Application of SALDI Mass Spectrometry to the Rapid Screening of Diarylheptanoids in Plant Extracts

Diarylheptanoids (DAH) are a class of phenolic secondary plant metabolites possessing a wide range of biological activities and pronounced antioxidant properties. This study proposes an original approach to the rapid screening of diarylheptanoids in plant extracts, based on surface-assisted laser desorption/ionization (SALDI) mass spectrometry on target plates with carbon nanocoating and cationization with lithium ions. The test sample was an extract of birch phloem containing centrolobol (CL) and platyphyllonol (PF), the structures of which were confirmed by NMR spectroscopy. The high intensity of diarylheptanoid signals in the resulting mass spectra made it possible to use tandem mass spectrometry for their search and identification. Using the developed approach, four glycosylated derivatives of CL and PF were discovered and tentatively identified in the studied extract, including those containing monosaccharide and disaccharide residues with pentose and hexose sugars.