PREPARATIVE ISOLATION AND PURIFICATION OF FLAVONOIDS FROM CUSCUTA CHINENSIS LAM. BY HIGH-SPEED COUNTERCURRENT CHROMATOGRAPHY

Five flavonoids, quercetin-3-O-beta-D-apiofuranosyl-(1 -> 2)-beta-D-galactoside, hyperoside, kaempferol-3-O-beta-D-glucoside, kaempferol, quercetin, and chlorogenic acid, have been isolated and purified for the first time from the seeds of Cuscuta chinensis Lam. By high-speed countercurrent chromatography (HSCCC). Ethyl acetate extract (700mg) was separated by HSCCC using solvent system [ethyl acetate-ethanol-water-acetic acid (4:1:5:0.2, v/v)], yielding 34mg of quercetin-3-O-beta-D-apiofuranosyl-(1 -> 2)-beta-D-galactoside, 27.5mg of chlorogenic acid, 86mg of hyperoside, and 12mg of kaempferol-3-O-beta-D-glucoside. Then we collected tail blowing fluid and evaporated to dryness, obtaining 196mg of extract. Afterwards 196mg of extract used solvent system [chloroform-methanol-water (4:3:2, v/v)] by HSCCC, gaining 53mg of kaempferol and 18mg of quercetin. The purities of six components reach over 95%. The chemical structures of these compounds were identified by electrospray ionization mass spectrometry (ESI-MS), H-1-NMR, and C-13-NMR.