Anti-inflammatory Steroids from the South China Sea Sponge Spongia officinalis.

One new highly degraded steroid, namely 21-nor-4-ene-chaxine A (1) furnishing a 5/6/5-tricyclic, along with one known related analogue (2), were isolated from the South China Sea sponge Spongia officinalis. Their structures including absolute configurations were established by extensive spectroscopic data analysis, TDDFT-ECD calculation, and comparison with the spectral data previously reported in the literature. Compound 1 represent the new member of incisterols family with a highly degradation in ring B. In vitro bioassays revealed compound 2 exhibited significant anti-microglial inflammatory effect on lipopolysaccharide (LPS)-induced inflammation in BV-2 microglial cells.