Asptertides A-H, C13-Polyketides From a Marine-Derived Aspergillus terreus.

Abstract

In the present study, 11 C₁₃-polyketides comprising a monocyclic skeleton of an aromatic (1-6 and 11) or a cyclohexanone moiety (7) and an oxygenated bicyclic nucleus (8-10) were isolated from a mutated strain of endophytic fungus Aspergillus terreus RA2905. Five pairs of enantiomers (2a/b-5a/b and 7a/b) were achieved by chiral-phase HPLC separation. The structures of previously unreported asptertides A-H (1-8) were determined by analysis of the spectroscopic data and electronic circular dichroism (ECD) calculations. 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging bioassays revealed that some compounds showed moderate antioxidant effects, with IC₅₀ values ranging from 13.7 to 35.6 µM.