Two new butyrolactones, versicolactones E-F (1 and 2), along with three known butyrolactones (3)(4)(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%.Aspergillus versicolor is an ubiquitous fungus species commonly isolated from soil, plant debris, marine environments, and indoor air environments >1, 2@. Many metabolites produced by A. versicolor exhibit antibacterial, fungicidal, insecticidal, and cytotoxic properties >3-5@.Butyrolactones are a class of lactones with a four-carbon heterocyclic ring structure, and these compounds are found mainly as metabolites from fungi and higher plants in nature >6@. These compounds appeal to medicinal chemists because of their pronounced pharmacological effects, including antibacterial >7, 8@, cytotoxic >9, 10@, anti-inflammatory >11, 12@, and antiviral >8, 13@ activities.Motivated by a search for new bioactive metabolites from the fermentation products of microbes, the endophytic fungus Aspergillus versicolor was isolated from the rhizome of Paris polyphylla var. yunnanensis, collected in Kunming, Yunnan, P. R. China, and the chemical constituents of its fermentation products were investigated. As a result, two new (1 and 2) and three known butyrolactones (3-5) were isolated. This paper deals with the isolation and structural characterization of these compounds and the anti-tobacco mosaic virus (anti-TMV) activity of compounds 1-5.
