Anti-inflammatory norditerpenoids from the soft coral Sinularia maxima

Two new norditerpenoids, 12-hydroxy-scabrolide A (2), 13-epi-scabrolide C (6) and five know compounds (1, 3–5, 7) were isolated from the methanol extract of the soft coral Sinularia maxima. They were evaluated for inhibitory effects on lipopolysaccharide-stimulated production of pro-inflammatory cytokines in bone marrow-derived dendritic cells (BMDCs). Compound 6 potently inhibited IL-12 and IL-6 production in LPS-stimulated bone marrow derived dendritic with IC50 values ranging from 5.30±0.21 to 13.12±0.64μM. Compound 1 exhibited moderate inhibitory activity against IL-12 and IL-6 production with IC50 values ranging from 23.52±1.37 to 69.85±4.11μM. Chemical investigation of the soft coral Sinularia maxima resulted in the isolation of seven norditerpenoids, including two new compounds, 12-hydroxy-scabrolide A (2) and 13-epi-scabrolide C (6). The structures of the isolated compounds were elucidated based on extensive spectroscopic evidence including Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) and both one- and two-dimensional nuclear magnetic resonance (1D and 2D NMR, respectively), in comparison with reported data. Compound 6 potently inhibited IL-12 and IL-6 production in LPS-stimulated bone marrow derived dendritic (BMDCs) with IC50 values of 5.30±0.21 and 13.12±0.64μM, respectively. Compound 1 exhibited moderate inhibitory activity against IL-12 and IL-6 production with IC50 values of 23.52±1.37 and 69.85±4.11μM, respectively.