Abstract
Several derivatives of spiramycin (I)-hydrogenation products and esters-were prepared to improve this antibiotic. Antibacterial activity and acid stability of the derivatives were tested. New acyl derivatives, which were prepared by acid anhydride and pyridine at relatively high temperature, showed different n. m. r. spectrum from that of spiramycin. They are designated tentatively as acyl derivatives of isospiramycin which showed remarkable resistance against acid hydrolysis.
