Claims
- 1. A method of preparing esterified astaxanthin from zeaxanthin comprising the steps of:
acylating zeaxanthin in an organic solvent with an acylating agent to produce esterified zeaxanthin; and contacting the esterified zeaxanthin with an oxidizing agent to produce esterified astaxanthin.
- 2. The method of claim 1, wherein the organic solvent is selected from the group consisting of chloroform and methylene chloride.
- 3. The method of claim 1, wherein the acylating agent is selected from the group consisting of RCOOH, RCOCl and (RCO)2,O, wherein R is a hydrocarbon chain of 2-20 hydrocarbons.
- 4. The method of claim 3, wherein R is a hydrocarbon chain of 2-8 hydrocarbons.
- 5. The method of claim 3, wherein R is a hydrocarbon chain of 2-4 hydrocarbons.
- 6. The method of claim 3, wherein the acylating agent is acetic anhydride.
- 7. The method of claim 1, wherein the oxidizing agent is produced by mixing a saturated aqueous solution selected from the group consisting of sodium sulfite, potassium sulfite, sodium hydrogen sulfite, potassium hydrogen sulfite, sodium bisulfite and potassium bisulfite, with a saturated solution of a bromate salt.
- 8. The method of claim 7, wherein the oxidizing agent is produced by mixing a saturated aqueous solution of sodium bisulfite with a saturated solution of sodium bromate.
- 9. The method of claim 8, wherein the ratio of sodium bisulfite to the sodium bromate is about 1.5:1.
- 10. The method of claim 7, wherein the oxidizing agent is produced by mixing a saturated aqueous solution of sodium bisulfite with a saturated solution of potassium bromate.
- 11. The method of claim 7, wherein the oxidizing agent is produced by mixing a saturated aqueous solution of sodium bisulfite with a saturated solution of calcium bromate.
- 12. The method of claim 7, wherein the oxidizing agent is produced by mixing a saturated aqueous solution of sodium bisulfite with a saturated solution of cerium bromate.
- 13. The method of claim 1, wherein the reaction temperature is between 0 to 25° C.
- 14. The method of claim 7, wherein the ratio of the oxidizing agent to the zeaxanthin esters is between 0.5 to 5 parts for each part of carotenoid.
- 15. The method of claim 7, wherein the pH of the aqueous oxidizing agent is between 1 to 4.
- 16. The method of claim 2, wherein the ratio of the organic solvent to the zeaxanthin esters is between 5 to 40 parts for each one.
- 17. The method of claim 1, wherein the zeaxanthin is obtained by saponification of a plant extract.
- 18. The method of claim 17, wherein the plant is marigold.
- 19. The method of claim 1, wherein the zeaxanthin is prepared synthetically.
- 20. The method of claim 1, further comprising the step of washing the esterified zeaxanthin with water before contacting the esterified zeaxanthin with the oxidizing agent.
- 21. An astaxanthin diester produced by the method of claim 1.
- 22. The astaxanthin diester of claim 21 which is an astaxanthin diacetate.
RELATED APPLICATIONS
[0001] This application claims priority to U.S. provisional application No. 60/421,623, filed Oct. 25, 2002, which is incorporated herein by reference in its entirety.
Provisional Applications (1)
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Number |
Date |
Country |
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60421623 |
Oct 2002 |
US |