Identification of the xanthone of the capitulae from Syngonatnhus nitens (Eriocaulaceae) by liquid chromatography tandem mass spectrometry - Pacifico, M. [UNESP]; Hilario, F. [UNESP]; Napolitano, A.; Pizza, C.; Piacente, S.; Vilegas, Wagner [UNESP]; Santos, L. [UNESP] (Georg Thieme Verlag Kg, 2010)