Dysideanones F-G and dysiherbols D-E, unusual sesquiterpene quinones with rearranged skeletons from the marine sponge Dysidea avara

Four new sesquiterpene quinone meroterpenoids, dysideanones F-G (1-2) and dysiherbols D-E (3-4), were isolated from the marine sponge Dysidea avara collected from the South China Sea. The new structures were elucidated by extensive analysis of spectroscopic data including HR-MS and 1D and 2D NMR spectra, and their absolute configurations were assigned by single-crystal X-ray diffraction and ECD calculations. Anti-inflammatory evaluation showed that dysiherbols D-E (3-4) exhibited moderate inhibitory activity on TNF-alpha-induced NF-kappa B activation in human HEK-293T cells with IC50 values of 10.2 and 8.6 mu mol.L-1, respectively.