Multivariate analysis of metabolites in Citri Reticulatae Pericarpium and Citri Reticulatae Pericarpium Viride extracts based on metabolomics approach and their antioxidant activity

Citri Reticulatae Pericarpium (CRP) and Citri Reticulatae Pericarpium Viride (CRPV) possess a rich medicinal heritage. While both belonging to the Rutaceae family, they exhibit distinct traditional Chinese medicinal properties, chemical constituents, and pharmacological effects. This study utilizes UPLC-QTOF-MS/MS in conjunction with metabolic amalgamation and multivariate statistical analysis to elucidate the molecular disparities in chemical composition between CRP and CRPV. A comprehensive total of 367 compounds have been delineated, including 147 flavonoids, 110 alkaloids, 25 organic acids, 21 coumarins, 19 glycolides, 17 hydroxyzable tannins, 13 phenols, 11 terpenoids, and 4 anisors. The majority of these constituents are documented here for the first time. The outcomes of non-targeted metabolomics analysis revealed noteworthy disparities in chemical attributes between CRP and CRPV, particularly in flavonoids, phenols, glycosides, and terpenoids. Furthermore, variations in the relative compound content under diverse solvent extractions were elucidated. Notably, the extraction efficiency of the high-polarity solvent methanol surpasses that of the medium-polarity extractant ethyl acetate. The assessment of antioxidant activity revealed that the methanol extract of CRP exhibited an antioxidant capacity akin to that of the ascorbic acid. The extract sample was added to healthy human umbilical vein endothelial cells for cell viability testing, and no cytotoxic effect was observed. This investigation offers a novel vantage point for the thorough analysis and utilization of citrus peel across various stages of maturity.