Preparative isolation of imperatorin, oxypeucedanin and isoimperatorin from traditional Chinese herb “bai zhi” Angelica dahurica (Fisch. ex Hoffm) Benth. et Hook using multidimensional high-speed counter-current chromatography

Preparative high-speed counter-current chromatography (CCC) was successfully used for isolation and purification of imperatorin, oxypeucedanin and isoimperatorin from traditional Chinese herb “bai zhi” Angelica dahurica (Fisch. ex Hoffm) Benth. et Hook using multidimensional counter-current chromatography with a pair of two-phase solvent systems composed of n-hexane–ethyl acetate–methanol–water at volume ratios of 1:1:1:1 (v/v) and 5:5:4.5:5.5 (v/v), which had been selected by analytical high-speed counter-current chromatography (HSCCC). Using two preparative units of the CCC centrifuge, which are connected by a column switching valve, about a 300 mg amount of the crude extract was separated, yielding 19.9 mg of imperatorin, 8.6 mg of oxypeucedanin and 10.4 mg of isoimperatorin all at a high purity of over 98%.