MICROBIAL CONVERSION OF ANTIBIOTICS. I: DEACYLATION OF MARIDOMYCIN BY BACTERIA

Maridomycin, a macrolide antibiotic, was hydrolyzed to 4"-deacylmaridomycin byesterases obtained from many bacteria. Among these bacteria, Bacillus megaterium91277 showed the highest activity. The properties of the esterase were investigated by using cell-free extract obtained from B. megaterium 91277. Optimum pH was 8.5.9-Propionylmaridomycin was also hydrolyzed to 4"-deacyl-9-propionylmaridomycin by the esterase. The hydrolytic rate of 9-propionylmaridomycin was more rapid than that of maridomycin. Substrates bearing 4"-acyl group of C3 or C4 were most rapidly hydrolyzed. 4"-Depropionylmaridomycln III and 4"-depropionyl-9-propionylmaridomycin III were prepared from maridomycin III and 9-propionylmaridomycin III, respectively, in large scale by using culture broth of B. megaterium 91277. 4"-DeisovaIeryljosamycin