Patent ID: 8877777

Claim:
A method of purifying the compound of Formula I or the salts thereof, wherein said method comprises: mixing a fermentation liquid comprising the compound of Formula I or the salts thereof with an organic solvent, and obtaining a first extract by filtration or centrifugation; diluting said first extract or concentrating said first extract under vacuum to reduce the content of the organic solvent and thereby obtain a second extract; loading said second extract onto a macroporous adsorption resin; washing the macroporous adsorption resin using water, an organic solvent, or a mixed solution of an organic solvent and water as a washing liquid; and eluting the compound of Formula I from the macroporous adsorption resin using water, an organic solvent, or a mixed solution of an organic solvent and water as eluent to provide a purified compound of Formula I or a salt thereof, wherein said organic solvent is selected from the group consisting of methanol, ethanol, propanol, butanol, acetone, and butanone.