The molecule is a branched amino tetrasaccharide comprised of a trisaccharide chain of N-acetyl-alpha-neuraminic acid, beta-D-galactose and N-acetyl-beta-D-glucosamine residues linked sequentially (2->3) and (1->4), to the galactose residue of which is also linked (1->4) an N-acetyl-beta-L-galactosamine residue. It has a role as an epitope. It is an amino tetrasaccharide, a glucosamine oligosaccharide and a galactosamine oligosaccharide.
(2S,4S,5R,6R)-5-acetamido-2-[(2S,3R,4R,5S,6R)-5-[(2S,3R,4R,5R,6R)-3-acetamido-4,5-dihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-2-[(2R,3S,4R,5R,6R)-5-acetamido-4,6-dihydroxy-2-(hydroxymethyl)oxan-3-yl]oxy-3-hydroxy-6-(hydroxymethyl)oxan-4-yl]oxy-4-hydroxy-6-[(1R,2R)-1,2,3-trihydroxypropyl]oxane-2-carboxylic acid