The molecule is a polysaccharide derivative comprised of a [2)-alpha-L-Rhap(III)-(1->2)-alpha-L-Rhap(II)-(1->3)-alpha-L-Rhap(I)-(1->3)-beta-D-GlcpNAc-(1->] tetrasaccharide repeat modified by the (1->4) linkage of an alpha-D-glucosyl group to the Rha(I) residue and by addition of acetyl groups to 60% of the O-6 positions of the GlcNAc residue and to either O-3 or O-4 of many of the Rha(III) residues (60% to O-3; 25% to O-4). The structure provided is representative of that in Shigella flexneri serotype 2a and shows the most common repeating unit. It has a role as an antigen.
[(2R,3S,4R,5R,6R)-5-acetamido-4-[(2S,3R,4S,5S,6S)-4-[(2S,3R,4R,5R,6S)-3-[(2S,3R,4R,5S,6S)-4-acetyloxy-3,5-dihydroxy-6-methyloxan-2-yl]oxy-4,5-dihydroxy-6-methyloxan-2-yl]oxy-3-hydroxy-6-methyl-5-[(2R,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxyoxan-2-yl]oxy-3,6-dihydroxyoxan-2-yl]methyl acetate