Two γ-Lactone Derivatives With Anti-Inflammatory Activities From a Mangrove Endophytic Fungus Alternaria sp. HN-17.

Two γ-lactone derivatives, alterlactones A-B (1-2), along with one known analogue 3, were isolated from the mangrove endophytic fungus Alternaria sp. HN-17. Their structures were elucidated using comprehensive spectroscopic methods, including 1D and 2D NMR, HRESIMS, and electronic circular dichroism (ECD) calculations. Compounds 1 and 2 showed significant anti-inflammatory activity with IC50 values of 10.2 and 13.5 µM, respectively.