Aspernolides L and M, new butyrolactones from the endophytic fungus Aspergillus versicolor.

During the systematic search of active compounds from endophytic fungi, two new butyrolactones, namely aspernolides L (2) and M (4), together with four known compounds: 1-O-acetylglycerol (1), butyrolactone I (3), butyrolactone VI (5), and (+) alantrypinone (6) were characterized from the EtOAc extract of the endophytic fungus Aspergillus versicolor isolated from the roots of Pulicaria crispa (Asteraceae). Extensive spectroscopic analysis, including 1D, 2D NMR, and HRESIMS, was used to elucidate their structures. Compounds 1, 5, and 6 are reported for the first time from this fungus.