The molecule is a trisaccharide consisting of alpha-D-galactopyranose, beta-D-galactopyranose and L-fucopyranose residues joined in sequence by (1->4) glycosidic bonds. It derives from an alpha-D-Galp-(1->4)-beta-D-Galp and a L-fucopyranose.
(3S,4S,5S,6S)-5-[(2S,3R,4R,5R,6R)-3,4-dihydroxy-6-(hydroxymethyl)-5-[(2R,3R,4S,5R,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxyoxan-2-yl]oxy-6-methyloxane-2,3,4-triol