Novel polyoxygenated spirostanol glycosides from the rhizomes of Helleborus orientalis

The two new polyoxygenated spirostanol bisdesmosides 11 and 2 and the new trisdesmoside 3, named hellebosaponin A (1), B (2), and C (3), respectively, were isolated from the MeOH extract of the rhizomes of Helleborus orientalis. The structures of the new compounds were elucidated as (1beta,3beta,23S,24S)-21-(acetyloxy)-24-[(beta-D-fucopyranosyl)oxy]-3,23-dihydroxyspirosta-5,25(27)-dien-1-yl O-beta-D-apiofuranosyl-(1-->3)-O-(4-O-acetyl-alpha-L-rhamnopyranosyl)-(1-->2)-O-[beta-D-xylopyranosyl-(1-->3)]-alpha-L-arabinopyranoside (1), (1beta,3beta,23S,24S)-21-(acetyloxy)-24-{[O-beta-D-glucopyranosyl-(1-->4)-beta-D-fucopyranosyl]oxy}-3,23-dihydroxyspirosta-5,25(27)-dien-l-yl O-beta-D-apiofuranosyl-(1-->3)-O-(4-O-acetyl-alpha-L-rhamnopyranosyl)-(1-->2)-O-[beta-D-xylopyranosyl-(1-->3)]-alpha-L-arabinopyranoside (2), and (1beta,3beta,23S,24S)-24-[(beta-D-fucopyranosyl)oxy]-21-{[O-beta-D-glucopyranosyl-(1-->2)-beta-D-galactopyranosyl]oxy}-3,23-dihydroxyspirosta-5,25(27)-dien-1-yl O-beta-D-apiofuranosyl-(1-->3)-O-(4-O-acetyl-alpha-L-rhamnopyranosyl)-(1-->2)-O-[beta-D-xylopyranosyl-(1-->3)]-alpha-L-arabinopyranoside (3), respectively, on the basis of detailed spectroscopic studies and chemical evidence.