Notes: Polymyxin E2 is a peptide antibiotic and a major constituent of the cationic lipopeptide antibiotic colistin (Item No. 17584) originally isolated from B. polymyxa.{40859} It is active against the plant pathogenic bacteria X. oryzae (EC50 = 0.21 µg/ml) and prevents and reverses rice bacterial leaf blight in greenhouse studies when applied at a concentration of 200 µg/ml.{72075}