Structure−Activity Relationships of Polymyxin Antibiotics
نویسندگان
چکیده
منابع مشابه
Paenibacillus polymyxa PKB1 produces variants of polymyxin B-type antibiotics.
Polymyxins are cationic lipopeptide antibiotics active against many species of Gram-negative bacteria. We sequenced the gene cluster for polymyxin biosynthesis from Paenibacillus polymyxa PKB1. The 40.8 kb gene cluster comprises three nonribosomal peptide synthetase-encoding genes and two ABC transporter-like genes. Disruption of a peptide synthetase gene abolished all antibiotic production, wh...
متن کاملStudies on Polymyxin: Isolation and Identification of Bacillus polymyxa and Differentiation of Polymyxin from Certain Known Antibiotics.
Polymyxin is an antibiotic substance occurring in the culture filtrates of Bacillus polymyxa. The isolated substance is unique in its specificity for gram-negative bacteria. A summary of the more important results obtained during the course of several years, including chemotherapeutic and toxicity data, has been reported (Stansly, Shepherd, and White, 1947). The present contribution is concerne...
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Polymyxin B nonapeptide, derived by cleavage of the fatty acyl diaminobutyric acid from polymyxin B, is considerably less toxic, lacks bactericidal activity, and retains its ability to render gram-negative bacteria susceptible to several antibiotics by permeabilizing their outer membranes. The peptide rendered all 53 polymyxin-susceptible strains tested more susceptible to novobiocin, lowering ...
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Interesting synergism in vitro between a recently introduced antibiotic, colistin methane sulphonate, and sulphonamide drugs is described. The observations were extended to polymyxin B sulphate and sulphonamides with essentially similar results. The combinations are bactericidal at therapeutic levels, the ratio of drugs to one another is not critical, and the effect is present over a fairly wid...
متن کاملDecreased binding of antibiotics to lipopolysaccharides from polymyxin-resistant strains of Escherichia coli and Salmonella typhimurium.
The interactions of polycationic antibiotics with lipopolysaccharide (LPS) isolated from parental and polymyxin-resistant strains of Salmonella typhimurium and Escherichia coli were measured by using a cationic spin probe. Electron spin resonance spectra indicated that increasing concentrations of cations competitively displaced probe from LPS aggregates. Polymyxin B and other cations displaced...
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ژورنال
عنوان ژورنال: Journal of Medicinal Chemistry
سال: 2009
ISSN: 0022-2623,1520-4804
DOI: 10.1021/jm900999h