Patent ID: 7138487

Claim:
A method for purifying a lipopeptide antibiotic, said method comprising the steps of: contacting an aqueous solution comprising a lipopeptide antibiotic, a divalent cation, and a pH above the isoelectric point of the lipopeptide antibiotic with an organic solvent, thereby extracting the lipopeptide antibiotic into the organic solvent, wherein the lipopeptide antibiotic is a derivative of any of the following lipopeptide antibiotics: zaomycin, crystallomycin, amphomycin, aspartocin, glumamycin, daptomycin, antibiotic A1437, antibiotic A-21978C, antibiotic A-54145 or tsushimycin, wherein the derivative is not laspartomycin; and contacting the organic solvent extract of the lipopeptide antibiotic with acid.