The molecule is an amino trisaccharide comprising two alpha-N-acetylneuraminyl residues joined by a (2->8)-linkage and attached in turn by a (2->3)-linkage to beta-D-galactose.
(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]-4-hydroxy-2-[(2R,3R,4S,5S,6R)-2,3,5-trihydroxy-6-(hydroxymethyl)oxan-4-yl]oxyoxane-2-carboxylic acid