Structure of the Asialyl Oligosaccharide Chains of kappa-Casein Isolated from Ovine Colostrum

Three oligosaccharide alditols, a di (44-63%), tetra (32-46%), and a pentasacchariditol (5-10%) have been isolated from desialylated caseinomacropeptide obtained from kappa-casein of ewe colostrum. The disacchariditol is 2-acetamido-2-deoxy-3-O-(beta-D-galactopyranosyl)galactitol; in the tetrasaccharide this unit is substituted in position 6 of the galactosaminitol moiety by 2-acetamido-2-deoxy-4-O-(beta-D-galactopyranosyl)-beta-D-glucopyranose, while the pentasacchariditol is derived from the tetrasaccharide by addition of a D-galactopyranosyl unit to position 3 of the galactopyranose unit substituting the glucosamine unit.