Bioactive aromatic butenolides from a mangrove sediment originated fungal species, Aspergillus terreus SCAU011

Seven new compounds including five aromatic butenolide analogues ( 1–5 ), one quinazolinone alkaloid ( 6 ) and one benzoic acid derivative ( 7 ), along with eleven known co-metabolites ( 8–18 ), were isolated from Aspergillus terreus SCAU011, a fungus from the rhizosphere sediment of a mangrove plant Rhizophora stylosa. The structures of these isolates were established by a combination of MS, NMR and ECD data analyses, as well as chemical method. Compound 3 is a rare ring-open aromatic butenolide, while 6 represents the first natural ring-open benzomalvin-type quinazolinone alkaloid. Also, the previously reported structures for asperlides A–C were proposed to be revised in the present work. The COX-2 inhibitory, α-glucosidase inhibitory, antioxidant and antibacterial activities of all the compounds were assessed. While compounds 4, 6, 11 and 18 exhibited better COX-2 inhibitory activity than the positive control celecoxib, compounds 9 and 10 showed significant α-glucosidase inhibitory activity with IC 50 values of 56.1 and 12.9 μM, respectively. Meanwhile, half of the tested samples ( 1, 8–11 and 15–17 ) exerted similar or better antioxidant activity compared with the reference drug curcumin, and compounds 3, 9, 17 and 18 displayed moderate antibacterial effect against Staphylococcus aureus.