Prenylated Isocoumarins from the Fermentation Products of the Endophytic Fungus Aspergillus versicolor and Their Anti-Tobacco Mosaic Virus Activities

Two new prenylated isocoumarins, versicolols C and D ( 1 and 2 ), together with three known isocoumarins ( 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 compounds 1 and 2 were evaluated. The results revealed that compounds 1 and 2 showed moderate anti-TMV activity with inhibition rates of 22.4 and 24.6%, respectively.