[4)-beta-D-ManpNAcA-(1->4)-alpha-L-FucpNAc-(1->3)-beta-D-FucpNAc-(1->]n
[4)-beta-d-manpnaca-(1->4)-alpha-l-fucpnac-(1->3)-beta-d-fucpnac-(1->]n
A polysaccharide derivative comprising a trisaccharide repeating unit consisting of <em>N</em>-acetyl-β-<small>D</small>-mannosaminouronic acid, <em>N</em>-acetyl-α-<small>L</small>-fucosamine and <em>N</em>-acetyl-β-<small>D</small>-fucosamine residues linked sequentially (1→4) and (1→3), with the trisaccharide repeats themselves being linked (1→4); corresponds to the de-<em>O</em>-acetylated serotype 5 (CP5) capsular polysaccharide of <em>Staphylococcus aureus</em>.