Synonyms: 6-Methylheptanoyl-L-A2bu-L-Thr-L-A2bu-cyclo(L-A2bu*-L-A2bu-D-Phe-L-Leu-L-A2bu-L-A2bu-L-Thr-);Polymyxin B2;L-Threonine, N2-(6-methyl-1-oxoheptyl)-L-2,4-diaminobutanoyl-L-threonyl-L-2,4-diaminobutanoyl-L-2,4-diaminobutanoyl-L-2,4-diaminobutanoyl-D-phenylalanyl-L-leucyl-L-2,4-diaminobutanoyl-L-2,4-diaminobutanoyl-, cyclic (10-4)-peptide;Unii-99sjo09vh2