Studies on the Constituents of Ophiopogonis Tuber. IV. On the Structures of Ophiopogonin A, B', C, C', and D'

Ophiopogonin A, B', C, C', and D', the minor oligosides of Ophiopogonis tuber (tuber of Ophiopogon japonicus KER-GAWLER var. genuinus MAXIM.), have been isolated. The structures of these oligosides have been established as follows : ophiopogonin A (III) : ruscogenin 1-O-[(3-O-acetyl)-α-L-rhamnopyranosyl (1→2)]-β-D-fucopyranoside, ophiopogonin B'(IV) : diosgenin 3-O-[(4-O-acetyl)-α-L-rhamnopyranosyl (1→2)] [β-D-xylopyranosyl (1→3)]-β-D-glucopyranoside, ophiopogonin C (V) : mono-O-acetylophiopogonin D, ophiopogonin C'(VI) : diosgenin 3-O-α-L-rhamnopyranosyl (1→2)-β-D-glucopyranoside (=prosapogenin A of dioscin), ophiopogonin D'(VII) : diosgenin 3-O-[α-L-rhamnopyranosyl-(1→2)] [β-D-xylopyranosyl (1→3)]-β-D-glucopyranoside.