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