Isolation of bacitracins A and F by high-speed counter-current chromatography.

The major components of bacitracin were separated and purified using high-speed counter-current chromatography (HSCCC). A systematic search for optimum two-phase solvent systems resulted in two systems: chloroform-ethanol-methanol-water (5:3:3:4) and chloroform-ethanol-water (5:4:3). These were selected based on the determination of the partition coefficients of all the components and the settling time of the phases. HSCCC with these solvent systems separated two components, bacitracins A and F. Improvements in the flow-cell arrangement eliminated noise in detection, making in-line monitoring possible. A tandem mass spectrometric technique was used to characterize the isolated components.