The use of aminoglycoside derivatives to study the mechanism of aminoglycoside 6′-N-acetyltransferase and the role of 6′-NH2 in antibacterial activity

Aminoglycoside antibiotics act by binding to 16S rRNA. Resistance to these antibiotics occurs via drug modifications by enzymes such as aminoglycoside 6′-N-acetyltransferases (AAC(6′)s). We report here the regioselective and efficient synthesis of N-6′-acylated aminoglycosides and their use as probes to study AAC(6′)-Ii and aminoglycoside-RNA complexes. Our results emphasize the central role of N-6′ nucleophilicity for transformation by AAC(6′)-Ii and the importance of hydrogen bonding between 6′-NH2 and 16S rRNA for antibacterial activity.