Seven cyclic depsipeptides, including two new cyclic pentadepsipeptides avenamides A (1) and B (2), were isolated from a plant-derived fungus Fusarium avenaceum W8 by using the bioassay-guided fractionation method. The planar structures were elucidated by using comprehensive spectroscopic analyses, including 1D and 2D NMR, as well as MS/MS spectrometry. The absolute configuration of the amino acid and hydroxy acid residues was confirmed by using the advanced Marfey's method and chiral HPLC analysis, respectively. Compounds 1-7 were evaluated for their cytotoxic activities against A549 and NCI-H1944 human lung adenocarcinoma cell lines and their antimicrobial activities against Staphylococcus aureus and Saccharomyces cerevisiae. As a result, compounds 1-4 showed moderate cytotoxicity, with IC50 values of 6.52~45.20 µM. Compounds 1 and 3 exhibited significant antimicrobial activities against S. aureus and S. cerevisiae, with an MIC80 of 11.1~30.0 µg/mL.
Keywords: Fusarium avenaceum W8; antimicrobial activity; cyclic depsipeptides; cytotoxic activity; endophytic fungus.