The molecule is an organyl group consisting of a D-galactopyranose having an alpha-D-galactopyranosyl residue attached at the 4-position, bound at the 1-position. It is a subsituent group from an alpha-D-Gal-(1->4)-D-Gal.
(2R,3R,4S,5R,6R)-2-[(2R,3R,4R,5S)-4,5-dihydroxy-2-(hydroxymethyl)oxan-3-yl]oxy-6-(hydroxymethyl)oxane-3,4,5-triol