The molecule is a polyanionic polymer obtained by deprotonation of the carboxy groups of [(1->2)-alpha-L-rhamnosyl-(1->4)-alpha-D-galacturonosyl]n; major species at pH 7.3. It is a polyanionic polymer and a carbohydrate acid anion.
(2S,3R,4R,5R,6S)-4,5,6-trihydroxy-3-[(2S,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxyoxane-2-carboxylate