Anti-inflammatory germacrane-type sesquiterpene lactones from Vernonia sylvatica

Nine new germacranolides, sylvaticalides A-H (1-9), 1 - 9 ), and three known analogues ( 10-12 ) were isolated from the aerial part of Vernonia sylvatica. . Their structures were established using comprehensive spectroscopic analysis, including high-resolution electrospray ionization mass spectroscopy (HR-ESI-MS) and 1D and 2D nuclear magnetic resonance (NMR) spectra. Their absolute configurations were determined by X-ray diffraction experiments. The anti-inflammatory activities of all isolated compounds were assessed by evaluating their inhibitory effects on the nuclear factor kappa B (NF-kappa B) pathway, which was activated by lipopolysaccharide (LPS)-stimulated human THP1-Dual cells, and the interferon-stimulated gene (ISG) pathway, activated by STING agonist MSA-2 in the same cell model. Compounds 1 , 2 and 6 showed inhibitory effects on the NF-kappa B and ISG signaling pathways, with IC50 50 values ranging from 4.12 to 10.57 mu mol<middle dot>L-1. -1 .