Anti-inflammatory sesquiterpene polyol esters from the stem and branch of Tripterygium wilfordii

The stem and branch extract of Tripterygium wilfordii (Celastraceae) afforded seven new dihydroagarofuran sesquiterpene polyesters tripterysines A‒G ( 1 ‒ 7 ) and eight known ones ( 8 ‒ 15 ). The chemical structures of these new compounds were established based on combinational analysis of HR-ESI-MS and NMR techniques. The absolute configurations of tripterysines A‒C ( 1 ‒ 3 ) and E‒G ( 5 ‒ 7 ) were determined by X-ray crystallographic analysis and circular dichroism spectra. All the compounds were screened for their inhibitory effect on inflammation through determining their inhibitory effect on nitric oxide production in LPS-induced RAW 264.7 cells and the secretion of inflammatory cytokines TNF-α and IL-6 in LPS-induced BV2 macrophages. Compound 9 exhibited significant inhibitory activity on NO production with an IC₅₀ value of 8.77 μmol·L⁻¹. Moreover, compound 7 showed the strongest inhibitory effect with the secretion of IL-6 at 27.36%.