Purification of glycopeptides
A novel and improved method for purification of glycopeptides, especially glycopeptide antibiotics. The method comprises contacting a solution of the glycopeptide to an ion exchange chromatography material. The product of this method has a surprisingly high purity.
1. A method for purification of a glycopeptide antibiotic using ion exchange chromatography, which comprises:
a) adjusting the salt concentration in a solution of the glycopeptide antibiotic to at least 0.2 M, and/or adjusting the conductivity of the solution of the glycopeptide antibiotic to at least 20 mS/cm;
b) contacting the solution of the glycopeptide antibiotic with an ion exchange material;
c) optionally washing the ion exchange material; and
d) removing the glycopeptide antibiotic from the ion exchange material, using an eluent.
2. The method of claim 1 , wherein the conductivity of the solution of the glycopeptide is adjusted to above 20 mS/cm.
3. The method of claim 1 , wherein the glycopeptide antibiotic is selected from the group consisting of a dalbaheptide, a group I vancomycin type glycopeptide; a group II avoparcin type glycopeptide; a group III ristocetin type glycopeptide; a group IV teicoplanin type glycopeptide; and a combination of one or more of the foregoing glycopeptide antibiotics.
4. The method of claim 1 , wherein the glycopeptide antibiotic is selected from the group consisting of Teicoplanin; and Vancomycin.
5. The method of claim 1 , wherein the ion exchange material is an anion exchange resin.
6. The method of claim 1 , wherein the conductivity of the solution of the glycopeptide is above 30 mS/cm.
7. The method of claim 1 , wherein the salt concentration during the ion exchange is higher than about 0.3 M.
8. The method of claim 1 , wherein the salt concentration during the ion exchange is lower than about 1.5 M.
9. The method of claim 1 , wherein an alkali metal salt is used for adjusting the salt concentration and/or the conductivity of the solution.
10. The method of claim 1 , in which the eluent is an acid or a solution of a salt.
11. The method of claim 1 , in which the eluent is an acid selected from the group consisting of a weak organic acid and a buffer comprising a weak organic acid and a corresponding base.
12. The method of claim 1 , wherein the glycopeptide antibiotic is teicoplainin A2, and the method further comprises adding an organic solvent to the teicoplainin factor A2 in an eluate from step d) to precipitate the teicoplainin factor A2.
13. The method of claim 12 , wherein the solution is colourless.
14. The method of claim 5 , wherein the anion exchange resin has a polymeric hydrophilic backbone.
15. The method of claim 9 , wherein the alkali metal salt is sodium, potassium or lithium salts of one of the following anions: Cl − , HSO 3 − , BrO 3 − , Br − , NO 3 − , ClO 3 − , HSO 4 − , HCO 3 − , IO 3 − , HPO 4 2− , formate, acetate, or propionate.
16. The method of claim 9 , wherein the alkali metal salt is NaCl.
17. The method of claim 11 , wherein the acid is acetic acid or citric acid.
18. The method of claim 11 , wherein the buffer is below pH 4.5 and wherein the concentration of the weak organic acid eluent acid is in the range from 0.1 M to 6.0 M.
19. The method of claim 11 , wherein the glycopeptide antibiotic is teicoplainin or vancomycin.