Anti-inflammatory sesquiterpene dimers and diterpenes from the aerial part of Inula japonica

Phytochemical investigation on the 95% alcohol extract of the aerial part of Inula japonica led to the isolation of three new compounds, inulanolides F-G (1-2) and 17 alpha-carboxaldehyde-ent-kaur-18-oic acid (3), together with four known compounds (4-7). The structures of new compounds were elucidated by using spectroscopic data. Most of the isolated compounds showed significant anti-inflammatory activities.