Bioactive Polyketides From the Potato Endophytic Fungus Aspergillus carneus

A previously undescribed polyketide (1) and 3 known analogs (2-4) were obtained from cultures of the potato endophytic fungus Aspergillus carneus. The structures were elucidated on the basis of extensive nuclear magnetic resonance spectroscopic data. The absolute configuration of 1 was further determined by electronic circular dichroism and optical rotation calculations. Compounds 1-4 showed moderate antifungal activity against plant pathogens. Compounds 1, 2, and 4 inhibited nitric oxide production in lipopolysaccharide-stimulated RAW264.7 cells, with half-maximal inhibitory concentration values of 13.36, 30.16, and 51.47 µM, respectively. Compound 4 showed effective antioxidant activity.