The molecule is a polysaccharide derivative with a repeating unit consisting of alpha-D-galactosyl, 2-O-acetyl-beta-L-rhamnosyl, beta-D-glucosyl and N-acetyl-beta-D-galactosaminyl residues linked sequentially (1->3), (1->4) and (1->3), to the galactosyl and N-acetyl-beta-D-galactosaminyl residues of which are attached respectively a beta-D-galactosyl residue and an N-acetyl-alpha-D-glucosaminyl-(1->2)-alpha-L-rhamnosyl disaccharide unit via (1->2) and (1->4) linkages respectively, with all repeating units being linked (1->6). The repeating unit corresponds to that of the capsular polysaccharide of Streptococcus pneumoniae serotype 7F (ST7F).
[(2R,3R,4S,5S,6R)-2-[(2S,3R,4R,5R,6S)-2-[(2R,3R,4R,5R,6R)-5-acetamido-4-[(2R,3R,4R,5S,6R)-5-[(2R,3R,4R,5S,6S)-3-acetyloxy-4-[(2R,3R,4S,5R,6R)-4,5-dihydroxy-6-(hydroxymethyl)-3-[(2S,3R,4S,5R,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxyoxan-2-yl]oxy-5-hydroxy-6-methyloxan-2-yl]oxy-3,4-dihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-6-hydroxy-2-(hydroxymethyl)oxan-3-yl]oxy-4,5-dihydroxy-6-methyloxan-3-yl]oxy-4,5-dihydroxy-6-(hydroxymethyl)oxan-3-yl] acetate