Katanosins

Katanosins are a group of antibiotics (also known as lysobactins). They are natural products with strong antibacterial potency.^[1] So far, katanosin A and katanosin B (lysobactin) have been described.

Additional recommended knowledge

Weighing the right way

Essential Laboratory Skills Guide

What is the Correct Way to Check Repeatability in Balances?

Sources

Katanosins have been isolated from the fermentation broth of microorganisms, such as Cytophaga^[2] or the Gram-negative bacterium Lysobacter sp.^[3].

Structure

Katanosins are cyclic depsipeptides (acylcyclodepsipeptides). These proteinogenic structures are not regular proteins from primary metabolism. They origin from the bacterial secondary metabolism. Accordingly, various non-proteinogenic (non-ribosomal) amino acids are found in katanosins, such as 3-hydroxyleucine, 3-hydroxyasparagine, allo-threonine and 3-hydroxyphenylalanine. All katanosins have a cyclic and a linear segment (“lariat structure”). The peptidic ring is closed with an ester bond (lactone). Katanosin A and B differ in the amino acid position 7. The minor metabolite Katanosin A has a valin in this position, whereas the main metabolite katanosin B carries an isoleucine.

Biological Activity

Katanosin antibiotics target the bacterial cell wall biosynthesis. They are highly potent against problematic Gram-positive hospital pathogens such as staphylococci and enterococci. Their promising biological activity attracted various biological and chemical research groups. Their in-vitro potency is comparable with the current “last defence” antibiotic vancomycin.

Chemical Synthesis

The first total syntheses of katanosin B (lysobactin) have been described in 2007.^[4][5]

References

1. ^ D. P. Bonner, J. O´Sullivan, S. K. Tanaka, J. M. Clark, R. R. Whitney, J. Antibiot. 1988, 41, 1745–1751 PMID 3209466
2. ^ J. O´Sullivan, J. E. McCullough, A. A. Tymiak, D. R. Kirsch, W. H. Trejo, P. A. Prinicipe, J. Antibiot. 1988, 41, 1740–1744 PMID 3209465
3. ^ J. I. Shoji, H. Hinoo, K. Matsumoto, T. Hattori, T. Yoshida, S. Matsuura, E. Kondo, J. Antibiot. 1988, 41, 713–718 PMID 3403364
4. ^ F. von Nussbaum, S. Anlauf, J. Benet-Buchholz, D. Häbich, J. Köbberling, L. Musza, J. Telser, H. Rübsamen-Waigmann, N. A. Brunner Angew. Chem. 2007, 119, 2085–2088; Angew. Chem. Int. Ed. 2007, 46, 2039–2042 PMID 17211904
5. ^ A. Guzman-Martinez, R. Lamer, M. S. VanNieuwenhze, J. Am. Chem. Soc. 2007, 129, 6017–6021 PMID 17432854