Kalshinoids A-F, Anti-inflammatory Sesquiterpenes from Kalimeris shimadae

In a study of the potential anti-inflammatory constituents from Kalimeris shimadae, six new sesquiterpenes, kalshinoids A F (1-6), together with 21 known compounds (7-27), were isolated. The structures and absolute configurations of the new compounds were discerned from extensive spectroscopic analysis, and the absolute configurations of kalshinoids A, B, E, and F were established by ECD calculations. Furthermore, the identified compounds were tested for antiinflammatory activity as assessed by inhibition of tumor necrosis factor-alpha (TNF-alpha) in THP-1 cells. Three sesquiterpenes [kalshinoid F, 4(15)-eudesmen-1 beta,7,11-triol, and 4 alpha,10 alpha,11-trihydroxy-1 beta H,5 beta H-guai-7(8)-ene] reduced levels of TNF-alpha in lipopolysaccharide-stimulated THP-1 cells in a concentration dependent manner and were more potent than dexamethasone. These natural sesquiterpenes merit further investigation as possible anti-inflammatory agents.