spiramycin iii

Spiramycin III is an antibiotic within the erythromycin carbomycin group of compounds.

Neospiramycin I is a macrolide antibiotic and derivative of spiramycin I.1It is active against the macrolide-sensitive KB210, but not the macrolide-resistant KB224, strain ofS. aureus(MICs = 3.12 and >100 μg/ml, respectively), as well asB. cereus,B. subtilis,M. luteus,E. coli, andK. pneumoniae(MICs = 1.56, 3.12, 3.12, 0.2, 50, and 12.5 μg/ml, respectively). Neospiramycin I binds toE. coliribosomes with an IC50value of 1.2 μM. It protects against mortality in a mouse model ofS. pneumoniaetype III infection (ED50= 399.8 mg/kg).2