Extraction and Separation of Vitisin D, Ampelopsin B and cis-Vitisin A from Iris lactea Pall. var. chinensis (Fisch.) Koidz by Alkaline Extraction-Acid Precipitation and High-Speed Counter-Current Chromatography.

Naturally occurring oligostilbenes are receiving more attention because they exhibit several beneficial effects for health, including hepatoprotective, antitumor, anti-adipogenic, antioxidant, antiaging, anti-inflammatory, anti-microbial, antiviral, immunosuppressive and neuroprotective activities. Thus, they could be of some potentially therapeutic values for several diseases. In this study, we adopted the alkaline extraction-acid precipitation (AEAP) method for extraction of oligostilbenes from the seed kernel of Iris lactea Then, the high-speed counter-current chromatography (HSCCC) was used for preparative isolation and purification of oligostilbenes from the AEAP extracts. Finally, three oligostilbenes, namely vitisin D (73 mg), ampelopsin B (25 mg) and cis-vitisin A (16 mg), were successfully fractionated by HSCCC with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (2:5:3:6, v/v/v/v) from 300 mg of the AEAP extracts in ∼ 190 min. The purities of the three isolated oligostilbenes were all over 95.0% as analyzed by high performance liquid chromatography. They all were isolated from I. lacteal for the first time.The method of AEAP for the preparation of the oligostilbene-enriched crude sample was simple, and the HSCCC technique for the isolation and purification of oligostilbenes was efficient.