A new acyclic peroxide from Aspergillus nidulans SD-531, a fungus obtained from deep-sea sediment of cold spring in the South China Sea

A new acyclic peroxide derivative asperoxide A (1), along with 13 known compounds, namely, microperfuranone (2), 9-hydroxymicroperfuranone (3), gibellulin A (4), lecanoric acid (5), terrequinone A (6), sterigmatocystin (7), isosecosterigmatocystin (8), arugosin C (9), curvularin (10), 3,3′-diindolylmethane (11), austinol (12), austin (13), and dehydroaustin (14), were isolated and identified from the culture extract of Aspergillus nidulans SD-531, a fungus obtained from the deep-sea sediment of cold spring in the South China Sea. Their structures were determined based on detailed interpretation of nuclear magnetic resonance (NMR) spectroscopic and mass spectrometry data analysis. All the isolated compounds were evaluated for antimicrobial activities against human and aquatic bacteria as well as plant pathogenic fungi. Compounds 1-28, 10, and 11 exhibited antimicrobial activities against some of the tested strains with minimum inhibitory concentration (MIC) values ranging from 2 to 64 μg/mL. Compounds 4 and 6 displayed strongest activities among the tested samples and might be used as promising molecules for the development of natural antimicrobial agents.