Metabolomic investigation of secondary metabolites of prepared slices of Glycyrrhiza uralensis with different degrees of honey processing / 药学学报

ABSTRACT

A metabolomics method was used to search for chemical markers in prepared slices of Glycyrrhiza uralensis with different degrees of honey processing. Coupled with these metabolomics analytical methods, ultra-performance liquid chromatography with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF/MS) was used to generate global chemical profiles of the raw material of Glycyrrhiza uralensis and the prepared slices. The samples were collected in Shanxi, Hebei Zhangjiakou and Inner Mongolia. A total of 57 chemical components were identified in Glycyrrhiza uralensis by using the UNIFI theoretical database combined with the library of reference samples. Among them, 37 compounds were identified in positive ion mode and 56 compounds were identified in negative ion mode. Unsupervised principal component analysis (PCA) showed that the chemical ingredients differed considerably depending on the extent of processing. Supervised orthogonal partial least squares discriminant analysis (OPLS-DA) was used to differentiate the moderate processing group and the raw group, and partial least squares discriminant analysis (PLS-DA) was used to differentiate the less, the moderate, and the excessive processing groups. The results showed that the contents of glycyrrhizic acid, licoricesaponin G2, and licoricesaponin E2 varied with the extent of processing. The content of these components increased after processing, and reached the highest level when the extent of processing was moderate (P < 0.05). Glycyrrhizic acid, licoricesaponin G2 and licoricesaponin E2 can be regarded as the chemical markers to differentiate the samples with different degrees of processing. These three compounds can be used to monitor the processing of Glycyrrhiza uralensis.