New aromatic polyketides from the marine-derived fungus Pseudopithomyces maydicus PSU-AMF350 and their antimicrobial activity.

Four new aromatic polyketides including two diphenyl ethers (pseudopithoethers A-B, 1 - 2 ), one benzofuranone (pseudopithonone, 3 ) and one xanthone (pseudopithoxanthone, 4 ), along with two known compounds ( 5 - 6 ) and one new naturally occurring hydroquinone (α,2,5-trihydroxyacetophenone, 7 ) were isolated from the marine-derived fungus Pseudopithomyces maydicus PSU-AMF350. Their structures were identified by analysis of spectroscopic data. All isolated compounds were tested for antimicrobial activity. Only compound 7 displayed antibacterial activity against methicillin-resistant Staphylococcus aureus with the MIC value of 128  µ g/mL and against S. aureus , Acinetobacter baumannii NPRC005 and A. baumannii NPRC007 with the same MIC value of 200  µ g/mL.[Formula: see text].