UHPLC-HR-IDX-Orbitrap-MS Profiling of Eryngium triquetrum Vahl: Chemical Characterization and Associated Biological...

High-resolution mass spectrometry is a powerful tool for the comprehensive characterization of complex natural matrices. In this study, ultrahigh-performance liquid chromatography coupled with high-resolution Orbitrap mass spectrometry (UHPLC-HR-IDX-Orbitrap-MS) was employed to profile the chemical composition of the methanolic extract of Eryngium triquetrum Vahl. In addition, total bioactive contents were measured using various colorimetric methods. Cytotoxicity was examined via the Artemia salina lethality bioassay, and anti-denaturation activity was tested by the protein thermal-induced denaturation test. The membrane-destabilizing effect was assessed using an erythrocyte model, and the antioxidant ability was evaluated by five different methods. UHPLC-HR-IDX-Orbitrap-MS analysis revealed a variety of biomolecules comprising 66 putative compounds across multiple classes of natural compounds, namely, flavonoids, fatty acids, triterpenoids, alkaloids, sesquiterpenoids, diterpenoids, glycoside derivatives, and heterocyclic compounds. Fatty acids and flavonoids were the predominant constituents found in the methanolic extract (ETME). Despite relatively low total phenolic and moderate terpenoid contents, the extract exhibited strong total antioxidant capacity and significant hydroxyl radical-scavenging activity (IC₅₀ = 49.21 μg/mL), with moderate metal-reducing and chelation effects. The methanolic extract caused low erythrocyte membrane lysis (30% at 2.5 mg/mL), whereas significant cytotoxicity was observed (LD₅₀ = 9.25 μg/mL). In addition, a strong anti-denaturation effect (IC₅₀ = 157.8 μg/mL) was recorded. Overall, the present study highlights the effectiveness of UHPLC-HR-IDX-Orbitrap-MS for detailed chemical characterization of E. triquetrum and provides analytical insight into the relationship between high-resolution mass spectrometric profiling and associated biological activities of complex plant extracts.