The molecule is an amino disaccharide consisting of two alpha(2->9)-linked sialic acid units; corresponds to the repeating unit in the group C polysaccharide of Neisseria meningitidis (MenC).
(2R,4S,5R,6R)-5-acetamido-6-[(1R,2R)-3-[(2R,4S,5R,6R)-5-acetamido-2-carboxy-4-hydroxy-6-[(1R,2R)-1,2,3-trihydroxypropyl]oxan-2-yl]oxy-1,2-dihydroxypropyl]-2,4-dihydroxyoxane-2-carboxylic acid