Two phenylethanoid glycosides(PhGs), plantamajoside and acteoside, were isolated and purified from the aerial parts of Plantago asiatica for the first time by high performance centrifugal partition chromatography(HPCPC) with ethyl acetate, n-butanol, ethanol and water(0.5:0.5:0.1:1, volume ratio) as solvent system. A total of 45.6 mg of plantamajoside and 293.8 mg of acteoside were purified from 1341 mg of the n-butanol extract of P. asiatica, with a purity of >93.3% as determined by HPLC. The HPCPC fractions were analyzed by HPLC-DAD and the structures were identified by their retention time, UV, electrospray ionization multi stage tandem mass spectrometry(ESI-MSn) in the negative ion mode, and confirmed by NMR experiments. The characteristic fragment ions of ESI-MS of the two PhGs isolated from Plantago asiatica were discussed, which are specific and useful for the identification of the structures of PhGs.
LI LiLIU Chun-mingCHEN Zhao-jieWANG JingSHI Dong-fangLIU Zhi-qiang
