SEPARATION OF THREE BIOACTIVE ISOMERS FROM BIDENS PILOSA BY COUNTERCURRENT CHROMATOGRAPHY.

Under LC-TOF-MS fraction-guided analysis, then-butanol was extracted fromBidens pilosa. Three bioactivity isomers compounds, including methyl 3,4-dicaffeoyl quinate (1), methyl 3,5-dicaffeoyl quinate (2), and methyl 4,5-dicaffeoyl quinate (3) were successfully isolated by countercurrent chromatography (CCC) with two phase solvent system composed of chloroform-methanol-water-n-buthanol (4:3:2:0.5, v/v) elution. Their purities were 93.7%, 82.4%, and 91.8% determined by HPLC. HR-ESI-MS and NMR was used to confirm their structures. This is the first time the isolation of geometrical isomers of methyl dicaffeoyl quinates by CCC has been reported. [ABSTRACT FROM AUTHOR]