Anti-inflammatory Polyketides from the Marine-Derived Fungus Eutypella scoparia

Three new polyketides, eutyketides A and B (1 and 2) and cytosporin X (3), along with four known compounds (4–7), were obtained from the marine-derived fungus Eutypella scoparia. The planar structures of 1 and 2 were elucidated by extensive HRMS and 1D and 2D NMR analyses. Their relative configurations of C-13 and C-14 were determined with chemical conversions by introducing an acetonylidene group. The absolute configurations of 1–3 were determined by comparing their experimental electronic circular dichroism (ECD) data with their computed ECD results. All of the isolated compounds were tested for their anti-inflammatory activities on lipopolysaccharide-induced nitric oxide production in RAW 264.7 macrophages. Compounds 5 and 6 showed stronger anti-inflammatory activities than the other compounds, with the inhibition of 49.0% and 54.9% at a concentration of 50.0 µg/mL, respectively.