Unraveling the anti-inflammatory effects of Thliphthisa antalyensis: Isolation, structural characterization, and in...

Activity-guided fractionation on the EtOH extract prepared from the whole plant of Thliphthisa antalyensis (Ehrend.) P.Caputo & Del Guacchio led to the isolation and characterization of 11 secondary metabolites (1-11). Besides, nine more compounds (12-20), including a previously unreported megastigmane glycoside (12) were obtained from the less-active fractions. Their chemical structures were elucidated using 1D and 2D NMR and HRMS. The crude EtOH extract, solvent fractions, main fractions, and isolates (1-12) were evaluated for their in vitro anti-inflammatory activities in LPS-stimulated RAW 264.7 murine macrophage cells. Compounds 1, 6, 7, and 10 displayed mild to moderate nitric oxide (NO) inhibitory activity (IC₅₀ 104.53-168.49 μM). Their effects on TNF-α, IL-6, PGE₂ release, and COX-2 expression were further assessed. The chemotaxonomic significance of the isolated compounds was also discussed. This is the first study of the phytochemical and anti-inflammatory activities of T. antalyensis, an endemic species to Türkiye.