Erythromycin series. XII. Antibacterial in vitro evaluation of 10-dihydro-10-deoxo-11-azaerythromycin A: synthesis and structure-activity relationship of its acyl derivatives.

Antibacterial in vitro evaluation of 10-dihydro-10-deoxo-11-azaerythromycin A (5), the new 15-membered semi-synthetic macrolide antibiotic with nitrogen as additional atom in the aglycone ring of erythromycin A (1), was reported. Although amine (5) and its 13,14-cyclic carbonate (14) were less active than 1 against erythromycin-sensitive Staphylococcus aureus strains they showed advantageous properties against Gram-negative test organisms and clinical isolates. Also, a large number of acyl derivatives of 5 were synthesized and evaluated. N-11 monoacyl compounds exhibited 2 to 50 times lower in vitro antibacterial efficacy than the parent amine (5).