Isolation of imperatorin, oxypeucedanin, and isoimperatorin from Angelica dahurica (Fisch ex Hoffm) Benth. et Hook by stepwise flow rate high-speed countercurrent chromatography

Stepwise flow rate preparative high-speed countercurrent chromatography (HSCCC) was successfully used for isolation and purification of imperatorin, oxypeucedanin, and isoimperatorin from a crude root extract of Angelica dahurica (Fisch. ex Hoffm) Benth. et Hook. The separation was performed with a two-phase solvent system composed of n-hexane-ethylacetate-methanol-water at volume ratio of 5: 5: 4: 6, v/v/v/v, which had been selected by analytical HSCCC. About a 600 mg amount of the crude extract was separated in a one step operation, yielding 35.6 mg of imperatorin, 16.4 mg of oxypeucedanin, and 22.7 mg of isoimperatorin, all at a high purity of over 98%.