Five new polyketides, including two pairs of enantiomers and a racemate, were isolated from the fermentation broth of Aspergillus fumigatus, an endophytic fungus isolated from Cordyceps sinensis. Their structures were identified using one-dimensional (1D) and two-dimensional (2D) NMR experiments, and the absolute configurations of the enantiomers were confirmed using electronic circular dichroism (ECD) calculations. Compounds 1a and 2a exhibited inhibitory activity against the MV4-11 cell line in vitro, with IC50 values of 23.95 µM and 32.70 µM, respectively.
Keywords: Aspergillus fumigatus; Cordyceps sinensis; ECD calculation; chiral resolution; cytotoxicity; isochromanes.