Biotransformation of the Trichoderma metabolite 6-n-pentyl-2H-pyran-2-one (6PAP) by selected fungal isolates

A variety of fungi were tested for their ability to transform the antifungal Trichoderma metabolite 6-n-pentyl-2H-pyran-2-one (6PAP) (1). Three Penicillium isolates, a Sclerotinia isolate, and a Fusarium isolate were all able to rapidly metabolize I and gave mixtures of isomers of monohydroxylated 1 and, in some cases, products resulting from further oxidation to carboxylic acids. Among these products were four previously unidentified metabolites (6, 7, 8, and 9) which were isolated and characterized by NMR spectroscopy. Sphaeropsis sapinea, Ophiostoma quercus, Ophiostoma piceae, a Verticillium sp., and two additional Fusarium isolates were unable to metabolize 1 efficiently.