Thiostrepton from Streptomyces azureus

Thiostrepton is a macrocyclic polypeptide antibiotic that is structurally different from vancomycin and teicoplanin. It is soluble in water and acetic acid. It is obtained from Streptomyces azureus bacterium. There are 17 chiral centers in this antibiotic, with 2 large cavities (A and B in Fig. 1). Five thiazole rings, 1 quinoline ring, 5 hydroxyl groups, 10 amide linkages, and 1 secondary amine make the molecule stereo-specific in nature. 

The thiostrepton family of peptide antibiotics was first isolated from the culture broth of Streptomyces azureus <2002TL105>. Similarily, sulfomycin I was originally isolated from Streptomyces viridchromogenes MCRL-0368 <2004CL72>. 

Thiostrepton, an important member of the thiopeptide antibiotics because of its biological and medical value. It was first isolated as early as 1954 from Streptomyces azureus. It is used in animal health care as a topical antibiotic. However, its application in humans is limited by its low solubility and bioavaUability which led to development of drug resistance by the proliferating bacteria. The total synthesis was described in 2005 [Y. Xing, D. F. Draper, Biochemistry 1996, 35, 1581 K. C. Nicolaou etal.,J. Am. Chem. Soc. 2005, 127, 11159]. 

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