Three new steroidal saponins from Fritillaria pallidiflora

Three new steroidal saponins, pallidiflosides A (1), B (2), and C (3), have been isolated from the dry bulbs of Fritillaria pallidiflora Schrenk. Their structures were elucidated as 26-O-β-d-glucopyranosyl-(25R)-furost-5,20(22)-dien-3β,26-diol-3-O-β-d-xylopyranosyl(1 → 4)-[α-l-rhamnopyranosyl(1 → 2)]-β-d-glucopyranoside (1); 26-O-β-d-glucopyranosyl-3β,26-dihydroxyl-20,22-seco-25(R)-furost-5-en-20,22-dione-3-O-α-l-rhamnopyranosyl(1 → 2)-β-d-glucopyranoside (2); and (25R)-spirost-5-ene-3β,17α-diol-3-O-β-d-glucopyranosyl(1 → 4)-β-d-galactopyranoside (3) by spectroscopic techniques and chemical means.