Comprehensive metabolic profile analysis of the root bark of different species of tree peonies (Paeonia Sect. Moutan)

Tree peonies (Paeonia Sect. Moutan) are well-known for their medicinal and ornamental uses but most wild species in the Moutan section are endangered. The comprehensive metabolomics evaluation of tree peonies is essential to distinguish different species and to identify undescribed compounds, thereby elucidating the diversity of their metabolites and discovering potential active ingredients. In this study, the metabolome variations of root barks of nine species and their varieties collected from one botanical garden after years of localization were systematically investigated. A digital database of specialized metabolites was established to improve feature identification or annotation and various bio- and cheminformatics tools were employed to analyse and visualize the profiled metabolomic data. As a result, 384 compounds were identified or annotated, including various monoterpene glycosides, flavonoids, phenols, terpenoids and steroids, tannins, stilbenes and others. All samples were clearly divided into two subsections: Vaginatae and Delavayanae. The distribution and abundance of metabolites were also analysed and discussed in order to find potential biomarkers in different wild tree peonies.