The molecule is a trisaccharide that is D-galactopyranose in which the hydroxy groups at positions 3 and 4 have been converted to the beta-D-glucopyranosyl and alpha-D-glucopyranosyl derivatives, respectively.
(2R,3R,4S,5S,6R)-2-[(2R,3S,4R,5R)-5,6-dihydroxy-2-(hydroxymethyl)-4-[(2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxyoxan-3-yl]oxy-6-(hydroxymethyl)oxane-3,4,5-triol