Metabolites with anti-inflammatory activities from the mangrove endophytic fungus Alternaria sp. HN-17

In our ongoing research to discover bioactive compounds from mangrove endophytic fungi, three metabolites have been isolated from Alternaria sp. HN-17, including one new isocoumarin derivative ( 2 ) and one new fatty acid derivative ( 3 ), together with one known analog ( 1 ). Their structures were determined by extensive analysis of Nuclear Magnetic Resonance (NMR) and High-Resolution Electrospray Ionization Mass Spectrometry (HRESIMS) data, and hydrolysis reaction experiments. In vitro, compounds 1 and 2 showed moderate inhibitory effects on lipopolysaccharide (LPS)‑stimulated nitric oxide (N O ) production in RAW 264.7 cells, with IC 50 values of 25.8 and 36.5 µM, respectively. The positive control N ω -methyl- L -arginine ( L -NMMA) showed an IC 50 of 17.7 µM.