Rapid Screening of Secondary Plant Metabolites using Two-Dimensional Tandem Mass Spectrometry

Abstract

The full 2D tandem mass spectrometry (MS/MS) data domain provides a rapid survey of the chemical components of complex plant extracts without subjecting them to prior chromatographic separation. Nano electrospray ionization (nESI), desorption electrospray ionization (DESI) and paper spray ionization are used to create an ion mixture representative of the chemical constituents of a plant extract, then mass-selective collision-induced dissociation (CID) is used to automatically record fragments from each precursor ion in the mixture. Signal extraction from the 2D data domain yields matching spectra to conventional product and precursor ion scans and displays distributions of compounds bearing a chosen functionality. These features and other manipulations of the 2D MS/MS data are demonstrated using crude extracts of Artemisia annua (Sweet wormwood). Similarities and differences in the secondary metabolites of plant species are established rapidly by inspection of the 2D MS/MS plots. The methodology is characterized by the high speed of data acquisition while the limited mass resolution still allows high speed snapshots of chemistry.