Secondary Metabolites from the Marine-Derived Fungus Dichotomomyces sp. L-8 and Their Cytotoxic Activity

摘要

Bioassay-guided isolation of the secondary metabolites from the fungus Dichotomomyces sp. L-8 associated with the soft coral Lobophytum crassum led to the discovery of two new compounds, dichotones A and B (>1 and >2), together with four known compounds including dichotocejpin C (>3), bis-N-norgliovictin (>4), bassiatin (>5) and (3R,6R)-bassiatin (>6). The structures of these compounds were determined by 1D, 2D NMR and mass spectrometry. (3R,6R)-bassiatin (>6) displayed significant cytotoxic activities against the human breast cancer cell line MDA-MB-435 and the human lung cancer cell line Calu3 with IC50 values of 7.34 ± 0.20 and 14.54 ± 0.01 μM, respectively, while bassiatin (>5), the diastereomer of compound >6, was not cytotoxic.