Aspergetherins A‐D, New Chlorinated Biphenyls with anti‐MRSA Activity from the Marine Sponge Symbiotic Fungus Aspergillus terreus 164018

Abstract

AbstractAspergetherins A‐D (1–4), four new chlorinated biphenyls, were isolated from the rice fermentation of a marine sponge symbiotic fungus Aspergillus terreus 164018, along with seven known biphenyl derivatives (5–11). The structures of four new compounds were determined by a comprehensive analysis of the spectroscopic data, including HR‐ESI‐MS and 2D NMR data. All 11 isolates were evaluated for their anti‐bacterial activity against two strains of methicillin‐resistant Staphylococcus aureus (MRSA). Among them, compounds 1, 3, 8 and 10 showed anti‐MRSA activity with MIC values of 1.0–128 μg/mL. Preliminary structure‐activity relationship analysis unveiled that both chlorinated substitution and esterification of 2‐carboxylic acid could impact the antibacterial activity of biphenyls.