Epigenetic Manipulation Induces the Production of Coumarin-Type Secondary Metabolite from Arthrobotrys foliicola

Pursuing epigenetic manipulation approach in fungi led to the isolation of an unusual coumarin metabolite from fungi. An addition of the histone deacetylase inhibitor, suberohydroxamic acid (SBHA), to the culture medium of Arthrobotrys foliicola induced production of the coumarin-type secondary metabolite represented by a single intensive peak in the HPLC profile of the ethyl acetate extract. The compound which was identified as 4-ethyl-7-hydroxy-8-methyl-2H-chromen-2-one (1) was isolated from nature for the first time. Moreover, the investigation on the remaining part of the HPLC profile led to the separation of 6-ethyl-2,4-dihydroxy-3-methylbenzaldehyde (2) and ten 2,5-diketopiperazine compounds (3–12). The structures of isolates were deduced by their mass and NMR spectroscopic data. The coumarin-type secondary metabolite (1) with peculiar smell induced by epigenetic stimulation is found for the first time in the Arthrobotrys species and the family Orbiliaceae. We evaluated 1 for the cytotoxic, anti-inflammatory, anti-allergic and nematocidal activities, however, it was found inactive.