Three new sesquiterpene lactones from Inula britannica

One new 1,10-secoeudesmanolide ( 1 ), two eudesmanolides ( 2 and 3 ), together with nine known compounds ( 4 – 12 ) were isolated from the aerial parts of Inula britannica . The structures of the new compounds were elucidated by detailed spectroscopic analysis, including HRESIMS and 2D-NMR spectroscopic method. In addition, compounds 1 – 4 were tested for their inhibitory effects against LPS-induced NO production in RAW264.7 macrophages.