Metabolites produced by Gnomoniopsis castanea associated with necrosis of chestnut galls

In this manuscript, we report the isolation and characterization of two secondary metabolites produced by a Gnomoniopsis castanea strain isolated in the Campania region (Italy) from chestnut galls infested with Dryocosmus kuriphilus. The compounds, purified from the fungal culture filtrate by using preparative HPLC-DAD, showed the same spectroscopic data of abscisic acid and 1?,4?-diol of abscisic acid. Phytotoxic activity of the isolated metabolites on chestnut leaves has been also observed.