Non-targeted metabolomics-based molecular networking enables the chemical characterization of Rumex sanguineus

Rumex sanguineus, a traditional medicinal plant of the Polygonaceae family, is gaining popularity as an edible resource. However, despite its historical and nutritional significance, its chemical composition remains poorly understood. To deepen the understanding of the chemical composition of Rumex sanguineus, an in-depth analysis using non-targeted, mass spectrometry-based metabolomics was performed. Rumex roots, stems and leaves samples were extracted and analyzed by UHPLC-HRMS and subsequently subjected to feature-based molecular networking. Overall, 347 primary and specialized metabolites were annotated by spectral matching with established libraries in positive and negative ionization modes that could be grouped into 8 biochemical classes. Most of the annotated metabolites (60 %) belong to the polyphenols and anthraquinones classes. To investigate potential’ toxicity due to the presence of anthraquinones, the amount of emodin was quantified with analytical standard, revealing higher accumulation in leaves compared to stems and roots. This highlights the need for thorough metabolomic studies to understand both beneficial and harmful compounds, especially in plants with historical medicinal use transitioning to modern culinary use.