title: Advancing HPLC-PDA-HRMS-SPE-NMR Analysis of Coumarins in Coleonema album by Use of Orthogonal Reversed-Phase C18and Pentafluorophenyl Separations.
abstract: A hyphenated procedure involving high-performance liquid chromatography, photodiode array detection, high-resolution mass spectrometry, solid-phase extraction, and nuclear magnetic resonance spectroscopy, i.e., HPLC-PDA-HRMS-SPE-NMR, has proven an effective technique for the identification of compounds in complex matrices. Most HPLC-PDA-HRMS-SPE-NMR investigations reported so far have relied on analytical-scale reversed-phase C18columns for separation. Herein is reported the use of an analytical-scale pentafluorophenyl column as an orthogonal separation method following fractionation of a crude ethyl acetate extract of leaves of Coleonema album on a preparative-scale C18column. This setup allowed the HPLC-PDA-HRMS-SPE-NMR analysis of 23 coumarins, including six new compounds, 8-O-β-d-glucopyranosyloxy-6-(2,3-dihydroxy-3-methylbut-1-yl)-7-methoxycoumarin (4), (Z)-6-(4-β-d-glucopyranosyloxy-3-methylbut-2-en-1-yl)-7-hydroxycoumarin (6), 6-(4-β-d-glucopyranosyloxy-3-methylbut-1-yl)-7-hydroxycoumarin (8), (Z)-7-(4-β-d-glucopyranosyloxy-3-methylbut-2-en-1-yloxy)coumarin (13), (S)-8-(3-chloro-2-hydroxy-3-methylbut-1-yloxy)-7-methoxycoumarin (19), and 7-(3-chloro-2-hydroxy-3-methylbut-1-yloxy)coumarin (20). The use of the pentafluorophenyl column even allowed separation of several regioisomers that are usually difficult to separate using reversed-phase C18columns. The phytochemical investigation described for C. album in this report demonstrates the potential and wide applicability of HPLC-PDA-HRMS-SPE-NMR for accelerated structural identification of natural products in complex mixtures.
authors.affiliation: Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen , Universitetsparken 2, DK-2100 Copenhagen, Denmark.
authors.forename: Rita de Cássia L
authors.initials: RCL
authors.lastname: Lima
authors.affiliation: Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen , Universitetsparken 2, DK-2100 Copenhagen, Denmark.
authors.forename: Simone M
authors.initials: SM
authors.lastname: Gramsbergen
authors.affiliation: Research Center for Plant Growth and Development, School of Biological and Conservation Sciences, University of KwaZulu-Natal Pietermaritzburg , Private Bag X01, Scottsville 3209, South Africa.
authors.forename: Johannes
authors.initials: J
authors.lastname: Van Staden
authors.affiliation: Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen , Universitetsparken 2, DK-2100 Copenhagen, Denmark.
authors.forename: Anna K
authors.initials: AK
authors.lastname: Jäger
authors.affiliation: Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen , Universitetsparken 2, DK-2100 Copenhagen, Denmark.
authors.forename: Kenneth T
authors.identifier: 0000-0003-4487-7886
authors.initials: KT
authors.lastname: Kongstad
authors.affiliation: Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen , Universitetsparken 2, DK-2100 Copenhagen, Denmark.
authors.forename: Dan
authors.initials: D
authors.lastname: Staerk
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003374:Coumarins / Q000032:analysis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010936:Plant Extracts / Q000737:chemistry; D027821:Rutaceae / Q000737:chemistry; D052616:Solid Phase Extraction; D013019:South Africa; D014468:Umbelliferones / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D003374:Coumarins; D010936:Plant Extracts; D014468:Umbelliferones; C007929:herniarin; C031477:7-hydroxycoumarin