Polyhydroxylated steroidal constituents from the fresh rhizomes of Tupistra yunnanensis

Six new polyhydroxylated steroidal saponins, tupistrosides A-F (1-6), together with nine known steroids, were isolated from the fresh rhizomes of Tupistra yunnanensis. Their structures were elucidated to be (25S)-1β,4β,5β-trihydroxy-spirostane-3β-yl O-α-l-arabinopyranoside (1), 1β,24β-dihydroxy-spirost-5,25(27)-dien-3α-yl O-β-d-glucopyranoside (2), (22S,25S)-1α,2β,3α,5α-tetrahydroxy-furo-spirostane-26-yl O-β-d-glucopyranoside (3), 1β,3α,22 ξ-trihydroxy-furost-5,25(27)-dien-26-yl O-β-d-glucopyranoside (4), 26-O-β-d-glucopyranosyl-1β,22-dihydroxy-furost-5-en-3α-yl O-β-d-glucopyranoside (5) and 22-methoxy-1β,2β,3β,4β,5β,7α-hexahydroxy-furost-25(27)-en-6-one-26-yl O-β-d-glucopyranoside (6), respectively, by means of spectroscopic analysis and the results of acid hydrolysis.