Three new eudesmanoids from the Formosan soft coral Nephthea erecta

Chemical investigations on the organic extract of the Formosan soft coral Nephthea erecta led to the isolation of two new eudesmanoids, (4R*,5S*,6Z,10R*)-8-oxo-eudesm-6-en-5α,11-diol (1) and (6E,10R )-4,5-dioxo-11-methoxy-eudesm-6-ene (2), together with one new tri-nor-eudesmane sesquiterpenoid, (4S*,5E,10R*)-7-oxo-tri-nor-eudesm-5-en-4β-ol (3). The structures of metabolites 1–3 were elucidated through extensive spectroscopic analyses and by comparison with those reported in the literature. The anti-inflammatory activity using RAW 264.7 macrophages and their cytotoxicity against selected cancer cells of 1–3 were evaluated in vitro.