Acetylspiramycin

Acetylspiramycin (CAS No.: 24916-51-6) is a 16-membered macrolide antibiotic derived from Streptomyces species and is widely utilized as a biochemical tool for studying bacterial protein synthesis and antimicrobial resistance mechanisms. It exerts its primary activity by binding to the 50S subunit of the bacterial ribosome, thereby inhibiting peptide chain elongation and suppressing protein synthesis. Acetylspiramycin demonstrates in vitro antibacterial activity against a range of Gram-positive organisms and atypical pathogens, including macrolide-resistant Mycoplasma pneumoniae and methicillin-resistant Staphylococcus aureus, with minimum inhibitory concentrations typically observed in the sub-micromolar to low micromolar range depending on the strain and experimental conditions. In addition to its antimicrobial properties, it has been reported to modulate immune-related cellular responses, such as inhibiting lymphocyte transformation and reducing macrophage procoagulant activity, suggesting utility in studies of host–pathogen interactions and immunopharmacology. This compound is commonly applied in microbiological assays, including broth microdilution susceptibility testing, and in cellular models to investigate ribosomal targeting agents and resistance evolution, with working concentrations varying according to assay design and organism sensitivity.