Characterization of four Phyllanthus species using liquid chromatography coupled to tandem mass spectrometry.

This paper reports a comparison of four Phyllanthus species (P. amarus, P. stipulatus, P. niruri and P. tenellus), commonly known as stone breaker, by the characterization of the chemical profile of their aqueous extracts. Such characterization was carried out using liquid chromatography coupled to ion trap tandem mass spectrometry (LC-IT-MS(n)) under reversed-phase gradient elution mode. The results of MS/MS and MS(3) on-line experiments, using the electrospray ionization source in the positive and negative mode, are extensively discussed. Furthermore, quercetin-3-O-β-d-glucuronopyranoside was isolated in multimilligram scale from the aqueous extract of P. stipulatus and characterized by mass spectrometry and NMR. Although it is an unusual flavonol in natural products, LC-IT-MS(n) experiments showed it to be present also in P. amarus.