bacitracin F is a degradation product of the most potent congener, bacitracin A, it shows no bioactivity at all. [4]

Twelve years later, Pavli and Kmetec found the same by comparing the activity of bacitrains B1, B2, B3 and A to their respective oxidative degradation products H1, H2, H3 and F. They also compared the desamido degradation products of bacitracin A, bacitracins Xa and Xa1. Again, the degradation products showed very low bioactivity.

There is little recent research on the toxicity of the individual bacitracin components, and Pavli and Kmetec suggest that “it would be useful to check the credibility of the old and frequently quoted information about nephrotoxicity of the component F if [bacitracin] is used parenterally.”

Understanding the individual congeners, their structures and how they degrade and lose effectiveness can help us store and utilize bacitracin to its fullest potential. Could protecting from and filtering out degradation products could lead to a more effective clinical antimicrobial? TOKU-E looks forward to reading more about the different efficacies and toxicities of bacitracin’s components.


[1] Pavli, V., & Kmetec, V. (2006). Pathways of chemical degradation of Polypeptide antibiotic Bacitracin. Biological & Pharmaceutical Bulletin, 29(11), 2160–2167.

[2] Suleiman, S. A., Song, F., Su, M., Hang, T., & Song, M. (2016). Analysis of bacitracin and its related substances by liquid chromatography tandem mass spectrometry. Journal of Pharmaceutical Analysis.

[3] Ming, L.-J., & Epperson, J. D. (2002). Metal binding and structure–activity relationship of the metalloantibiotic peptide bacitracin. Journal of Inorganic Biochemistry, 91(1), 46–58.

[4] Ikai, Y., Oka, H., Hayakawa, J., Matsumoto, M., Saito, M., Harada, K.-I., … Suzuki, M. (1995). Total structures and Antimicrobial activity of Bacitracin minor components. The Journal of Antibiotics, 48(3), 233–242.