Butyrolactones from the Fermentation Products of the Endophytic Fungus Aspergillus versicolor

Two new butyrolactones, versicolactones E–F (1 and 2), along with three known butyrolactones (3–5), were isolated from the fermentation products of the endophytic fungus Aspergillus versicolor. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. The anti-tobacco mosaic virus (anti-TMV) activities of 1–5 were evaluated. Compounds 1–5 showed modest anti-TMV activities with inhibition rates of 14.6–18.8%.