UHPLC-DAD-QToF-MS profiling and marker compound analysis of Tetragonia tetragonoides: phytochemical characterization and assessment of anti-inflammatory activity.

Tetragonia tetragonoides (Pall.) Kuntze is a perennial coastal species traditionally used for gastrointestinal ailments, mainly for its anti-inflammatory activity; however, its secondary metabolite profile has not been systematically characterized for analytical purposes. In this study, two major acylated methoxykaempferol glycosides were isolated by preparative liquid chromatography and their structures elucidated by NMR spectroscopy as tetragonoside derivatives. A validated analytical workflow was established for chemical profiling and quantitative determination of leaf samples collected from five coastal regions of Jeju Island, South Korea, using UHPLC-DAD-QToF-MS. Across accessions, the contents of both marker compounds, compound 1 and tetragonoside A (2), ranged from 1.3-3.3 mg g-1 and 1.0-1.7 mg g-1, respectively. Using both MS ionization modes, together with diagnostic fragment ions and neutral losses generated by collision-induced dissociation, 71 compounds were putatively identified in T. tetragonoides leaf samples. The extract was further evaluated in human periodontal ligament cells, where significant suppression of LPS-induced pro-inflammatory gene expression was observed. This study provides a comparative phytochemical characterization and marker compound analysis of T. tetragonoides, thereby providing a foundation for quality control and supporting a chemically informed interpretation of its biological activity.