Identification of Nutritional Ingredients and Medicinal Components of Pueraria lobata and Its Varieties Using UPLC-MS/MS-Based Metabolomics

Pueraria lobata and its variety P. lobata var. thomsonii are both traditional Chinese medicines that have high nutritional and medical value; whereas another variety, P. lobata var. montana has low nutritional and medicinal value and can cause ecological disasters. The material basis of different nutritional and medicinal values, which are caused by metabolite differences among these varieties, remains to be further clarified. Here, we performed ultra performance liquid chromatography-tandem mass spectrometry based widely targeted metabolome analysis on Pueraria lobata, P. lobata var. thomsonii, and P. lobata var. montana. Among them, a total of 614 metabolites were identified, and distinguished from each other using orthogonal partial least squares discriminant analysis. Our results suggest that the nutritional differences between P. lobata and its varieties can be explained by variations in the abundance of amino acids, nucleotides, saccharides, and lipids; differences in flavonoids, isoflavones, phenolic acids, organic acids, and coumarins contents caused the differences in the medicinal quality of P. lobata and its varieties. Additionally, the key metabolites responsible for the classification of the three Pueraria varieties were identified. This study provides new insights into the underlying metabolic causes of nutritional and medicinal variation in P. lobata and its varieties.