Three new heptapeptides isolated from the coral-derived fungus Aspergillus candidus SCSIO 41234

Three previously undescribed GABA-containing heptapeptides, named unguisins P-R (1-3), were obtained from the deep-sea-derived fungus Aspergillus candidus SCSIO 41234. Their structures were elucidated by extensive spectroscopic analysis, including 1D and 2D NMR, HR-ESI-MS, and Marfey's method. Bioassay results indicated that all three compounds exerted significant pancreatic lipase (PL) inhibitory activity, while compounds 2 and 3 exhibited weak antioxidant activity. In silico docking studies further revealed the promise of these molecules as PL inhibitors, with the analysis uncovering distinctive interaction modes between the compounds and their protein targets.