Bisabolane-type sesquiterpenoids and bacillibactin from the marine-derived fungus Aspergillus sydowii SCSIO 41041 and their enzyme inhibiting activity

Twelve compounds, including eleven bisabolane-type sesquiterpenoids (1 - 11), and one bacillibactin (12) were identified from marine-derived fungus Aspergillus sydowii SCSIO 41041 isolated from Creseis acicula. The chemical structures were elucidated by the basis of spectroscopic evidences, including HRESIMS, NMR and optical rotation. Biologically, all compounds were evaluated for their acetyl cholin-esterase (AChE) enzyme, pancreatic lipase (PL) enzyme, neuraminidase (NA) and phosphodiesterase 4 (PDE4) inhibitory activities. Compound 12 displayed significant inhibitory activity against neuraminidase (NA) with an IC50 value of 24.0 mu M, which was equivalent to the positive drug oseltamivir phosphate (IC50 value of 20.0 mu M). And the NA inhibitory activity was confirmed by molecular docking analysis.