Secondary metabolites from the Cordyceps-colonizing fungus Aspergillus versicolor ZJUTE2.

Two new polyketides versicolorones A-B (1 – 2), one new diketopiperazine derivative aspergiamide B methyl ester (3), along with twenty known compounds 4 – 23 , were obtained from the EtOAc extract of the Cordyceps -colonizing fungus Aspergillus versicolor ZJUTE2. The structures of 1 – 3 were established by detailed interpretation of the spectroscopic data and their absolute configurations were established by comparative analyses of the calculated and experimental ECD spectra. In the in-vitro bioassay, compounds 8 and 21 exhibited significant inhibitory activity against the Escherichia coli β -glucuronidase (EcGUS) with IC 50 values of 54.73 ± 2.69 and 56.59 ± 1.77 μM, respectively. [Display omitted] [ABSTRACT FROM AUTHOR]