The molecule is a disaccharide that is alpha-D-galactopyranose in which the hydroxy group at position 2 has been converted into the corresponding beta-L-fucopyranoside. It derives from an alpha-D-galactose.
(2S,3S,4R,5S,6R)-2-methyl-6-[(2S,3R,4S,5R,6R)-2,4,5-trihydroxy-6-(hydroxymethyl)oxan-3-yl]oxyoxane-3,4,5-triol