Cyclic polypeptide antibiotic from Bacillus colistinus. It is composed of Polymyxins E1 and E2 (or Colistins A, B, and C) which act as detergents on cell membranes. Colistin is less toxic than Polymyxin B, but otherwise similar; the methanesulfonate is used o…

Neomycin is a broad-spectrum aminoglycoside antibiotic drug that is derived from the metabolic products of _Streptomyces fradiae_.[L11979] Neomycin is a complex comprised of three components, neomycin A, B, and C.[A191529] Neomycin B, also known as [framyceti…

Polymyxin B was discovered in the 1940s[A176429]. They are basic polypeptides of about eight amino acids and have cationic detergent action on cell membranes[A176426]. Polymyxin B is used for infections with gram-negative organisms, but may be neurotoxic and …