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 (3 R ,6 R )-bassiatin ( 6 ). The structures of these compounds were determined by 1D, 2D NMR and mass spectrometry. (3 R ,6 R ) - 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 IC 50 values of 7.34 ± 0.20 and 14.54 ± 0.01 μM, respectively, while bassiatin ( 5 ), the diastereomer of compound 6 , was not cytotoxic.