin-5-one and by gas chromatography–mass spectrometry. Glucosamine, galactosamine, mannose, galactose, glucose, fucose and xylose were identified. Furthermore, three different methylated sugars were detected: 3-O-methyl-mannose and 3-O-methyl-galactose were confirmed to be a common snail feature; 4-O-methyl-galactose was detected for the first time in snails.