The molecule is a linear amino tetrasaccharide comprising two N-acetyl-alpha-neuraminyl residues, a beta-D-galactose residue and (at the reducing end) an N-acetyl-D-glucosamine residue, linked sequentially (2->8), (2->3) and (1->4). It is a glucosamine oligosaccharide and an amino tetrasaccharide.
(2S,4S,5R,6R)-5-acetamido-6-[(1S,2R)-2-[(2S,4S,5R,6R)-5-acetamido-2-carboxy-4-hydroxy-6-[(1R,2R)-1,2,3-trihydroxypropyl]oxan-2-yl]oxy-1,3-dihydroxypropyl]-2-[(2S,3R,4S,5S,6R)-2-[(2R,3S,4R,5R)-5-acetamido-4,6-dihydroxy-2-(hydroxymethyl)oxan-3-yl]oxy-3,5-dihydroxy-6-(hydroxymethyl)oxan-4-yl]oxy-4-hydroxyoxane-2-carboxylic acid