Synthesis and inhibition of NO production activities of 1, 6-O, O-diacylbritannilactone derivatives

Eight 1, 6-O, O-diacetylbritannilactone(OABL)derivatives(compounds 1 - 8 )were synthesized by esterification or reduction of 1-O-diacetylbritannilactone(ABL)isolated from Inula japonica. All derivatives were evaluated for their anti-inflammation activities through the determination of inhibition of nitric oxide(NO)production in lipopolysaccharide(LPS)-induced macrophages. As results, compounds 5 - 8 (IC₅₀< 2 μmol/L)exhibited more potent inhibition of NO production activities than the lead compound OABL.