Chlorinated metabolites with antibacterial activities from a deep-sea-derived fungus.

Chromatographic separation of the solid cultures of a deep-sea-derived fungus (MCCC 3A00308) resulted in the isolation of eight compounds. Their structures were identified on the basis of the spectroscopic data. Compounds 1-8 are classified as depsidone-type (1-4), isocoumarin-type (5 and 6), and benzothiazole-type (7 and 8), of which 1-7 are new compounds and 1-3 along with 5 and 6 are chlorinated. Compound 3 is characterized by trichlorination and shows potent activities against Gram-positive pathogenic bacteria including ATCC 25923, ATCC 10792, and CMCC 63501, with minimum inhibitory concentration (MIC) values ranging from 0.5 to 1.0 μg mL. This study extends the chemical diversity of chlorinated natural products from marine-derived fungi and provides a promising lead for the development of antibacterial agents.