Selective N-actylation of gentamicin antibiotics-synthesis of 1-N-acyl derivatives

Treatment of acid addition salts of aminoglycoside-aminocyclitol antibiotics of the gentamicin-sisomicin class, with one equivalent of triethylamine and an acylating agent results in selective formation of 1-N-acyl derivatives. This is in contrast to acylation of the antibiotic free bases which results in preferential acylation of other basic centres in the molecule. Origins of the observed selectivity are discussed. In vitro antibacterial activities of several new 1-N-acy1 derivatives of gentamicin, sisomicin and verdamicin are reported.