Abstract
Pure tokoronin, mp 275-277°(decomp.), [α]D-13.2°, was obtained in an improved method from the ethanol extracts of rhizomes of Dioscorea tokoro MAKINO and the structure was established as tokorogenin (25D, 5β-spirostane-1β, 2β, 3α-triol)-1-O-α-L-arabinopyranoside (XVII). It represents an additional example of a novel type of spirostanol glycoside in which the sugar moiety is combined with a hydroxyl group other than that at C-3 of the aglycone.
