New dihydrobenzofuranoid from the marine-derived fungus Aspergillus ustus KMM 4664

One new dihydrobenzofuran derivative (1), known depsipeptide emericellamide A (2), three known drimanes (3-5) and two artifact drimane derivatives (6, 7) were isolated from the marine-derived fungus Aspergillus ustus KMM 4664. Their structures were determined by detailed analysis of spectroscopic data and by comparison with related known compounds. The absolute configuration of 1 was determined by time-dependent density functional theory (TD-DFT) calculations of ECD spectra. Compound 7 showed significant ability of the inhibition of spermatozoa to fertilize egg-cells of the sea urchin Strongylocentrotus intermedius with IC50 value 21 mu M.

Automated summary

The structures of compounds isolated from marine-derived fungus were determined by spectroscopic data analysis and comparison with related known compounds. Among them, compound 7 showed significant inhibition ability, with an IC50 value of 21 micromolar, in inhibiting the fertilization of sea urchin sperm with egg cells.