Comparative investigation on metabolites and biological activities of Paeonia ostii stamens from different geographical regions of China

Paeonia ostii is a widely cultivated medicinal and oilseed crop in China. The stamens of P. ostii are important by-products of this crop and conventionally used as tea with putative beneficial effects on human health. However, the in-depth understanding of P. ostii stamens is scarce. In this study, comparative analysis was carried out to systematically characterize the bioactive constituents and biological activities of P. ostii stamens from different geographical regions of China. Seventy-seven secondary metabolites were tentatively identified through untargeted metabolomic analysis based on MS/MS molecular similar networking and other approaches. Targeted metabolomics conjugated with principal component analysis revealed that eight bioactive compounds, including oxypaeoniflorin, pentagalloyl glucose (PGG), paeoniflorin, and albiflorin, were the primary chemical markers for quality control. Habitats substantially affected the content of PGG, and geographical factor of Nujiang (Southern China) significantly promoted the accumulation of PGG. The extracts from peony stamens across all geographical regions exhibited potent antioxidant, antibacterial, antitumor, and anti-neuroinflammation properties, which were strongly correlated with bioactive compounds. Our results provide new insights into P. ostii stamens to be used for pharmaceutical purposes.