Chemical modification of antibiotic eremomycin at the asparagine side chain.

AA3-Carboxyeremomycin 2, obtained by selective hydrolysis of antibiotic eremomycin was used as a starting compound for the eremomycin chemical modifications at the asparagine side chain to be transformed into eremomycin AA3, AA7 bis-amides (3a∼c). Bis-benzylamide 3b displayed an activity (8 μg/ml) against an E. faecium VanA strain.