Cytotoxic Xanthone Derivatives from the Mangrove-Derived Endophytic Fungus Peniophora incarnata Z4

The mangrove-derived endophytic fungus Peniophora incarnata Z4 produced seven new xanthone derivatives, including four new tetrahydroxanthones ( 1 – 4 ), one new chromone ( 5 ), one new xanthone ( 6 ), and one new xanthone dimer ( 7 ), together with one known compound, globosuxanthone B ( 8 ). Their structures were determined by an extensive analysis of 1D and 2D NMR, HRESIMS, ECD, and single-crystal X-ray diffraction data. In cytotoxic activity assays, compound 2 showed cytotoxicity against three carcinoma cell lines with IC 50 values less than 10 μM.