Aristolochene is a bicyclic sesquiterpene produced by certain fungi including the cheese mold Penicillium roqueforti. It is biosynthesized from farnesyl pyrophosphate by aristolochene synthase and is the parent hydrocarbon of a large variety of fungal toxins. Aristolochene is a bicyclic sesquiterpene produced by certain fungi including the cheese mold Penicillium roqueforti. It is biosynthesized from farnesyl pyrophosphate by aristolochene synthase and is the parent hydrocarbon of a large variety of fungal toxins. The substance was first isolated from Penicillium roqueforti, a fungus used to make blue cheeses like Roquefort, Danish Blue, Stilton cheese and Gorgonzola. Aristolochene is a precursor to the toxin known as PR toxin, made in large amounts by Penicillium roqueforti. PR-toxin has been implicated in incidents of mycotoxicoses resulting from eating contaminated grains.