Complex glycosphingolipids with blood-group A specificity.

The oligosaccharide chains present in blood-group ABH glycoproteins and glycolipids of glandular epithelial tissue exhibit a considerable degree of heterogeneity with respect to length of carbohydrate chains and degree of branching [l-6] . The sizes of the largest blood-group-active oligosaccharide chains from horse gastric mucosa are in the range of 812 sugar residues [7] , whereas those from hog gastric mucosa [I ,3,8] and human cyst fluid [2,4] are closer to 16-l 8 residues or even larger [2] . Glycolipids of unusual complexity with 30-50 sugar residues have recently been isolated from human erythrocyte membrane by Gardas and Koscielak [9,10]. So far the existence of glycolipids of comparable carbohydrate structures in glandular epithelial tissue have not been reported. In this report we describe the isolation and characterization of two blood-group A-active glycolipids, the carbohydrate portions of which consist of 12 and 18 sugar residues.