Steroidal saponins from the rhizomes of Polygonatum sibiricum.

Four new steroidal saponins, named neosibiricosides A−D (1−4), were isolated from the rhizomes of Polygonatum sibiricum, along with two known spirostanol glycosides. The structures of the new glycosides were elucidated by spectroscopic methods and acid hydrolysis as (23S,24R,25R)-1-O-acetylspirost-5-ene-1β,3β,23,24-tetrol 3-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl-(1→4)-β-d-fucopyranoside (1), (25S)-1-O-acetylspirost-5-ene-1β,3β-diol 3-O-β-d-glucopyranosyl-(1→2)-[β-d-xylopyranosyl-(1→3)]-β-d-glucopyranosyl-(1→4)-β-d-galactopyranoside (2), (25S)-spirost-5-en-3β-ol 3-O-β-d-glucopyranosyl-(1→2)-[β-d-xylopyranosyl-(1→3)]-β-d-glucopyranosyl-(1→4)-2-O-acetyl-β-d-galactopyranoside (3), and (25R,S)-spirost-5-en-3β-ol 3-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl-(1→4)-β-d-galactopyranoside (4). The cytotoxic activity of the isolated compounds was evaluated with human MCF-7 breast cancer cells.