Characterization of Quality Marker for Mume Fructus Pulp by Ultra-Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry-Based Untargeted Metabolomics Combined With Biological Activities

Introduction: As a widely used Chinese herbal medicine, Mume Fructus pulp (MFP) has rich nutritional value and biological activity, but its quality control research is relatively scarce.

Objectives: The objective of the study was to evaluate the quality difference between MFPs from different origins and its adulterant apricot pulp (APP), and to identify potential quality markers.

Methods: The chemical compositions were identified by untargeted metabolomics analysis based on ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry combined with feature-based molecular networking. The effect of the test samples on the gene expression of the pro-inflammatory cytokines was investigated by RT-qPCR and ELISA analyses to determine their anti-inflammatory potential. Antioxidant activity was assessed by a free radical scavenging assay. Subsequently, the relationship between biological activity and chemical composition was analyzed by chemometrics, and the quality index of MFP was preliminarily determined. Based on network pharmacology and molecular docking, quality markers of MFP and their possible molecular mechanisms were further determined.

Results: There were significant differences in the contents of flavonoids and organic acids, as well as the anti-inflammatory and antioxidant activities of MFPs from different habitats. Its adulterant APP was not only different from MFP in composition, but also had significantly weaker biological activity. Sixteen compounds were positively correlated with the antioxidant or anti-inflammatory effects of MFP. Combined with network pharmacology and molecular docking, citric acid, maleic acid, rutin, quercetin, isoquercetin, spiraeoside, and hesperidin were identified as potential quality markers of MFP.

Conclusion: This study showed the potential of untargeted metabolomic analysis combined with bioactivity assays in the identification of herbal quality markers.