Studies on the Chinese crude drug "Shoma." VIII. Two new triterpenol bisdesmosides, 3-arabinosyl-24-O-acetylhydroshengmanol 15-glucoside and 3-xylosyl-24-O-acetylhydroshengmanol 15-glucoside, from Cimicifuga dahurica.

Two new triterpenol glycosides were isolated from the rhizomes of Cimicifuga dahurica (Ranunculaceae): 3-arabinosyl-24-O-acetylhydroshengmanol 15-glucoside (1), C43H70O16, mp 222-223 degrees C, [alpha]D +21.0 degrees and 3-xylosyl-24-O-acetylhydroshengmanol 15-glucoside (2), C43H70O16, mp 208-210 degrees C, [alpha]D +9.5 degrees. On acidic hydrolysis, 1 afforded cimigenol (3) as an aglycone, and glucose and arabinose as sugars. On enzymatic hydrolysis with molsin, 1 afforded 24-O-acetylhydroshengmanol 15-O-glucoside (4). On the basis of chemical and spectral data, the structure of 1 was proposed to be (23R,24S)-24-acetoxy-3-O-alpha-L-arabinopyranosyloxy-16,23-e poxy-9,19- 15-O-beta-D-glucopyranoside. The other glycoside (2) showed, in its 13C-NMR spectrum, a pattern of chemical shifts very similar to that of 1. On acidic hydrolysis, 2 afforded cimigenol (3), xylose and glucose. On enzymatic hydrolysis with molsin, 2 afforded 4. From these results, the structure of 2 was proposed to be (23R,24S)-24-acetoxy-3-O-beta-D-xylopyranosyloxy-16,23-epoxy -9,19-cyclolanostane-15 alpha,16 xi,25-triol 15-O-beta-D-glucopyranoside.