Caracterização de quatro espécies de quebra-pedra utilizando cromatografia líquida de alta eficiência hifenada a espectrometria de massa em múltiplos estágios

Abstract

This work presents the results of the use of High Performance Liquid Chromatography coupled to mass spectrometry in the chemical differentiation/characterization of aqueous extracts of plant samples of the genus Phyllanthus, commonly named as "stone braker". The species studied were P. amarus, P. stipulatus, P. niruri and P. tenellus. For medical purposes, the Brazilian Pharmacopoeia recognizes only P. niruri and P. tenellus. Samples of the plants used were grown and collected on the campus of Federal University of São Carlos (UFSCar). The goal of the work here reported was to compare the four species through the characterization of secondary metabolites. Structural characterization of secondary metabolites was achieved by interpretation of fragmentation data obtained in the online experiments of MS/MS and MS3using ion trap mass spectrometer equipped with an electrospray ionization source in positive and negative mode of ionization. Several chemical compounds were elucidated; some of them presents in all four species while others were found in a single species, this work presents and discusses the results. Furthermore two compounds from the species of P. stipulatus were isolated by semi-preparative liquid chromatography. These two isolated compounds were fully characterized by mass spectrometry and NMR, as corilagin and quercetin-3-O-β-D-glucuronopyranoside, an unusual flavonol in natural products