Claims
- 1. A method for preparing astaxanthin from zeaxanthin or 3,3′,4,4′-tetrahydroxy-β-carotene, comprising contacting said zeaxanthin or 3,3′,4,4′-tetrahydroxy-β-carotene with a halogenating agent in the presence of chloric or bromic acid or salts thereof.
- 2. The method of claim 1, wherein said halogenating agent is selected from the group consisting of N-bromosuccinimide, bromine, pyridinium tribromide, iodine, and mixtures thereof either added directly or generated in situ with a compound selected from the group consisting of sodium bromide, potassium bromide, sodium iodide and potassium iodide.
- 3. The method of claim 2 further comprising a reaction solvent system, wherein said reaction solvent is selected from the group consisting of an organic solvent and water.
- 4. The method of claim 3, wherein said organic solvent is chloroform.
- 5. The method of claim 4, wherein said halogenating agent is N-bromosuccinimide or pyridinium tribromide.
- 6. The method of claim 4, wherein said halogenating agent is generated in situ from a mixture of an oxidizing agent and a compound selected from the group consisting of potassium bromide, sodium bromide, sodium iodide and potassium iodide.
- 7. The method of claim 6, wherein said oxidizing agent is selected from the group consisting of bromic acid, chloric acid and salts thereof.
- 8. The method of claim 6, wherein the mixture is acidic.
- 9. The method of claim 8, wherein the mixture comprises a solution of sodium bromate and potassium bromide.
- 10. The method of claim 8, wherein the mixture comprises a solution of sodium iodine and sodium chlorate.
- 11. A method for preparing 3,3′,4,4′-tetrahydroxy-β-carotene from zeaxanthin, comprising contacting said zeaxanthin with a halogenating agent to form a mixture followed by contacting said mixture with a base.
- 12. The method of claim 11, wherein said halogenating agent is N-bromosuccinimide and said base is an amine base.
- 13. The method of claim 11, wherein said halogenating agent is selected from the group consisting of N-bromosuccinimide, bromine, pyridinium tribromide, iodine, and mixtures thereof either added directly or generated in situ with a compound selected from the group consisting of sodium bromide, potassium bromide, sodium iodide and potassium iodide.
- 14. The method of claim 11 further comprising a reaction solvent system, wherein said reaction solvent is selected from the group consisting of an organic solvent and water.
- 15. The method of claim 14, wherein said organic solvent is chloroform.
- 16. The method of claim 14, wherein said halogenating agent is N-bromosuccinimide and said amine base is N,N-diisopropylethylamine.
- 17. A method for preparing astaxanthin from 3,3′,4,4′-tetrahydroxy-β-carotene, comprising contacting said 3,3′,4,4′-tetrahydroxy-β-carotene with a mixture comprising a halogenating agent and an acid selected from the group consisting of bromic acid, chloric acid and salts thereof.
- 18. The method of claim 17 further comprising a reaction solvent system, wherein said reaction solvent is selected from the group consisting of an organic solvent and water.
- 19. The method of claim 18, wherein said organic solvent is chloroform.
- 20. The method of claim 17, wherein said halogenating agent is generated in situ from a mixture of an oxidizing agent and a compound selected from the group consisting of potassium bromide, sodium bromide, sodium iodide and potassium iodide.
- 21. The method of claim 20, wherein the oxidizing agent is selected from the group consisting of bromic acid, chloric acid, and salts thereof.
- 22. The method of claim 20, wherein the mixture is acidic.
- 23. The method of claim 22, wherein the mixture comprises solutions of sodium bromate and potassium bromide.
- 24. The method of claim 22, wherein the mixture comprises solutions of sodium iodine and sodium chlorate.
- 25. The method of claim 17, wherein the halogenating agent is N-bromosuccinimide.
Parent Case Info
This application claims the benefit of provisional application 60/199,875 filed Apr. 26, 2000.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
4212827 |
Paust et al. |
Jul 1980 |
A |
5625099 |
Ernst et al. |
Apr 1997 |
A |
Provisional Applications (1)
|
Number |
Date |
Country |
|
60/199875 |
Apr 2000 |
US |