Structural analysis of hexa to dodecaoligosaccharide-alditols released by reductive beta-elimination from oviducal mucins of Bufo bufo.

ABSTRACT

Hexa to dodecasaccharide-alditols of the jelly coat surrounding the eggs of the toad Bufo bufo were studied by methylation analysis, MALDI-TOF mass spectrometry, and H-NMR spectroscopy. These highly species-specific carbohydrate chains exhibit new structural features, such as the elongation of the blood group A determinant with an external alpha-1,3-linked galactose unit, or ramification belonging from a fucosylated galactose. The most representative oligosaccharide-alditol of the series was defined as following [structure in text]. Since the jellies surrounding amphibian eggs are involved in egg-sperm interactions, these structural investigations can provide biochemical support for exploring the fertilization process.