Development of a Fast and Convenient Method for the Isolation of Triterpene Saponins from Actaea racemosa by High-speed Countercurrent Chromatography Coupled with Evaporative Light Scattering Detection

In the present work, a fast and simple method for the separation and purification of triterpene saponins from Actaea racemosa was successfully established. Accelerated solvent extraction was used for defatting and extracting of the subaerial parts, giving a triterpene enriched crude extract. Size exclusion chromatography was used to separate actein and 23-epi-26-deoxyactein from other triterpenoids, which were collected in a third fraction. This most complex third fraction was applied to high-speed countercurrent chromatography, a well-established technique for the separation of saponins. Separation parameters were first optimized on an analytical level, using a hyphenated HSCCC-ELSD setup, before the system was scaled up to preparative size. The resulting two-phase solvent system, consisting of n-hexane-acetone-ethyl acetate-2-propanol-ethanol-water (3.5 : 1: 2: 1: 0.5 : 2, v/v/v/v/v/v), enabled the isolation of 23-O-acetylshengmanol-3-O-beta-D-xylopyranoside (17.4mg), cimiracemoside D (19.5 mg), 25-O-acetylcimigenol-3-O-beta-D-xylopyranoside (7.1mg) and the aglycone cimigenol (5.9 mg). Purity of the isolated substances was 96.8%, 96.2%, 97.9%, and 98.4%, respectively. The same method was suitable for the purification of actein and 23-epi-26-deoxyactein, with purities of 97.0% and 98.3%.