Improved identification of phytocannabinoids using a dedicated structure-based workflow

Phytocannabinoids are a broad class of compounds uniquely synthesized by the various strains of Cannabis sativa. Up to date, most investigation on phytocannabinoids have been addressed to the most abundant species, Δ9-tetrahydrocannabinol and cannabidiol, for their well-known wide range of pharmaceutical activities. However, in the recent years a large number of minor constituents have been reported, whose role in cannabis pharmacological effects is of current scientific interest. With the purpose of gaining knowledge on major and minor species and furnishing a strategy for their untargeted analysis, in this study we present an innovative approach for comprehensively identifying phytocannabinoids based on high-resolution mass spectrometry in negative ion mode, which allows discrimination of the various isomeric species. For a faster and more reliable manual validation of the tandem mass spectra of known and still unknown species, an extensive database of phytocannabinoid derivatives was compiled and implemented on Compound Discoverer software for the setup of a dedicated data analysis tool. The method was applied to extracts of the Italian FM-2 medicinal cannabis, resulting in the identification of 121 phytocannabinoids, which is the highest number ever reported in a single analysis. Among those, many known and still unknown unconventional phytocannabinoids have been tentatively identified, another piece in the puzzle of unravelling the many uncharted applications of this matrix.