Biologically active metabolites from the marine isolate of the fungus Myceliophthora lutea

The new compound isoacremine D (1) and acremine A (2) that was previously unknown for marine organisms were isolated from the marine isolate of the fungus Myceliophthora lutea. It was found that acremine A in CHCl 3 was converted through the action of light into spirocompounds called by us spiroacremines A (3) and B (4). The structures of the compounds were elucidated based on NMR spectroscopic and high-resolution mass spectrometric data. The absolute stereochemistry of the spiroacremines was determined by Mosher’s method. It was shown that isoacremine D exhibited antimicrobial activity against Staphylococcus aureus at a concentration of 200 μg/mL and cytotoxic activity against embryos of the sea urchin Strongylocentrotus nudus. It was found that 1–4 exhibited cytotoxic activity against sea urchin sperm cells.