PREPARATION AND EVALUATION OF 3, 4"-ESTER DERIVATIVES OF 16-MEMBERED MACROLIDE ANTIBIOTICS RELATED TO TYLOSIN

A large group of ester derivatives of tylosin-related macrolides was prepared in which the hydroxyl groups at C-3 and C-4" were acylated by either chemical or biochemical methods. Most of the derivatives exhibited excellent in vitro antimicrobial activity. However, only the 3, 4"-diacyl derivatives of tylosin and macrocin showed any significant improvements of in vivo efficacy against experimental infections in rodents.