Structure of some oligosaccharides derived from rat-intestinal glycoproteins

Glycoproteins derived from intestinal mucus were isolated by phenol-water extraction of feces from germ-free rats. The water-soluble glycoproteins were subjected to alkaline-borohydride degradation, and three different oligosaccharide alditols were isolated. The structures of thse were determined by using methylation analysis and n.m.r. spectroscopy as the principal methods. One disaccharide alditol and one trisaccharide alditol were characterised as beta-D-GlcNAcp-(1 leads to 3)-D-GalNAcol and alpha-L-Fucp-(1 leads to 2)-beta-D-Galp-(1 leads to 3)-D-GalNAcol. The third oligosaccharide alditol was a blood-group A-active tetrasaccharide alditol for which the structure alpha-D-GalNAcp-(1 leads to 3)-[alpha-L-Fucp-(1 leads to 2)]-beta-D-Galp-(1 leads to 3)-D-GalNAcol is proposed.