Carbomycin, also known as magnamycin, is a colorless, optically active crystalline[1] macrolide antibiotic with the molecular formula C42H67N O16.

It is derived from the bacterium Streptomyces halstedii and active in inhibiting the growth of Gram-positive bacteria and "certain Mycoplasma strains.

[4] Carbomycin can be isolated from Streptomyces halstedii via extraction from a fermentation broth and purified through crystallization from alcohol-water mixtures.

[9] In 1954, carbomycin was found to be an effective treatment for granuloma inguinale by Harry M. Robinson and Morris M.

[citation needed] Carbomycin stimulates the "accumulation of peptidyl-tRNA in cells at the nonpermissive temperature" of 40˚C in E. coli and thereby inhibits protein synthesis.