Novel Polyoxygenated Spirostanol Glycosides from the Rhizomes of Helleborus orientalis

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 (1 β ,3 β ,23 S ,24 S )‐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 ), (1 β ,3 β ,23 S ,24 S )‐ 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 (1 β ,3 β ,23 S ,24 S )‐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.