Method for production of β-cryptoxanthin and α-cryptoxanthin from commercially available lutein
AssigneeUniversity of Maryland, College Park
InventorFrederick Khachik
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Abstract
The present invention relates to a method of reacting (3R,3′R,6′R)-lutein with a catalytic amount of an acid to obtain a mixture of anhydroluteins, rich in anhydrolutein III, with substantially no Z-isomers being formed. The mixture is converted to (3R)-β-cryptoxanthin (major product) and (3R,6′R)-α-cryptoxanthin (minor product) by reacting the anhydroluteins with borane-amine complexes (e.g. Me3N.BH3) or other hydride donors and an acid in a chlorinated solvent, preferably dichloromethane, at ambient temperature to produce (3R)-β-cryptoxanthin and (3R,6′R)-α-cryptoxanthin.
Claims36
A process for converting (a) (3R,3′R,6′R)-lutein (85% total carotenoids) or (b) purified lutein (97% total carotenoids) containing 5–7% (3R,3′R)-zeaxanthin or mixtures of (a) and (b) to a mixture of anhydroluteins I, II, and III at elevated temperature, comprising reacting (3R,3′R,6′R)-lutein in an alcohol or mixture of alcohols with a catalytic amount of an aqueous mineral acid or a strong organic acid at an elevated temperature of about 45° C. to about 100° C. to give a mixture of anhydroluteins comprising anhydrolutein III as the major product, anhydroluteins I and II as the minor products, and the recovered (3R,3′R)-zeaxanthin.
A process for converting (a) (3R,3′R,6′R)-lutein (85% total carotenoids) or (b) purified lutein (97% total carotenoids) containing 5–7% (3R,3′R)-zeaxanthin or mixtures of (a) and (b) to lutein 3′-alkyl ether, comprising reacting (3R,3′R,6′R)-lutein with an alcohol in the presence of a catalytic amount of an aqueous mineral acid or a strong organic acid at an elevated temperature to give all-E(trans)-lutein 3′-alkyl ether and the recovered (3R,3′R)-zeaxanithin.
A process for converting a mixture of all-E-anhydroluteins rich in all-E-anhydrolutein III, to a mixture of all-E-(3R)-β-cryptoxanthin and all-E-(3R,6′R)-α-cryptoxanthin, comprising reacting anhydroluteins containing 3–8% (3R,3′R)-zeaxanthin in a chlorinated solvent with about 1.3 equivalent of a hydride donor and about 3.5–4 equivalent of a strong organic acid at ambient temperature for about 1–5 hours to give a mixture of E/Z-(3R)-β-cryptoxanthin, E/Z-(3R,6′R)-α-cryptoxanthin, unreacted E/Z-anhydroluteins, and recovered E/Z-(3R,3′R)-zeaxanthin.
Dependencies are inferred from the claim text.