title: Characterization of polyprenylated xanthones in Garcinia xipshuanbannaensis using liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry.
abstract: A reliable and sensitive on-line high-performance liquid chromatography (HPLC) coupled with electrospray quadrupole time-of-flight tandem mass spectrometry (ESI-QTOF-MS/MS/MS) method has been optimized and established for the analysis of polyprenylated xanthones in the plant Garcinia xipshuanbannaensis. Collision induced MS/MS techniques were used to fragment the precursor molecular ions and MS/MS/MS techniques based on cone voltage fragmentation were used to further break down the resulting product ions sequentially. It was found that Retro-Diels-Alder rearrangement occurred from the xanthone skeleton in the MS/MS/MS process and produced characteristic fragment ions, which are useful for differentiating some positional isomers containing the prenyl unit on the A ring or B ring. Complementary fragmentation information, for instance the successive loss of prenyl residues, is also valuable for the identification of this class of xanthones. Under optimized HPLC-MS/MS/MS method, a total of 15 prenylated xanthones could be separated within 10 min. This method also provided information about the molecular formula of a precursor molecule and its fragments, which could be used for dereplication of known or likely new prenylated xanthones in Garcinia plants before the purification and structural elucidation process.
authors.affiliation: Hong Kong Jockey Club Institute of Chinese Medicine, Shatin, New Territories, Hong Kong, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhou
authors.forename: Quan-Bin
authors.initials: QB
authors.lastname: Han
authors.forename: Jing-Zheng
authors.initials: JZ
authors.lastname: Song
authors.forename: Chun-Feng
authors.initials: CF
authors.lastname: Qiao
authors.forename: Hong-Xi
authors.initials: HX
authors.lastname: Xu
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D029760:Garcinia / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D044004:Xanthones / Q000737:chemistry*
chemical_list: D044004:Xanthones