title: Combination of integrated expanded bed adsorption chromatography and countercurrent chromatography for the direct extraction and purification of pseudohypericin and hypericin from St. John's wort (Hypericum perforatum L.).
abstract: St. John's wort has attracted particular attention because of its beneficial effects as an antidepressant, antiviral, and anticancer agent. A method for the combination of integrated expanded bed adsorption chromatography and countercurrent chromatography for the simultaneous extraction and purification of pseudohypericin and hypericin from the herb is presented in this paper. Firstly, the constituents were extracted and directly adsorbed by expanded bed adsorption chromatography under optimal conditions. The stepwise elution was then performed by expanded bed adsorption chromatography that enriched the targets with higher purities and recoveries compared to other methods. Secondly, the eluent fractions from expanded bed adsorption chromatography were further separated by two-step high-speed countercurrent chromatography. A two-step high-speed countercurrent chromatography method with a biphasic solvent system composed of n-hexane/ethyl acetate/methanol/water with a volume ratio of 1:2:1:2 was performed by stepwise changing the flow rate of the mobile phase. Consequently, 5.6 mg of pseudohypericin and 2.2 mg of hypericin with purities of 95.5 and 95.0%, respectively, were successfully obtained from 40 mg of crude sample.
authors.affiliation: Laboratory of Functional Materials Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China.
authors.forename: Fanfan
authors.initials: F
authors.lastname: Cai
authors.affiliation: Laboratory of Functional Materials Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.affiliation: Shanghai Key Laboratory of New Drug Design & Modern Engineering Center for TCM, School of Pharmacy, East China University of Science and Technology, Shanghai, China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Laboratory of Functional Materials Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China.
authors.forename: Hongyang
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Laboratory of Functional Materials Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China.
authors.forename: Yuerong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Laboratory of Functional Materials Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, China.|State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Macau, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Hu
keywords: Countercurrent chromatography; Expanded bed adsorption chromatography; Hypericin; Pseudohypericin; St. John's wort