Figure 1
From: LC-MS/MS determination of colistin in Mueller–Hinton broth for in vitro pharmacodynamic studies
Chemical structure of colistin A and colistin B. Dab=L-α, γ-diaminobutyric acid. α and γ indicate the respective -NH2 involved in the peptide linkage. Polymyxin E1 (colistin A): FA=(+)-6-methyloctanoate, X=D-Leu; polymyxin E2 (colistin B): FA=(+)-6-methylheptanoate, X=D-Leu; polymyxin B1: FA=(+)-6-methyloctanoate, X=Phe.
