Zopfiellamides C and D, New Decalin-Type Tetramic Acid Derivatives from the Marine-Derived Fungus Aspergillus sp. NF666

Two new decalin-tetramic acid hybrid metabolites, zopfiellamides C (<b>1</b>) and D (<b>2</b>) were isolated from the marine-derived fungus <i>Aspergillus</i> sp. NF666. The structure determination was accomplished on the basis of HRESIMS and NMR spectral data analyses including COSY, HSQC, HMBC, and NOESY experiments. Both isolated metabolites (<b>1</b> and <b>2</b>) exhibited significant growth inhibition against four clinically relevant bacterial strains with minimum inhibitory concentration (MIC) values of about 12.5 μΜ. Moreover, we proposed a plausible biosynthetic pathway of zopfiellamide D (<b>2</b>) in this work.