Immune & Antimicrobial
Magainins
Magainins come from the skin of the African clawed frog, and in a tube they are indifferent to the whole catalogue of antibiotic resistance: pexiganan, the synthetic magainin, inhibited 109 isolates — vancomycin-resistant staphylococci and enterococci, KPC, NDM and VIM carbapenemase producers, multidrug-resistant Acinetobacter and Pseudomonas — with no loss of potency against any resistant phenotype. It then went to Phase 3 twice as a cream for infected diabetic foot ulcers, and lost twice. In 835 patients it matched an ordinary ofloxacin tablet rather than beating it, and the US Food and Drug Administration declined it in 1999 on exactly that ground; the repeat placebo-controlled trials in 2016 could not separate the cream from placebo. No naturally occurring magainin has ever been tested in a person.
Last updated
Mechanism
Amphipathic helices bind anionic bacterial membranes, thin the bilayer, and form toroidal pores that lyse the cell.
Reported effects
What sources associate with this compound. Reported categories, not outcomes we have graded — each would need its own citation and rung.
- Topical antibacterial research
- Diabetic ulcer infection trials
- Membrane-active antimicrobial context
Dosing on file unverified
Pexiganan (MSI-78, magainin analog): topical, Phase 3 completed
Carried from a source that labels it unverified, and reproduced with that label attached. A record of what is reported, not a recommendation. No citation on this page establishes it.
Literature on file 3
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in vitro
Membrane Pores Induced by Magainin (Biochemistry 1996, cited 682x) graded on: oriented circular dichroism and pore measurements in model lipid bilayers — read from the abstract — “abstract review”
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in vitro
An Antimicrobial Peptide, Magainin 2, Induced Rapid Flip-Flop of Phospholipids Coupled with Pore Formation and Peptide Translocation (Biochemistry 1996, cited 615x) graded on: fluorescent-lipid flip-flop assays in model vesicles — read from the abstract — “abstract review”
Not graded
1 citation whose study design could not be read from the title. Left ungraded rather than guessed at.
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not graded
NCT00563394: MSI-78 Topical Cream vs. Oral Ofloxacin in the Treatment of Infected Diabetic Ulcers graded on: NCT00563394 is completed and has posted no results - a registration, not a reported outcome — “NCT00563394”
Notes unverified prose
Pexiganan Phase 3 (, NCT00563394) for diabetic foot ulcers; rejected, efficacy not superior; Pexiganan Phase 3 (, NCT00563394)
Not on file 9
8 of the 8 fields we track hold nothing on this record, and each says why. 1 further absence is named below. A blank field is a bug; a named absence is a finding.
- molecular weightnothing we hold supplies it
- molecular formulanothing we hold supplies it
- CAS registry numbernothing we hold supplies it
- PubChem identifiernothing we hold supplies it
- amino-acid sequencenothing we hold supplies it
- SMILES stringnothing we hold supplies it
- InChInothing we hold supplies it
- InChI keynothing we hold supplies it
- half-lifenothing we hold supplies it
Each field links to every other record missing the same thing. The full ledger holds 765 gaps across 163 records.