85-1485-24　Colistin Sulfate (Mixture of A and B compound) 250mg　CAS No:1264-72-8　C7509

特徴

• Cyclic polypeptide antibiotic produced by Bacillus polymyxa. Complex mixture of at least 30 components, primarily colistin A and B.
• Colistin (polymyxin E) is a polymyxin antibiotic produced by certain strains of Bacillus polymyxa var. colistinus. Colistin is a mixture of cyclic polypeptides colistin A and B. Colistin is effective against most Gram-negative bacilli and is used as a polypeptide antibiotic. Colistin is a decades-old drug that fell out of favor due to its nephrotoxicity. It remains one of the last-resort antibiotics for multidrug-resistant Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter.[1] New Delhi metallo-β-Lactamase multidrug-resistant Enterobacteriaceae have also shown susceptibility to Colistin.[2]
• Colistin is polycationic and has both hydrophilic and lipophilic moieties. These poly-cationic regions interact with the bacterial outer membrane, by displacing bacterial counter ions in the lipopolysaccharide. Hydrophobic/hydrophillic regions interact with the cytoplasmic membrane just like a detergent, solubilizing the membrane in an aqueous environment. This effect is bactericidal even in an isosmolaric environment.
• Resistance to colistin is currently rare, but is described. At present there is no agreement about how to look for colistin resistance. The Société Française de Microbiologie uses a cut off of 2 mg/l, whereas the British Society for Antimicrobial Chemotherapy sets a cutoff of 4 mg/l or less as sensitive, and 8 mg/ml or more as resistant. There are not currently any US standards for measuring colistin sensitivity.
• Exceptional (inherently colistin resistant) Gram-negative bacteria:BrucellaBurkholderia cepaciaChryseobacterium indologenesEdwardsiellaElizabethkingia meningosepticaFrancisella tularensis spp
• Gram-negative cocciHelicobacter pyloriMoraxella catarrhalisNeisseria gonorrheae and Neisseria meningitidisProteusProvidenciaSerratiaSome strains of Stenotrophomonas maltophilia[18]
• Gram-negative organisms with variable resistance to colistin:AeromonasVibrioPrevotellaFusobacterium
• Synonyms:Polymyxin E. sulfate; Belcomycine; Colomycin
• Molecular Formula:x(C₅₃H₁₀₀N₁₆O₁₃)ₐ + x(C ₅₂H₉₈N₁₆O₁₃)B .xH₂
• Molecular Weight:1169.46
• Appearance:Supplied as an off-white solid.
• Purity:~98%
• Biological Potency (dry basis):19600U/mg
• Melting Point:>202°C (dec.)
• Specific Rotation (c=1, Water):-64.0 to -65º
• Colistin A:R= (+)-6-methyloctanoyl
• Colistin B:R= 6-methylheptanoyl
• Solubility:Water (Sparingly)
• Method for Determining Identity:Proton NMR (D2O)Spectroscopic and Mass Spectrometric Analysis
• TLC Conditions:C18; Water: Methanol: Acetic Acid; 7: 2: 1; Visualized with KMnO4; Single spot; Rf=0.35
• Elemental Analysis:Calculated: %C: 54.43, %H: 8.62, %N: 19.16
• Storage and Stability:May be stored at RT for short-term only. Long-term storage is recommended at -20°C. For maximum recovery of product, centrifuge the original vial prior to removing the cap.
• Important Note:This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological.
• Toxicity and Hazards:All products should be handled by qualified personnel only, trained in laboratory procedures.