The molecule is a branched amino pentasaccharide consisting of a tetrasaccharide chain of alpha-D-glucose, alpha-L-rhamnose, N-acetyl-beta-D-glucosamine and alpha-L-rhamnose residues linked sequentially (1->4), (1->3) and (1->2), to the non-reducing rhamnose residue of which is also linked (1->3) a further alpha-L-rhamnose residue. Derived from the Shigella liposaccharide O-antigen, it shows antigenic properties. It has a role as an antigen.
N-[(2S,3R,4R,5S,6R)-5-hydroxy-6-(hydroxymethyl)-4-[(2S,3R,4S,5S,6S)-3-hydroxy-6-methyl-5-[(2R,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-4-[(2S,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyoxan-2-yl]oxy-2-[(2R,3R,4R,5R,6S)-2,4,5-trihydroxy-6-methyloxan-3-yl]oxyoxan-3-yl]acetamide