New Broad-Spectrum Antibacterial Amphiphilic Aminoglycosides Active against Resistant Bacteria: From Neamine Derivatives to Smaller Neosamine Analogues

Aminoglycosides (AGs) constitute a major family of potent and broad-spectrum antibiotics disturbing protein synthesis through binding to the A site of 16S rRNA. Decades of widespread clinical use of AGs strongly reduced their clinical efficacy through the selection of resistant bacteria. Recently, conjugation of lipophilic groups to AGs generated a novel class of potent antibacterial amphiphilic aminoglycosides (AAGs) with significant improved activities against various sensitive and resistant bacterial strains. We have identified amphiphilic 3′,6-dialkyl derivatives of the small aminoglycoside neamine as broad spectrum antibacterial agents targeting bacterial membranes. Here, we report on the synthesis and the activity against sensitive and resistant Gram-negative and/or Gram-positive bacteria of new amphiphilic 3′,4′-dialkyl neamine derivatives and of their smaller analogues in the 6-aminoglucosamine (neosamine) series prepared from N-acetylglucosamine.