The combination of DNA barcoding and metabolomics for the multi-constituents characterization of Licorice botanicals

Abstract

Licorice sold as Botanical Dietary Supplements (BDSs) can be obtained from mainly three Glycyrrhiza species: G. glabra, G. uralensis, and G. inflata.1 Therefore, BDSs are composed of either single Glycyrrhiza species, mixtures of Glycyrrhiza species, or even hybrids. A DNA barcoding method2 was optimized and applied for the authentication of 51 licorice acquisitions (capsules, bulk powders, sticks). Complementary chemometric models were developed with samples containing only single authenticated Glycyrrhiza species (37 among 51): PCA/SIMCA were performed on 1H NMR spectra, and CDA was carried out using UHPLC-UV data. These models enabled the chemical distinction of source Glycyrrhiza species, and the metabolomic characterization of licorice mixtures. Together with DNA barcoding, both models were utilized for the identification of Glycyrrhiza hybrids and species outliers. The study demonstrates that the composition in major flavanones and chalcones is specific to each Glycyrrhiza species, and can be used for the characterization of licorice sold as BDSs.3 Additionally, the present work addresses the congruence and complementarity between DNA analysis and metabolomics.