The molecule is a doubly-charged nucleotide-sugar oxoanion obtained via deprotonation of the diphosphate OH groups of UDP-N-acetyl-L-fucosamine; major species at pH 7.3. It is a conjugate base of an UDP-N-acetyl-beta-L-fucosamine.
[(2R,3S,4S,5S,6S)-3-acetamido-4,5-dihydroxy-6-methyloxan-2-yl] [[(2R,3S,4R,5R)-5-(2,4-dioxopyrimidin-1-yl)-3,4-dihydroxyoxolan-2-yl]methoxy-oxidophosphoryl] phosphate