Two new polyketides, penicilloxalones A (1) and B (2), together with 13 known compounds (3-15), were isolated from the ethyl acetate extract of the solid substrate fermentation cultures of the fungus Penicillium oxalicum MHZ153. The structures of the isolates were determined by spectroscopic analysis and comparison of their spectroscopic and physicochemical data with the literature values. Compounds 7 and 11 showed inhibition of nitric oxide production in lipopolysaccharide-stimulated BV-2 microglial cells with IC values of 0.9 ± 0.2 μM and 87.9 ± 0.7 μM, respectively.