Structural requirements of benzofuran derivatives dehydro-δ-and dehydro-ε-viniferin for antimicrobial activity against the foodborne pathogen listeria monocytogenes

In a recent study, we investigated the antimicrobial activity of a collection of resveratrol-derived monomers and dimers against a series of foodborne pathogens. Out of the tested molecules, dehydro-δ-viniferin and dehydro-ε-viniferin emerged as the most promising derivatives. To define the structural elements essential to the antimicrobial activity against the foodborne pathogen L. monocytogenes Scott A as a model Gram-positive microorganism, the synthesis of a series of simplified benzofuran-containing derivatives was carried out. The systematic removal of the aromatic moieties of the parent molecules allowed a deeper insight into the most relevant structural features affecting the activity. While the overall structure of compound 1 could not be altered without a substantial loss of antimicrobial activity, the structural simplification of compound 2 (minimal inhibitory concentration (MIC) 16 μµg/mL, minimal bactericidal concentration (MBC) >512 μµg/mL) led to the analogue 7 with increased activity (MIC 8 μµg/mL, MBC 64 μµg/mL).