New indole diketopiperazine from the fungus Penicillium chrysogenum.

A new indole diketopiperazine penichrysogenone A (1), and two new natural products 4-(N-benzoyl-N-hydroxyamino)-butyric acid (2) and 2-acetamido-N-benzyl-2-(ethylamino)acetamide (3), together with 10 known compounds (4-13) were isolated from the fungus Penicillium chrysogenum wis54-1255. The structure of new compound was determined by the extensive spectroscopic analyses and ECD calculations. Bioactivity assays revealed that compound 4 showed antibacterial activity against Pseudomonas solanacearum (MIC = 64 μg/mL), while compound 10 exhibited antifungal activity against Candida auris (MIC = 32 μg/mL). Furthermore, compounds 2 and 10 displayed potent ABTS radical scavenging activity, superior to that of the positive control ascorbic acid.