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‐ethyl acetate‐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%.