Bioactive sesquiterpene quinols and quinones from the marine sponge Dysidea avara

Four new sesquiterpene quinols, dysiquinols A-D (1-4), and four new sesquiterpene quinones, (5S, 8S, 9R, 10S)-18-ethoxyneoavarone (5), (5S, 8S, 9R, 10S)-19-ethoxyneoavarone (6), (5R, 8R, 9S, 10R)-18-ethoxyavarone (7), and (5R, 8R, 9S, 10R)-19-ethoxyavarone (8), together with a known compound, avarol (9), were isolated from the South China Sea marine sponge Dysidea avara. The planar structures of new compounds were elucidated by interpretation of HRESIMS and 2D NMR spectroscopic data, and their absolute configurations were determined by comparison between the calculated and experimental ECD spectra. The cytotoxicity of 1-9 against human myeloma cancer cell line NCI-H929 and their NF-kappa B inhibitory activity were evaluated. Among these metabolites, dysiquinol D (4) showed the most potent cytotoxic and NF-kB inhibitory activities with IC50 values of 2.8 and 0.81 mu M, respectively.