title: Identification of the major constituents of Hypericum perforatum by LC/SPE/NMR and/or LC/MS.
abstract: The newly established hyphenated instrumentation of LC/DAD/SPE/NMR and LC/UV/(ESI)MS techniques have been applied for separation and structure verification of the major known constituents present in Greek Hypericum perforatum extracts. The chromatographic separation was performed on a C18 column. Acetonitrile-water was used as a mobile phase. For the on-line NMR detection, the analytes eluted from column were trapped one by one onto separate SPE cartridges, and hereafter transported into the NMR flow-cell. LC/DAD/SPE/NMR and LC/UV/MS allowed the characterization of constituents of Greek H. perforatum, mainly naphtodianthrones (hypericin, pseudohypericin, protohypericin, protopseudohypericin), phloroglucinols (hyperforin, adhyperforin), flavonoids (quercetin, quercitrin, isoquercitrin, hyperoside, astilbin, miquelianin, I3,II8-biapigenin) and phenolic acids (chlorogenic acid, 3-O-coumaroylquinic acid). Two phloroglucinols (hyperfirin and adhyperfirin) were detected for the first time, which have been previously reported to be precursors in the biosynthesis of hyperforin and adhyperforin.
authors.affiliation: Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, University Campus, Ioannina, Epirus GR-45110, Greece.
authors.forename: Evangelos C
authors.initials: EC
authors.lastname: Tatsis
authors.forename: Sjef
authors.initials: S
authors.lastname: Boeren
authors.forename: Vassiliki
authors.initials: V
authors.lastname: Exarchou
authors.forename: Anastassios N
authors.initials: AN
authors.lastname: Troganis
authors.forename: Jacques
authors.initials: J
authors.lastname: Vervoort
authors.forename: Ioannis P
authors.initials: IP
authors.lastname: Gerothanassis
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D005419:Flavonoids / Q000737:chemistry* / Q000302:isolation & purification; D020902:Hypericum / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D013058:Mass Spectrometry / Q000379:methods*
chemical_list: D005419:Flavonoids