Secondary metabolites from the cold-seep-derived fungus Penicillium sp. SCSIO 41425 and their free radical scavenging activity

To study the chemical compositions from Penicillium sp. SCSIO 41425 and explore their DPPH radical scavenging activity. Ethyl acetate extract of Penicillium sp. SCSIO 41425 was separated and purified by silica gel, Ostade-cylsilane (ODS), semi-preparative HPLC, and thin layer chromatography, and their structures were determined by spectroscopic analysis and comparison with the reported literatures. A total of 18 compounds were isolated from Penicillium sp. SCSIO 41425, including one new compound, (2′ R ,3′ R )-4-(3-hydroxybutan-2-yl)-3,6-dimethylbenzene-1,2-diol ( 1 ) and seventeen known compounds ( 2 – 18 ). Their structures were elucidated by detailed NMR and ECD calculations. Compounds 4 and 5 exhibited potent DPPH radical scavenging activity, with EC 50 values of 8.42 and 6.62 ​μg/mL, which were stronger than the positive control ascorbic acid (EC 50 , 11.22 ​μg/mL). This study expands the natural product library of marine cold-seep-derived fungus and provides marine-derived drug source molecules for potent antioxidants.