Four new chromone derivatives from the Arctic fungus Phoma muscivora CPCC 401424 and their antiviral activities.

The crude extract of the Arctic fungus Phoma muscivora CPCC 401424 displayed anti-influenza A virus activities which led us to investigated their secondary metabolites. Four new chromone derivatives, phomarcticones A-D (1-4) and five known chromone analogs (5-9) have been isolated from Arctic fungus Phoma muscivora CPCC 401424. Compounds 3 and 4 possess rare sulfoxide groups in chromone derivatives. Their structures and absolute configurations were elucidated by extensive analysis of spectroscopic data, electronic circular dichroism, and comparison with reported data. Compounds 3, 7, and 9 showed significant anti-influenza A virus activities with the IC 50 values of 24.4, 4.2, and 2.7 μM, respectively.