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[摘要]：Two new C-22-steroidal lactone glycosides, ypsilactosides A (1) and B (2), were isolated from the EtOH extract of the whole plant of Ypsilandra thibetica. Their structures were established as (3 beta,5 alpha,16 beta,20S)-3,16-dihydroxy-6-oxopregnane-20-carboxylic acid gamma-lactone 3-(beta-D-glucopyranoside) (1) and (3 beta,16 beta)-3,16-dihydroxypregna-5,20-diene-20-carboxylic acid gamma-lactone 3-{O-alpha-L-rhamnopyranosyl-(1 -> 4)-O-alpha-L-rhamnopyranosyl-(1 -> 4)-O-[alpha-L-rhamnopyranosyl-(1 -> 2)]-beta-D-glucopyranoside} (2) on the basis of extensive spectroscopic analyses and chemical degradations. |
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