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.