The molecule is a trisaccharide that is D-glucopyranose in which the hydroxy groups at positions 3 and 6 have each been converted into the corresponding alpha-D-galactopyranosyl derivative. It derives from a melibiose.
(2R,3R,4S,5R,6S)-2-(hydroxymethyl)-6-[[(2R,3R,4S,5R)-3,5,6-trihydroxy-4-[(2R,3R,4S,5R,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxyoxan-2-yl]methoxy]oxane-3,4,5-triol