Induced Production of Methyl Bromodihydroxyphenyl Acetates by the Marine-Derived Fungus Aspergillus sp.

摘要

The addition of metal bromides (NaBr and CaBr₂) during fermentation of a marine isolate of the fungus Aspergillus sp. induced production of two new brominated dihydroxyphenylacetic acid derivatives, methyl 2-(6-bromo-3,4-dihydroxyphenyl)acetate ( 1 ) and methyl 2-(2,5-dibromo-3,4-dihydroxyphenyl)acetate ( 2 ), and a known compound, 2-(3,4-dihydroxyphenyl)acetic acid ( 3 ). The structures of the two new compounds ( 1 , 2 ) were assigned through the combination of spectroscopic data analyses and comparison with the spectral data of compound 3 . Compounds 1 – 3 exhibited potent radical-scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) with IC₅₀ values (14.2, 12.1, 11.0?μ m , respectively) demonstrating greater activity than the positive control ( l -ascorbic acid; IC₅₀, 20.0?μ m ).