Catherine Vieillescazes

Analysis of diterpenic compounds by GC-MS/MS: contribution to the identification of main conifer resins

AbstractThe three principal types of molecules composing diterpenic resins are the abietanes, pimaranes and labdanes. The study of their fragmentation was performed by gas chromatography coupled to an ion trap mass spectrometer, on standards and resins used in paint varnishes: colophony and sandarac. We found that the general fragmentation pattern was mostly governed by the location of the double bonds on the different cycles and the presence of functional groups, and not by the nature of the C13 group in the case of abietanes and pimaranes. As for the labdanes, the loss of their alkyl chain is very specific. This study develops an analytical strategy using tandem mass spectrometry (MS/MS) experiments to validate the proposed mechanisms of fragmentation and to find the ions of interest for the identification of diterpenic molecules. Graphical AbstractAnalysis of diterpenic compounds by GC-MS/MS

LIQUID CHROMATOGRAPHY OF TRITERPENIC RESINS AFTER DERIVATIZATION WITH DANSYL CHLORIDE

A chromatographic method using fluorescing derivatization was developed for the analysis of triterpenoids in natural resins. The separation was performed using a Luna-C18 column, an acetonitrile-water eluant mixture, a flow-rate of 1 mL · min−1. The fluorescent compounds were detected at 530 nm (excitation at 347 nm). A derivatization reaction of hydroxyl groups of triterpenoids using dansyl chloride is described; this process appeared unusual and provided some novelty. The detection limits were obtained in the range of 0.15–0.45 ng/mL (S/N = 3) for dansylated standard compounds. The described procedure allowed the simultaneous determination of twelve triterpenoids present in frankincense species (Boswellia carteri and B. frereana) and was successfully applied to an archaeological sample coming from an Egyptian mummy. Two other resinous materials, dammar and mastic resins employed in Cultural Heritage, were also studied, in which nine and seven triterpenoids are respectively characterized.