The molecule is a zwitterion derived from heparosan L-iduronic acid. It is the major microspecies at pH 7.3 (according to Marvin v 6.2.0.). It is a tautomer of a heparosan L-iduronic acid.
(2R,3S,4S,5R,6R)-6-[(2R,3S,4R,5R,6S)-5-azaniumyl-4,6-dihydroxy-2-(hydroxymethyl)oxan-3-yl]oxy-3,4,5-trihydroxyoxane-2-carboxylate