The molecule is a glycosylgalactose consisting of alpha-D-glucopyranose and D-galactopyranose joined in sequence by a (1->4) glycosidic bond. It derives from an alpha-D-glucose and a D-galactose.
(2R,3S,4S,5R,6R)-2-(hydroxymethyl)-6-[(2R,3R,4R,5R)-4,5,6-trihydroxy-2-(hydroxymethyl)oxan-3-yl]oxyoxane-3,4,5-triol