title: Detection and identification of quinonemethide triterpenes in Peritassa campestris by mass spectrometry.
abstract: Analysis of tingenone and tingenol quinonemethide triterpenes was made by gas chromatography/mass spectrometry (GC/MS) of their trimethylsilyl (TMS) ethers. An extra TMS group, in addition to those predicted from the known structures, is added to these compounds during the derivatization process. The electron impact mass spectra showed base peaks at m/z 549 and 623, respectively, for the TMS derivatives of tingenone and tingenol, and electrospray (ES) and collision-activated dissociation (CAD) studies indicate that these ions correspond to losses of a methyl group from the derivatives studied. A mechanism, based on ES-MS/MS studies, is suggested for the derivatization and fragmentation pattern.
authors.affiliation: Departamento de Química, UFSCar, Universidade Federal de São Carlos, C.P. 676, C.E.P. 13565-905, São Carlos, SP, Brazil. edson@dq.ufscar.br
authors.forename: Edson
authors.initials: E
authors.lastname: Rodrigues-Filho
authors.forename: Fábio A P
authors.initials: FA
authors.lastname: Barros
authors.forename: João B
authors.initials: JB
authors.lastname: Fernandes
authors.forename: Raimundo
authors.initials: R
authors.lastname: Braz-Filho
mesh_terms: D029753:Celastraceae; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D010936:Plant Extracts / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry; D014315:Triterpenes / Q000032:analysis* / Q000737:chemistry; D053978:Pentacyclic Triterpenes
chemical_list: D010936:Plant Extracts; D014315:Triterpenes; C451004:tingenol; C009492:tingenone; D053978:Pentacyclic Triterpenes