Isolation, structural elucidation, and biological activity of a novel isocoumarin from the dark septate endophytic fungus Phialocephala fortinii.

A novel isocoumarin was isolated from the mycelia of the dark septate endophytic fungus Phialocephala fortinii. The chemical structure was determined to be 8-hydroxy-6-methoxy-3,7-dimethyl-1H-2-benzopyran-1-one based on mass spectrometry, 1H-nuclear magnetic resonance (NMR), and 13C-NMR spectroscopic analyses, including 2D-NMR experiments. The isolated compound inhibited root growth of Arabidopsis thaliana, suggesting its potential as a plant growth regulator.