Bioactivity-guided isolation of a methanolic extract of Euphorbia fischeriana led to the isolation of four new abietane-type diterpenoids, fischeriolides A-D (1-4), together with 11 known diterpenoids. Their structures were elucidated based on the interpretation of 1D and 2D NMR spectroscopic and HRESIMS data. The absolute configuration of compound 3 was determined by single-crystal X-ray diffraction analysis and electronic circular dichroism methods. Compounds 5-9 exhibited inhibitory effects on LPS-induced nitric oxide production in RAW 264.7 macrophages with IC50 values in the range 4.9-12.6 μM.

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Three new neo-clerodane diterpenoids (1-3) along with 12 known compounds (4-15) were isolated from a methanol extract of the aerial parts of Scutellaria barbata. The structures of 1-3 were determined by interpretation of their 1D and 2D NMR spectroscopic data as well as HRESIMS values. All isolated compounds were tested for their inhibitory effects on LPS-induced nitric oxide production in RAW 264.7 macrophages. Compounds 1-4, 7, and 10-12 were found to inhibit nitric oxide production with IC50 values ranging from 20.2 to 35.6 μM.

A new oplopane-type sesquiterpenoid tussilagofarin (1) and a new chromone tussilagofarol (2), along with 18 known compounds 3-20, were isolated from the flower buds of Tussilago farfara. The structures of the new compounds were elucidated on the basis of 1D and 2D NMR and HRESIMS data. Of the isolated compounds, oplopane- and bisabolane-type sesquterpenoids 1, 8-12, 15, and 16 were found to inhibit nitric oxide production in LPS-induced RAW 264.7 cells with IC50 values of 3.5-28.5 μM.

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