The molecule is a trisaccharide consisting that is beta-lactose in which the hydroxy group at the 3' position has been converted into the corresponding alpha-L-fucopyranosyl derivative. It derives from a beta-lactose and an alpha-L-fucose.
(2S,3S,4R,5S,6S)-2-[(2R,3S,4S,5R,6S)-3,5-dihydroxy-2-(hydroxymethyl)-6-[(2R,3S,4R,5R,6R)-4,5,6-trihydroxy-2-(hydroxymethyl)oxan-3-yl]oxyoxan-4-yl]oxy-6-methyloxane-3,4,5-triol