Process for the production of (−)-epigallocatechin gallate
View Patent ↗A process is provided for making (−)-epigallocatechin gallate (EGCG) by subjecting a green tea extract to chromatography on a macroporous polar resin, eluting EGCG from the resin with a polar elution solvent, optionally concentrating the eluate, optionally regenerating the resin by desorbing the remaining catechins, and optionally concentrating the desorbed catechins.
1. A process for producing (−)-epigallocatechin gallate (EGCG) comprising the steps of:
a) providing a green tea extract containing tea catechins and caffeine;
b) subjecting the green tea extract to chromatography on a macroporous polar resin at a temperature between about 40° C. to about 60° C.; and
c) eluting the EGCG from the macroporous polar resin with a polar elution solvent at a temperature between about 40° C. to about 60° C. and at a pressure between about 0.1 bar to about 50 bar.
2. A process according to claim 1 further comprising concentrating the eluate of step c).
3. A process according to claim 1 further comprising regenerating the macroporous polar resin by desorbing any remaining catechins from the resin.
4. A process according to claim 3 further comprising concentrating the desorbed catechins.
5. A process according to claim 1 wherein the macroporous paler resin is selected from the group consisting of polyacrylate resins, polymethacrylate resins, polyamide resins, and polyester resins.
6. A process according to claim 5 wherein the macroporous polar resin is a polyacrylate or polymethacrylate resin.
7. A process according to claim 5 wherein the polyamide resin is Polyamide 11.
8. A process according to claim 1 wherein steps b) and c) are carried out at a temperature between about 20° C. to about 60° C.
9. A process according to claim 8 wherein the temperature is between about 40° C. to about 60° C.
10. A process according to claim 1 wherein step c) is carried out under a pressure of about 0.1 bar to about 20 bar.
11. A process according to claim 10 wherein the pressure is about 0.1 bar to about 10 bar.
12. A process according to claim 1 wherein the polar elution solvent is a mixture of water and an organic solvent.
13. A process according to claim 12 wherein the elution solvent is a mixture of about 70 vol % to about 95 vol % of water and about 5 vol % to about 30 vol % of an organic solvent.
14. A process according to claim 13 wherein the elution solvent is a mixture of about 90 vol % of water and about 10 vol % at an organic solvent.
15. A process according to claim 12 wherein the organic solvent is selected from the group consisting of ethanol, isopropanol, ethyl acetate, and acetone.
16. A process according to claim 1 wherein the elution of step c) is carried out at a flow rate in the range of about 0.5 to about 20 bed volumes/hour.
17. A process according to claim 16 wherein the elution is carried out at a flow rate in the range of about 0.5 to about 10 bed volumes/hour.
18. A process according to claim 17 wherein the elution is carried out at a flow rate in the range of about 0.8 to about 5 bed volumes/hour.
19. A process according to claim 1 further comprising concentrating an eluate from step a) by adding to the eluent an acid selected from the group consisting of citric acid, ascorbic acid, and isoascorbic acid.
20. A process according to claim 19 wherein the amount of acid added to the eluent is about 0.1 wt % to about 2.5 wt % with respect to EGCG.
21. A process according to claim 2 wherein the concentrating step is carried out with a pure organic solvent.
22. A process according to claim 21 wherein the organic solvent consists of essentially about 10 vol % to about 60 vol % of water and about 40 vol % to about 90 vol % of an organic solvent.
23. A process according to claim 22 wherein the solvent consists of essentially of a mixture of about 40 vol % of water and about 60 vol % of an organic solvent.