title: Determination of naphthodianthrones in plant extracts from Hypericum perforatum L. by liquid chromatography-electrospray mass spectrometry.
abstract: The determination of the naphthodianthrone constituents in extracts of dried blossoms of Hypericum perforatum L. by combined HPLC-electrospray mass spectrometry is described. Hypericin (1), pseudohypericin (2) and their precursor compounds produce intensive negative quasi-molecular ions by deprotonation provided a non-acidic eluent system is used in the HPLC separation. From the [M-H]- ions formed in the electrospray ionization process characteristic daughter ion spectra can be obtained by collisional activation which have been studied by tandem mass spectrometry.
authors.affiliation: Eberhard-Karls-Universität, Institut für Organische Chemie, Tübingen, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Piperopoulos
authors.forename: R
authors.initials: R
authors.lastname: Lotz
authors.forename: A
authors.initials: A
authors.lastname: Wixforth
authors.forename: T
authors.initials: T
authors.lastname: Schmierer
authors.forename: K P
authors.initials: KP
authors.lastname: Zeller
mesh_terms: D000873:Anthracenes; D002851:Chromatography, High Pressure Liquid; D013058:Mass Spectrometry; D010569:Perylene / Q000031:analogs & derivatives* / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*
chemical_list: D000873:Anthracenes; D010936:Plant Extracts; C108324:protopseudohypericin; C108325:protohypericin; D010569:Perylene; C004965:hypericin; C056602:pseudohypericin