Structurally diverse sesquiterpenoids and polyketides from a sponge-associated fungus Aspergillus sydowii SCSIO41301

Abstract Five new compounds, including one bisabolane-type sesquiterpenoids, namely aspergillusene D ( 1 ), two new xanthones ( 2 and 3 ), and two new catecholderivatives ( 4 and 5 ), together with fourteen known compounds ( 6 – 19 ), were isolated and identified from the fungus Aspergillus sydowii SCSIO 41,301 from the sponge Phakellia fusca . Their structures and absolute configurations were determined by extensive spectroscopic analysis and electronic circular dichroism (ECD) calculations. Most of the isolated compounds ( 1 – 3 , and 6 – 19 ) were evaluated for their antiviral, cytotoxic, and antibacterial activities. Among them, new compounds 2 and 3 displayed obvious selective inhibitory activities against two influenza A virus subtypes, including A/Puerto Rico/8/34 (H1N1) and A/FM-1/1/47 (H1N1), with IC 50 values ranging from 2.17 ± 1.39 to 4.70 ± 1.11 μM.