Three new phomalone derivatives from a deep-sea-derived fungus Alternaria sp. MCCC 3A00467

Three new phomalone derivatives, phomalichenones E-G (1-3), and seven known analogues (4-10) were isolated from the cultures of a deep-sea-derived fungus Alternaria sp. MCCC 3A00467. Their structures were elucidated by spectroscopic methods, including the 1D and 2D NMR, and ECD spectrum. Among the compounds isolated, phomalichenone F (2) presented cytotoxic activity against human myeloma cancer U266 cells with IC₅₀ value of 24.99 μg/mL. The most active compound, 10, showed cytotoxicity against U266, HepG2 and A549 cells with IC₅₀ values of 13.26, 14.69 and 24.39 μg/mL, respectively.