Streptomyces erythraeus Erythromycin

Flurithromycin (120), a fluorinated erythromycin macrolide, has been isolated from a mutant strain of Streptomyces erythraeus. It shows antibacterial activity against Streptococcus pneumoniae (MIC 0.0015-... 

Dhillon, N., Hale, R. S., Cortes, J., and Leadlay, P. F. (1989). Molecular characterization of a gene from Saccharopolyspora erythraea (Streptomyces erythraeus) which is involved in erythromycin biosynthesis. Mol. Microbiol. 3, 1405-1414. 

Erythromycins. A shunt metabolite of erythromycin biosynthesis has been isolated from the ferQientation broth of a block mutant of Streptomyces erythraeus, and structure (107) was determined for the compound... 

Erythromycin is a macrolide antibiotic isolated from Streptomyces erythraeus. It has a similar spectmm of activity to that of the early penicillins and was therefore often used as a substimte in patients who displayed life-threatening penicillin allergies. Erythromycin is a base, where the aliphatic tertiary amino group has a pKa of 8.8. Despite this, oral preparations are difficult to formulate because the tertiary alcohols at the 6 and 12 positions cause instability in stomach add. As with many tertiary alcohols in strong add, the C-OH bond can break to form highly reactive carbonium ions, in this case at dther the 6 or 12 positions. An intramolecular cydisation via the carbonyl oxygen at C-10 with the electrophilic carbonium ions results in formation of the inactive eiythralosamine (Fig. 8.15). 

---