Bioassay-guided fractionation of an organic extract of the broth from the marine-derived fungus of the genus Aspergillus led to the isolation of the polyketides, (+)-epoxydon (1), (+)-epoxydon monoacetate (2), gentisyl alcohol (3), 3-chlorogentisyl alcohol (4), and methylhydroquinone (5). Compounds 1-5 showed a potent antibacterial activity against the methicillin-resistant and multidrug-resistant Staphylococcus aureus (MRSA and MDRSA) with MIC (minimum inhibitory concentration) values of 12.5, 12.5, 12.5, 50.0, and $6.2;{mu}g/mL$, respectively. Compounds 1-4 also exhibited a significant radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) with $IC_{50}$ values of 6.0, 15.0, 7.0, and $1.0;{mu}M$, respectively.