Four new polyketides have been identified in culture filtrates of the fungal strain Penicillium sp. IBWF104-06 isolated from a soil sample. They are structurally based on the same trans-decalinpentanoic acid skeleton as tanzawaic acids A-H. One of the new compounds was found to inhibit the conidial germination in the rice blast fungus Magnaporthe oryzae at concentrations of 25 μg/mL.
Keywords: arohynapene; natural products; polyketides; structure elucidation; tanzawaic acid.