Farinosones A−C, Neurotrophic Alkaloidal Metabolites from the Entomogenous Deuteromycete Paecilomyces farinosus

Two new yellow pigments, farinosones A (1) and B (2), were isolated from the mycelial extract of the entomogenous fungal strain Paecilomyces farinosus RCEF 0101, together with farinosone C (3), a new metabolite derived from an early step of pyridone alkaloid biosynthesis. The structures were determined by spectroscopic means, in particular by extensive NMR experiments. Compounds 1 and 3 induced neurite outgrowth in the PC-12 cell line at concentrations of 50 microM, while compound 2 was inactive. No cytotoxicity was observed for compounds 1-3 in PC-12 cells when tested at 50 microM concentration in the MTT assay.