A new antifouling tetrapeptide from marine fungus Aspergillus terreus GXIMD00546

In order to clarify the anti-fouling active components of the marine-derived fungal strain Aspergillus terreus GXIMD00546, its fermentation products of the rice medium were isolated by silica gel column chromatography and purified using HPLC. One new compound asperterrestide C (1) and 12 known compounds territrem B (2), methyl-3, 4, 5-trimethoxy-2-(2-(nicotinamido)benzamido)benzoate (3), butyrolactone Ⅰ (4), terrien (5), (1R, 2S)-2-hydroxy-5-oxo-3-((E)-prop-1-en-1-yl)cyclopent-3-en-1-yl acetate (6), (1S, 5R)-5-hydroxy-4-oxo-2-((E)-prop-1-en-1-yl)cyclopent-2-en-1-yl acetate (7), 4-hydroxykigelin (8), monacolin K (9), methyl ester of lactone ring-opened monacolin K (10), butyrolactone Ⅶ (11), aspernolide A (12), and epi-aszonalenin C (13) were identified by the detailed data analysis of NMR sepectra, high-resolution mass spectrometry spectra and the comparison with literatures. The new compound asperterrestide C (1) is a cyclopeptide with rare aminomethylation modifications. Compounds 1-3, 6, 7, 9, 11, 12 showed clear anti-fouling activities against the attachment of barnacle larvae in the EC₅₀ ranges of 0.12-12.5 μg·mL^-1 with low toxicity. Compounds 1, 2, 4, 9-12 also exhibited acetylcholinesterase inhibitory effects with EC₅₀ range of 17.16-55.77 μg·mL^-1. Compounds 4 and 11 have broad spectrum antibacterial activity against human pathogenic bacterium methicillin-resistant Streptococcus aureus (MRSA), and fouling bacteria Methanococcus janaschii (MJ), Vibrio pelagius (VP), and V. Rotiferianus (VR).