Untargeted Metabolomics Based on UPLC-Q-Exactive-Orbitrap-MS/MS Revealed the Differences and Correlations between Different Parts of the Root of Paeonia lactiflora Pall.

BACKGROUND: Paeonia lactiflora Pall. (PLP) is a plant with excellent ornamental and therapeutic value that can be utilized in traditional Chinese medicine as Paeoniae Radix Alba (PRA) and Paeoniae Radix Rubra (PRR). PRA must undergo the "peeling" process, which involves removing the cork and a portion of the phloem. PLP's biological function is strongly linked to its secondary metabolites, and the distribution of metabolites in different regions of the PLP rhizome causes changes in efficacy when PLP is processed into various therapeutic compounds. METHODS: The metabolites of the cork (cor), phloem (phl), and xylem (xyl) were examined in the roots of PLP using a metabolomics approach based on UPLC-Q-Exactive-Orbitrap-MS/MS (UPLC-MS/MS), and the differential metabolites were evaluated using multivariate analysis. RESULTS: Significant changes were observed among the cor, phl, and xyl samples. In both positive and negative ion modes, a total of 15,429 peaks were detected and 7366 metabolites were identified. A total of 525 cor-phl differential metabolites, 452 cor-xyl differential metabolites, and 328 phl-xyl differential metabolites were evaluated. Flavonoids, monoterpene glycosides, fatty acids, sugar derivatives, and carbohydrates were among the top 50 dissimilar chemicals. The key divergent metabolic pathways include linoleic acid metabolism, galactose metabolism, ABC transporters, arginine biosynthesis, and flavonoid biosynthesis. CONCLUSION: The cor, phl, and xyl of PLP roots exhibit significantly different metabolite types and metabolic pathways; therefore, "peeling" may impact the pharmaceutical effect of PLP. This study represents the first metabolomics analysis of the PLP rhizome, laying the groundwork for the isolation and identification of PLP pharmacological activity, as well as the quality evaluation and efficacy exploration of PLP.

Determination of monosaccharides in Lycium barbarum fruit polysaccharide by an efficient UHPLC-QTRAP-MS/MS method.

INTRODUCTION: Pre-column derivatisation using 1-phenyl-3-methyl-5-pyrazolone (PMP) is a common method for monosaccharide determination. Herein, a specific ultra-high-performance liquid chromatography quadrupole trap tandem mass spectrometry (UHPLC-QTRAP-MS/MS) method was developed and used for the determination of monosaccharide composition of Lycium barbarum polysaccharide (LBP). OBJECTIVE: Exploration of a new efficient method for monosaccharide determination. METHODS: In our study, hydrochloric acid was used to hydrolyse the polysaccharide obtained from L. barbarum fruits. Principal component analysis (PCA) and technique for order of preference by similarity to ideal solution (TOPSIS) analysis were used for comprehensive evaluation of the samples. The results showed that LBP was composed of seven monosaccharides: galactose, arabinose, mannose, rhamnose, xylose, ribose, and glucose. The linear relationship of the seven monosaccharides was optimum within a certain concentration range. Quantitative recoveries of the seven monosaccharides from the samples ranged from 94.76% to 102.11%. RESULTS: A rapid quantitative detection method was established, in which the hydrolysis time was reduced from 12 h to 2 h. By using LBP as one of the indexes to evaluate the quality of L. barbarum, L. barbarum from Zhongning County, Ningxia Province, was identified as having the best quality among the varieties tested. CONCLUSION: The UHPLC-QTRAP-MS/MS pre-column derivatisation method used in this study was simple, accurate, and sensitive, with good repeatability, and can be used for quality evaluation and origin distinction of L. barbarum and other medicinal plants.