A novel method to prepare guanidine substituted aminoglycoside derivatives was developed.Free guanidine reacted with Cbz-protected aminoglycosides to produce guanidinylcarbonyl substituted derivatives.A methoxycarbonyl-protected intermediate was isolated,and the mechanism of guanidinylcarbonyl modification was proposed.With this method,six per- or part-guanidylcarbonyl substituted aminoglycosides were successfully obtained in good yields.Their in vitro antibacterial activities were essayed.
