Discovery of cationic nonribosomal peptides as Gram-negative antibiotics through global genome mining

A pharmaceutical composition comprising a cationic nonribosomal peptide (CNRP) salt, wherein the CNRP comprises a hydrophobic N-terminal fatty acid chain, a linear cationic segment, and a hydrophobic tear peptide or pentapeptide ring, and the salt is:

• i) with an acid selected from hydrobromic acid, perchloric acid, nitric acid, thiocyanic acid, sulfuric acid, phosphoric acid, trifluoroacetic acid (TFA), cyclopentanepropionic acid, methanesulfonic acid, ethanesulfonic acid, 1,2-ethane-di sulfonic acid, 2-hydroxyethanesulfonic acid, benzenesulfonic acid, 4-chlorobenzenesulfonic acid, 2-naphthalenesulfonic acid, 4-toluenesulfonic acid, camphorsulfonic acid, 4-methylbicyclo[2.2.2]-oct-2-ene-1-carboxylic acid, 3-phenylpropionic acid, lauryl sulfuric acid, and hydroxynaphthoic acid;
• or
• ii) with a base selected from sodium hydroxide, ammonium hydroxide, potassium hydroxide, monoalkyl amine, dialkyl amine, trialkyl amine, and aryl amine.