One new nonadride enantiomer, ent-epiheveadride, along with five known dioxopiperazine derivatives were isolated from the marine-derived fungus Aspergillus chevalieri PSU-AMF79. Their structures were identified by extensive spectroscopic analysis. The absolute configuration of ent-epiheveadride was determined by comparison of the specific rotation and electronic circular dichroism data with those of related known compounds. It exhibited antifungal activity against Cryptococcus neoformans ATCC90113 flucytosine-resistant and Candida albicans NCPF3153 with the MIC values of 128 and 200 µg/mL, respectively. In addition, the known L-alanyl-L-tryptophan anhydride displayed TMEM16A inhibitory activity with 65.0% inhibition at a concentration of 5 µg/mL.
Keywords: Aspergillus chevalieri; TMEM16A inhibitory activity; antimicrobial activity; dioxopiperazine; enantiomer; marine-derived fungus; nonadride.