Specialized metabolite profiling of different Glycyrrhiza glabra organs by untargeted UHPLC-HRMS

Calabrian licorice (roots of G. glabra var. typica), PDO certified, is one of the most valuable commercial within Glycyrrhiza species. Specialized metabolites profiling of below and aboveground parts of PDO Calabrian G. glabra was established by untargeted UHPLC-HRMS either to elucidate their distinctive accumulation among tissues and to gain insight about the chemical composition of leaves and exudate, also to provide fingerprints for PDO products authentication. Roots showed the typical profile of G. glabra, namely glabridin and prenylated phenolic compounds (erybacin B, kanzonol Y, mulberrofuran K isomers, 3-hydroxyglabrol and glabrol) were confirmed as useful species-specific markers for authenticity and traceability of Calabrian licorice. Aerial tissues contained exclusively phenolics compounds, with pinocembrin, prenylated flavanones (licoflavanone and glabranin) and dihydrostilbenes as distinctive metabolites accumulated in the leaf-exudates, and glycosylated flavonoids (isoquercitrin, astragalin and their malonyl derivatives) distributed solely in the inner leaf tissues and flowers. This comparative study provides insights on tissue-distribution of G. glabra specialized metabolites and paves the way for sustainable valorization of untapped resources and improves the economic value of supply licorice-chain.