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