Structural analysis of oligosaccharide-alditols released by reductive β-elimination from oviducal mucins of Rana dalmatina

The O-linked oligosaccharides of the jelly coat surrounding the eggs of Rana dalmatina were released by alkaline borohydride treatment. Low-molecular-mass, monosialyl oligosaccharide-alditols were isolated by anion-exchange chromatography and fractionated by consecutive normal-phase high-performance liquid chromatography on a silica-based alkylamine column. The structures of the oligosaccharide-alditols were determined by 400-MHz 1H-NMR spectroscopy in combination with matrix assisted laser desorption ionization–time of flight analysis. The five structures were identified range in size from trisaccharides to hexasaccharides, possessing a core consisting of Gal(β1–3)GalNAc-ol (core type 1). Novel oligosaccharide-alditols are: