Comparative metabolite profiling of wild and cultivated licorice based on ultra-fast liquid chromatography coupled with triple quadrupole-time of flight tandem mass spectrometry

Abstract

Licorice is one of the ancient and most frequently applied herbs for its diverse phytochemicals. At present, wild resources of licorice have rapidly declined with increasing demand and the proportion of cultivated products in the market is quickly growing. However, the different level in chemical composition between the wild and cultivated licorice may result in the discrepancy in quality and pharmacological activity. Therefore, an ultra-fast liquid chromatography coupled with triple quadrupole-time of flight tandem mass spectrometry (UFLC-Triple TOF-MS/MS) method combined with multivariate statistical analysis technology was employed to explore chemical composition differences. The result showed that total 63 components were identified from licorice samples. The wild and the cultivated licorice are obviously classified into two groups according to principal component analysis (PCA). PCA and partial least squared discrimination analysis (PLS-DA) were also introduced to rapidly find 14 candidate compounds between two ecotypes of licorice. Apart from glycyrrhizin, licorice saponin J2/G2, glyasperin D and dehydroglyasperin D also could be selected as chemical markers based on t-test and variable importance in the projection (VIP) value. Our study successfully established an effective method for exploring metabolite profiling between two ecotypes of licorice and laying the foundation for distinguishing wild and cultivated licorice.