Polymyxin

Polymyxins are cationic detergent antibiotics, with a general structure of a cyclic peptide with a long hydrophobic tail. They disrupt the structure of the bacterial cell membrane by interacting with its phospholipids. Polymyxins have a bactericidal effect on Gram-negative bacilli, especially on Pseudomonas and coliform organisms. Polymyxin antibiotics are highly neurotoxic and nephrotoxic, and very poorly absorbed from the gastrointestinal tract. Polymyxins also have antifungal activity.

Well known examples:


 * Colistin
 * Polymyxin B
 * Surfactin

Polymyxin acts as an antibiotic by damaging the cytoplasmic membrane of bacteria. Also polymyxins biological source is Bacillius polymyxa.