[(1aS,1bα,5aα,6aβ)-2α-(β-D-Glucopyranosyloxy)-1a,1b,2,5a,6,6a-hexahydro-1aβ-(hydroxymethyl)oxireno[4,5]cyclopenta[1,2-c]pyran-6α-yl]α-D-galactopyranoside