Metabolites from the endophytic mitosporic Dothideomycete sp. LRUB20.

The endophytic mitosporic Dothideomycete sp. LRUB20 was found to produce pyrone derivatives, dothideopyrones A-D (1, 3, 4, and 5), together with seven known compounds, including questin (9), asterric acid (10), methyl asterrate (11), sulochrin (12), and eugenitin (13), 6-hydroxymethyleugenitin (14), and cis, trans-muconic acid (15). Dothideopyrone D (5) and its acetate derivative 6 exhibited moderate cytotoxic activity. This is the first report on a naturally occurring muconic acid, which is commonly known as a biomarker in environments after exposure to benzene and phenol (or derivatives). Interestingly, the LRUB20 fungus could produce muconic acid in relatively high yield (47.8mg/L). The utility of endophytic fungi in the field of white biotechnology is discussed.