Pexiganan
Synthetic magainin analog antimicrobial peptide for diabetic foot ulcer infections with broad-spectrum activity.
Chemical Identity
| Property | Value |
|---|---|
| Chemical Formula | C122H210N32O22 |
| Molecular Weight | 2477 Da |
| CAS Number | 147664-64-2 |
| Peptide Class | Synthetic Antimicrobial Peptide |
| Sequence | GIGKFLKKAKKFGKAFVKILKK-NH2 |
Structure
Pexiganan (MSI-78) is a synthetic 22-amino acid amphipathic alpha-helical peptide analog of magainin 2 from the African clawed frog. It is designed with optimized cationic charge and hydrophobicity for enhanced antimicrobial activity and reduced hemolysis compared to the parent peptide.
Mechanism of Action
Pexiganan disrupts bacterial cytoplasmic membranes through its amphipathic helical structure. The cationic residues interact with anionic phospholipids, while the hydrophobic face inserts into the lipid bilayer, forming pores that cause membrane depolarization and cell lysis. It maintains activity against multidrug-resistant organisms.
Clinical Applications
- Diabetic foot ulcers: Topical cream for mild infections (Locrex)
- Wound infections: Broad-spectrum coverage
- Biofilm infections: Activity against biofilm-embedded bacteria
- MDR organisms: Active against MRSA, VRE, and resistant gram-negatives
Pharmacokinetics
- Route: Topical only
- Systemic absorption: Minimal
- Spectrum: Broad (gram-positive, gram-negative, some fungi)
- Formulation: 1% cream (investigational)
Safety and Side Effects
Local irritation, erythema, and mild burning sensation at application site. No systemic toxicity with topical use. Well-tolerated in clinical trials.
References
- Flamm, R.K., et al. (2016). In vitro activity of pexiganan. Antimicrobial Agents and Chemotherapy, 60, 5190-5196.
- Lipsky, B.A., et al. (2008). Pexiganan cream for diabetic foot ulcers. Diabetes Care, 31, 667-672.
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