Depsidones, aromatase inhibitors and radical scavenging agents from the marine-derived fungus aspergillus unguis CRI282-03

Abstract

Three new depsidones (1, 3, and 4), a new diaryl ether (5), and a new natural pyrone (9) (synthetically known), together with three known depsidones, nidulin (6), nornidulin (7), and 2-chlorounguinol (8), were isolated from the marine-derived fungus Aspergillus unguis CRI282-03. Aspergillusidone C (4) showed the most potent aromatase inhibitory activity with the ICvalue of 0.74 μM, while depsidones 1, 3, 6-8 inhibited aromatase with ICvalues of 1.2-11.2 μM. It was found that the structural feature of depsidones, not their corresponding diaryl ether derivatives (e.g. 5), was important for aromatase inhibitory activity. Aspergillusidones A (1) and B (3) showed radical scavenging activity in the XXO assay with ICvalues of 16.0 and < 15.6 μM, respectively. Compounds 1 and 3-7 were mostly inactive or showed only weak cytotoxic activity against HuCCA-1, HepG2, A549, and MOLT-3 cancer cell lines. © 2012 Georg Thieme Verlag KG Stuttgart. New York.