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-α-induced NF-κB activation in human HEK-293T cells with IC50 values of 10.2 and 8.6 μmol·L—1, respectively.