title: Analysis of the cyanolichen Lichina pygmaea metabolites using in situ DART-MS: from detection to thermochemistry of mycosporine serinol.
abstract: Direct Analysis in Real Time DART-HRMS is here first applied to the detection of molecules from a lichen, Lichina pygmaea. The aim was to propose an innovative method of in situ detection of lichen secondary metabolites using the possibilities of elemental composition determination available when a DART source is interfaced with a TOF analyzer. Three kinds of samples have been submitted to DART ionization, i.e. an intact thallus, a powder obtained from the crushed lichen and an aqueous extract. In situ analysis of crushed lichen, yields an extensive chemical profile, comparable to what is obtained from the aqueous extract, comprising both major polar metabolites described in literature along with some other signals that could correspond to potentially unknown metabolites. One of the detected secondary metabolites, mycosporine serinol, underwent a dehydration reaction prior to its transfer in the gas-phase by DART ionization. The consideration of the thermal transfers involved in the DART ionization process and the possibility to record time-dependent mass spectra through the use of the TOF analyzer allowed establishing Arrhenius plots of this water molecule loss to obtain associated thermodynamic quantities. The low values of corresponding activation enthalpy (Δr‡Hm° of the order of 25 kJ mol(-1)) enabled formulating some assumption regarding a possible role of such metabolites in the lichen.
authors: Laboratoire de Pharmacognosie, Equipe PNSCM, (ISCR UMR CNRS 6226), Faculté des Sciences Pharmaceutiques et Biologiques, 2 av. du Pr Léon-Bernard, 35042, Rennes Cedex, France.
authors: Pierre
authors: P
authors: Le Pogam
authors: Béatrice
authors: B
authors: Legouin
authors: Anne-Cécile
authors: AC
authors: Le Lamer
authors: Joël
authors: J
authors: Boustie
authors: David
authors: D
authors: Rondeau
mesh_terms: D001203:Ascomycota / Q000737:chemistry / Q000378:metabolism*; D003512:Cyclohexanones / Q000032:analysis* / Q000737:chemistry* / Q000378:metabolism; D008011:Lichens / Q000737:chemistry / Q000378:metabolism*; D013058:Mass Spectrometry / Q000379:methods*; D011409:Propylene Glycols / Q000032:analysis* / Q000737:chemistry* / Q000378:metabolism; D013816:Thermodynamics
chemical_list: D003512:Cyclohexanones; D011409:Propylene Glycols; C544070:mycosporine-serinol
keywords: Arrhenius plots; DART-MS; in situ analysis; lichen metabolites; thermochemistry