Secondary Metabolites from Mariana Trench-Derived Penicillium sp. SCSIO41052 and Their Antimicrobial Activity

Compared to terrestrial environments, marine ecosystems are characterized by dynamic environmental conditions such as temperature, salinity, pressure. As major producers of marine natural products, marine-derived fungi thrive in these extreme habitats, leading to produce secondary metabolites with unprecedented chemical structures and unique bioactivities. In this study, two new linear N-acetylpeptides (1 and 2) and one new long-chain carboxylic acid (3) along with fifteen known compounds were isolated from Penicillium sp. SCSIO41052 separated from Mariana Trench sediment. Their structures were elucidated through spectroscopic analysis. Marfey’s analysis of the hydrolysate of 1 was performed to determine the absolute configurations of its amino acid residues. By comparing the ECD curves of 1 and 2, it can be concluded that they have identical absolute configurations. The activity screening indicated that eight compounds (3, 4, 5, 6, 10, 12, 13 and 18) exhibited antimicrobial activity. Notably, compound 13 exhibited varying levels of antimicrobial activity against six pathogenic strains with Minimum Inhibitory Concentration (MIC) values ranging from 0.5 to 64 μg/mL, highlighting its potential antimicrobial properties. Moreover, compound 2 displayed moderate cytotoxic activity against the PC3 cell line. Compound 5 showed weak acetylcholinesterase (AchE) inhibition. These findings not only enriched the chemical structural diversity of secondary metabolites from marine fungi but also explored potential bioactive molecules, thereby laying a foundation for further research on marine medicinal resources.