New Benzofuranoids and Phenylpropanoids from the Mangrove Endophytic Fungus, <i>Aspergillus</i> sp. ZJ-68

Abstract

Three new benzofuranoids, asperfuranoids A−C (1−3), two new phenylpropanoid derivatives (6 and 7), and nine known analogues (4, 5, and 8−14) were isolated from the liquid substrate fermentation cultures of the mangrove endopytic fungus Aspergillus sp. ZJ-68. The structures of the new compounds were determined by extensive spectroscopic data interpretation. The absolute configurations of 1−3 were assigned via the combination of Mosher’s method, and experimental and calculated electronic circular dichroism (ECD) data. Compounds 4 and 5 were a pair of enantiomers and their absolute configurations were established for the first time on the basis of their ECD spectra aided with ECD calculations. All isolated compounds (1−14) were evaluated for their enzyme inhibitory activity against α-glucosidase and antibacterial activities against four pathogenic bacteria (Staphylococcus aureus, Escherichia coli, Bacillus subtilis, and Pseudomonas aeruginosa). Among them, compound 6 exhibited potent inhibitory activity against α-glucosidase in a standard in vitro assay, with an IC50 value of 12.4 μM, while compounds 8 and 11 showed activities against S. aureus, E. coli, and B. subtilis, with MIC values in the range of 4.15 to 12.5 μg/mL.

Keywords

• benzofuranoids
• phenylpropanoids
• <i>Aspergillus</i> sp.
• <i>α</i>-glucosidase
• antibacterial activity