Dong-Lin Zhao

Two new naphthalenones, corynenones A and B (1 and 2), and one new depsidone, corynesidone E (3), together with one known depsidone, corynesidone A (4) and two known diphenyl ethers, corynethers A (5) and B (6), were isolated from the sponge-derived fungus Corynespora cassiicola XS-20090I7. Their structures including absolute configurations were determined by spectroscopic data and electronic circular dichroism (ECD) spectra. Compounds 4 and 5 showed cytotoxicity against human promyelocytic leukemia HL-60 and human cervical carcinoma HeLa cell lines.

One new phenylalanine derivative 4′-OMe-asperphenamate (1), along with one known phenylalanine derivative (2) and two new cytochalasins, aspochalasin A1 (3) and cytochalasin Z24 (4), as well as eight known cytochalasin analogues (5–12) were isolated from the fermentation broth of Aspergillus elegans ZJ-2008010, a fungus obtained from a soft coral Sarcophyton sp. collected from the South China Sea. Their structures and the relative configurations were elucidated using comprehensive spectroscopic methods. The absolute configuration of 1 was determined by chemical synthesis and Marfey’s method. All isolated metabolites (1–12) were evaluated for their antifouling and antibacterial activities. Cytochalasins 5, 6, 8 and 9 showed strong antifouling activity against the larval settlement of the barnacle Balanus amphitrite, with the EC₅₀ values ranging from 6.2 to 37 μM. This is the first report of antifouling activity for this class of metabolites. Additionally, 8 exhibited a broad spectrum of antibacterial activity, especially against four pathogenic bacteria Staphylococcus albus, S. aureus, Escherichia coli and Bacillus cereus.