it was shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis , hydrolysis , methylation , and both one- and two-dimensional 1h and 13c nuclear magnetic resonance studies to be an s-type lipopolysaccharide , which could be cleaved to yield a lipid a and an o-chain polysaccharide identified as a high molecular weight branched polymer of a tetrasaccharide repeating unit having the structure : ( formula : see text ) .
C0023810
lipopolysaccharide
C0023767
lipid a