The molecule is a nucleotide-sugar oxoanion obtained by deprotonation of the diphosphate OH groups of GDP-D-mannuronic acid; major species at pH 7.3. It is a conjugate base of a GDP-D-mannuronic acid.
(2S,3S,4S,5S)-6-[[[(2R,3S,4R,5R)-5-(2-amino-6-oxo-1H-purin-9-yl)-3,4-dihydroxyoxolan-2-yl]methoxy-oxidophosphoryl]oxy-oxidophosphoryl]oxy-3,4,5-trihydroxyoxane-2-carboxylate