title: Identification of phenanthrene derivatives in Aerides rosea (Orchidaceae) using the combined systems HPLC-ESI-HRMS/MS and HPLC-DAD-MS-SPE-UV-NMR.
abstract: BACKGROUND
  In our continued efforts to contribute to the general knowledge on the chemical diversity of orchids, we have decided to focus our investigations on the Aeridinae subtribe. Following our previous phytochemical study of Vanda coerulea, which has led to the identification of phenanthrene derivatives, a closely related species, Aerides rosea Lodd. ex Lindl. & Paxton, was chosen for investigation.
  
  
  OBJECTIVE
  To identify new secondary metabolites, and to avoid isolation of those already known, by means of the combined systems HPLC-DAD(diode-array detector) with high-resolution tandem mass spectrometry (HRMS/MS) and HPLC-DAD-MS-SPE(solid-phase extraction)-UV-NMR.
  
  
  METHODS
  A dereplication strategy was developed using a HPLC-DAD-HRMS/MS targeted method and applied to fractions from A. rosea stem extract. Characterisation of unknown minor compounds was then performed using the combined HPLC-DAD-MS-SPE-UV-NMR system.
  
  
  RESULTS
  The dereplication method allowed the characterisation of four compounds (gigantol, imbricatin, methoxycoelonin and coelonin), previously isolated from Vanda coerulea stem extract. The analyses of two fractions permitted the identification of five additional minor constituents including one phenanthropyran, two phenanthrene and two dihydrophenanthrene derivatives. The full set of NMR data of each compound was obtained from microgram quantities.
  
  
  CONCLUSIONS
  Nine secondary metabolites were characterised in A. rosea stems, utilising HPLC systems combined with high-resolution analytical systems. Two of them are newly described phenanthrene derivatives: aerosanthrene (5-methoxyphenanthrene-2,3,7-triol) and aerosin (3-methoxy-9,10-dihydro-2,5,7-phenanthrenetriol).
authors.affiliation: University of Strasbourg, Faculty of Pharmacy, Laboratory of Pharmacognosy and Bioactive Natural Products, 74, route du Rhin, CS60024, 67400, Illkirch Graffenstaden, France; LVMH recherche, 185 avenue de Verdun, 45800, Saint Jean de Braye, France.
authors.forename: Veronika
authors.initials: V
authors.lastname: Cakova
authors.forename: Aurélie
authors.initials: A
authors.lastname: Urbain
authors.forename: Cyril
authors.initials: C
authors.lastname: Antheaume
authors.forename: Nicole
authors.initials: N
authors.lastname: Rimlinger
authors.forename: Patrick
authors.initials: P
authors.lastname: Wehrung
authors.forename: Frédéric
authors.initials: F
authors.lastname: Bonté
authors.forename: Annelise
authors.initials: A
authors.lastname: Lobstein
mesh_terms: D002851:Chromatography, High Pressure Liquid; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D029595:Orchidaceae / Q000737:chemistry*; D010616:Phenanthrenes / Q000737:chemistry / Q000302:isolation & purification*; D018547:Plant Stems / Q000737:chemistry; D052616:Solid Phase Extraction; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry
chemical_list: D010616:Phenanthrenes; C031181:phenanthrene
keywords: Aerides rosea; HPLC-ESI-HRMS/MS; on-line HPLC-DAD-MS-SPE-UV-NMR; orchids; phenanthrenes