Tyrothricin
Mixture of gramicidins and tyrocidines from Bacillus brevis used as a topical antimicrobial for throat and skin infections.
Chemical Identity
| Property | Value |
|---|---|
| CAS Number | 1404-88-2 |
| Peptide Class | Peptide Mixture |
| Components | Gramicidins (~20%) + Tyrocidines (~80%) |
| Origin | Aneurinibacillus migulanus |
Structure
Tyrothricin is a natural mixture of gramicidins (linear pentadecapeptides) and tyrocidines (cyclic decapeptides), both produced by Aneurinibacillus migulanus. Tyrocidines contain D-amino acids and a D-phenylalanine at position 1, forming a cyclic decapeptide with antimicrobial activity.
Mechanism of Action
The gramicidin component forms ion channels in bacterial membranes, while tyrocidines act as detergents that disrupt membrane integrity. Together, they provide complementary mechanisms that increase bacterial membrane permeability and cause cell lysis. Activity is primarily against gram-positive bacteria.
Clinical Applications
- Throat infections: Pharyngitis, tonsillitis (lozenges, pastilles)
- Oral infections: Mouthwash for oral cavity infections
- Topical skin infections: Wound infections (limited use)
- Not for systemic use: Toxicity prevents parenteral administration
Pharmacokinetics
- Route: Topical, oral (lozenges), throat application
- Systemic absorption: Minimal with topical/oral use
- Duration: Local antimicrobial effect
Safety and Side Effects
Local irritation, taste disturbance, and potential allergic reactions. Systemic use would cause hemolysis, nephrotoxicity, and neurotoxicity. Well-tolerated for topical and oral use.
References
- Dubos, R.J., & Hotchkiss, R.D. (1941). Tyrothricin. Journal of Experimental Medicine, 73, 661-671.
- Hotchkiss, R.D. (1944). Gramicidin, tyrocidine, and tyrothricin. Advances in Enzymology, 4, 153-199.
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