title: PREPARATIVE ISOLATION OF ISORHAMNETIN FROM STIGMA MAYDIS USING HIGH-SPEED COUNTERCURRENT CHROMATOGRAPHY.
abstract: Preparative high-speed countercurrent chromatography (HSCCC) has been successfully used for the isolation and purification of isorhamnetin from Stigma maydis. This was achieved in two stages: the first separation was performed with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (HEMW) at a volume ratio of 5:5:5:5, yielding isorhamnetinat 65.6 %, which is followed by the second run using a two-phase solvent system composed of HEMW 5:5:6:4, v/v. From 700 mg of the crude extract 11.8 mg of isorhamnetin was obtained at a high purity of 98%. The final identification was performed by MS, (1)H-NMR and (13)C-NMR spectra.
authors.affiliation: Applied Chemistry Department, Faculty of Sciences, Beijing University of Chemical Technology, 15 Beisanhuan East Road, Chaoyang District, Beijing 100029, China.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Cao
authors.forename: Yun
authors.initials: Y
authors.lastname: Wei
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Ito