title: LC-DAD-MS/SPE-NMR hyphenation. A tool for the analysis of pharmaceutically used plant extracts: identification of isobaric iridoid glycoside regioisomers from Harpagophytum procumbens.
abstract: LC-DAD-MS monitored fractionation of a Harpagophytum procumbens DC. (Pedaliaceae) root extract was combined with a hyphenated LC-DAD-MS/SPE-NMR technique, thus providing the spectral data needed for structure elucidation. This approach allowed the characterization of isobaric iridoid glycoside regioisomers present only as minor constituents. The analytes were identified as the (E/Z) pairs of 6'-O-(p-coumaroyl)harpagide (6'-PCHG) and 8-O-(p-coumaroyl)-harpagide (8-PCHG). The fact that 8-(Z)-PCHG constitutes a new natural product underlines the analytical power of this combined approach. Furthermore, derivatives 6'-(Z)- and 6'-(E)-PCHG are new constituents for H. procumbens.
authors.affiliation: Institute of Pharmacy, Department of Pharmacognosy, Leopold Franzens University Innsbruck, Innrain 52, A-6020 Innsbruck, Austria.
authors.forename: Christoph
authors.initials: C
authors.lastname: Seger
authors.forename: Markus
authors.initials: M
authors.lastname: Godejohann
authors.forename: Li-Hong
authors.initials: LH
authors.lastname: Tseng
authors.forename: Manfred
authors.initials: M
authors.lastname: Spraul
authors.forename: Anny
authors.initials: A
authors.lastname: Girtler
authors.forename: Sonja
authors.initials: S
authors.lastname: Sturm
authors.forename: Hermann
authors.initials: H
authors.lastname: Stuppner
mesh_terms: D006027:Glycosides / Q000302:isolation & purification* / Q000494:pharmacology; D031684:Harpagophytum / Q000737:chemistry*; D057889:Iridoid Glycosides; D039823:Iridoids / Q000302:isolation & purification* / Q000494:pharmacology; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry; D011714:Pyrans / Q000737:chemistry
chemical_list: D006027:Glycosides; D057889:Iridoid Glycosides; D039823:Iridoids; D010936:Plant Extracts; D011714:Pyrans; C033250:harpagide