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

Abstract

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°C, [α]_D +21.0° and 3-xylosyl-24-O-acetylhydroshengmanol 15-glucoside (2), C₄₃H₇₀O₁₆, mp 208-210°C, [α]_D+9.5°. 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-α-L-arabinopyranosyloxy-16, 23-epoxy-9, 19-cyclolanostane-15α, 16ξ, 25-triol 15-O-β-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-β-D-xylo-pyranosyloxy-16, 23-epoxy-9, 19-cyclolanostane-15α, 16ξ, 25-triol 15-O-β-D-glucopyranoside.