Induction of secondary metabolite production by fungal co-culture of Talaromyces pinophilus and Paraphaeosphaeria sp

Fungal co-culture is a strategy to induce the production of secondary metabolites by activating cryptic genes. We discovered the production of a new compound, talarodone A (1), along with five known compounds 2–6 in co-culture of Talaromyces pinophilus and Paraphaeosphaeria sp. isolated from soil collected in Miyazaki Prefecture, Japan. Among them, the productions of penicidones C (2) and D (3) were enhanced 27- and sixfold, respectively, by the co-culture. The structure of 3 should be represented as a γ-pyridol form with the reported chemical shifts, but not as a γ-pyridone form, based on DFT calculation.