Novel Polyoxygenated Spirostanol Glycosides from the Rhizomes of Helleborus orientalis

Abstract The two new polyoxygenated spirostanol bisdesmosides 1 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 (1β,3β,23S,24S)‐21‐(acetyloxy)‐24‐[(β‐D‐fucopyranosyl)oxy]‐3,23‐dihydroxyspirosta‐5,25(27)‐dien‐1‐yl O‐β‐D‐apiofuranosyl‐(1→3)‐O‐(4‐O‐acetyl‐α‐L‐rhamnopyranosyl)‐(1→2)‐O‐[β‐D‐xylopyranosyl‐(1→3)]‐α‐L‐arabinopyranoside (1), (1β,3β,23S,24S)‐ 21‐(acetyloxy)‐24‐{[O‐β‐D‐glucopyranosyl‐(1→4)‐β‐D‐fucopyranosyl]oxy}‐3,23‐dihydroxyspirosta‐5,25(27)‐dien‐1‐yl O‐β‐D‐apiofuranosyl‐(1→3)‐O‐(4‐O‐acetyl‐α‐L‐rhamnopyranosyl)‐(1→2)‐O‐[β‐D‐xylopyranosyl‐(1→3)]‐ α‐L‐arabinopyranoside (2), and (1β,3β,23S,24S)‐24‐[(β‐D‐fucopyranosyl)oxy]‐21‐{[O‐β‐D‐glucopyranosyl‐(1→2)‐β‐D‐galactopyranosyl]oxy}‐3,23‐dihydroxyspirosta‐5,25(27)‐dien‐1‐yl O‐β‐D‐apiofuranosyl‐(1→3)‐O‐(4‐O‐acetyl‐α‐L‐rhamnopyranosyl)‐(1→2)‐O‐[β‐D‐xylopyranosyl‐(1→3)]‐α‐L‐arabinopyranoside (3), respectively, on the basis of detailed spectroscopic studies and chemical evidence.