Astaxanthin esters

A process for producing an aquatic animal feed supplement comprising an astaxanthin derivative of the general formula I

• selected from the group consisting of:
• astaxanthin-diethyldicarbonate (R is ethoxy),
• astaxanthin-diethyldioxalate (R is ethoxycarbonyl),
• astaxanthin-di(N-acetylglycinate) (R is acetylaminomethyl),
• astaxanthin-dimaleinate (R is —CH═CH—COOH),
• astaxanthin-disuccinate (R is —CH2—CH2—COOH),
• astaxanthin-dimethyldisuccinate (R is —CH2—CH2—COOCH3),
• astaxanthin-diethyldisuccinate (R is —CH2—CH2—COOC2H5),
• astaxanthin-diethyldiglycinedicarbamate (R is —NH—CH2—COOC2H5),
• astaxanthin-dinicotinate (R is 3-pyridyl),
• astaxanthin-dimethioninedicarbamate (R is —NHCH(CH2CH2SCH3)COOC2H5),
• astaxanthin-diacetyldiglycolate (R is acetyloxymethyl),
• astaxanthin-diphenylalaninedicarbamate (R is —NHCH(CH2C6H5)COOC2H5),
• astaxanthin-diethyldifumarate (R is —CH═CH—COOC2H5),
• astaxanthin-di(2-furoate) (R is 2-furyl),
• astaxanthin-dimethyldimalonate (R is —CH2—COOCH3),
• astaxanthin-di(3-methylthiopropionate) (R is 3-methylthioethyl),
• astaxanthin-dimethoxyacetate (R is methoxymethyl),
• astaxanthin-di-[(2-thienyl)acetate] (R is (2-thienyl)methyl),
• astaxanthin-dilactate (R is 1-hydroxyethyl),
• astaxanthin-di(acetylmandelate) (R is α-acetyloxybenzyl), and
• astaxanthin dibetainate (R is —CH2N+(CH3)3 Cl−);
• wherein the process comprises dissolving the astaxanthin derivative in a plant or vegetable oil or fat, or in an organic solvent, or in a mixture of both a plant or vegetable oil or fat and an organic solvent, emulsifying the solution with an aqueous solution of a protective colloid, at least partially removing the solvent and water to afford a concentrated emulsion, and spray-drying the concentrated emulsion to finally produce a formulation suitable for incorporation in a feed for aquatic animals.

A supplemented feed for aquatic animals comprising “an aquatic animal feed supplement comprising an astaxanthin derivative of the general formula I

• wherein
• R is in each case a group (a), (b) or (C)
• —NH—CH(R1)—COOR2 (a)
• —OR3 (b)
• —(Y)n—Z (c)
• R1 signifies hydrogen or the residue of a protein-forming amino acid,
• R2 signifies C1-6-alkyl or C3-8-cycloalkyl,
• R3 signifies C1-12-alkyl or C3-6-cycloalkyl,
• n signifies zero or 1,
• Y signifies C1-7-alkylene or C2-7-alkenylene,
• and Z when n is zero, signifies C3-8-cycloalkyl, a group —CH(C6H5)OR4, a group —COR5 or a group —CH2N−(CH3)3Hal−,
• or Z when n is 1, signifies amino, a group —O—COR6, a group —OR7 or a group —SR8,
• or Z regardless of whether n is zero or 1, signifies alternatively aryl, heteroaryl, a group —COOR5 or a group —CH(CH3)OR4,
• R4 signifies hydrogen or acetyl,
• R5 signifies hydrogen or C1-6-alkyl,
• R6 signifies C1-6-alkyl, aryl or heteroaryl,
• R7 signifies hydrogen, C1-8-alkyl or acetyl,
• R8 signifies C1-6-alkyl, and
• Hal− signifies a halogen ion,
• and a plant or vegetable oil or fat, an organic solvent, or a mixture of both a plant or vegetable oil or fat and an organic solvent;” in admixture with a feed for aquatic animals, wherein the astaxanthin derivative is selected from the group consisting of:
• astaxanthin-diethyldicarbonate (R is ethoxy),
• astaxanthin-diethyldioxalate (R is ethoxycarbonyl),
• astaxanthin-di(N-acetylglycinate) (R is acetylaminomethyl),
• astaxanthin-dimaleinate (R is —CH═CH—COOH),
• astaxanthin-disuccinate (R is —CH2—CH2—COOH),
• astaxanthin-dimethyldisuccinate (R is —CH2—CH2—COOCH3),
• astaxanthin-diethyldisuccinate (R is —CH2—CH2—COOC2H5),
• astaxanthin-diethyldiglycinedicarbamate (R is —NH—CH2—COOC2H5),
• astaxanthin-dinicotinate (R is 3-pyridyl),
• astaxanthin-dimethioninedicarbamate (R is —NHCH(CH2CH2SCH3)COOC2H5),
• astaxanthin-diacetyldiglycolate (R is acetyloxymethyl),
• astaxanthin-diphenylalaninedicarbamate (R is —NHCH(CH2C6H5)COOC2H5),
• astaxanthin-diethyldifumarate (R is —CH═CH—COOC2H5),
• astaxanthin-di(2-furoate) (R is 2-furyl),
• astaxanthin-dimethyldimalonate (R is —CH2—COOCH3),
• astaxanthin-di(3-methylthiopropionate) (R is 3-methyithioethyl),
• astaxanthin-dimethoxyacetate (R is methoxymethyl)
• astaxanthin-di-[(2-thienyl)acetate] (R is (2-thienyl)methyl),
• astaxanthin-dilactate (R is 1-hydroxyethyl),
• astaxanthin-di(acetylmandelate) (R is α-acetyloxybenzyl), and
• astaxanthin dibetainate (R is —CH2N+(CH3)3 Cl−).

A process for producing a feed for aquatic animals, which feed comprises an astaxanthin derivative of the general formula I

• selected from the group consisting of:
• astaxanthin-diethyldicarbonate (R is ethoxy),
• astaxanthin-diethyldioxalate (R is ethoxycarbonyl),
• astaxanthin-di(N-acetylglycinate) (R is acetylaminomethyl),
• astaxanthin-dimaleinate (R is —CH═CH—COOH),
• astaxanthin-disuccinate (R is —CH2—CH2—COOH),
• astaxanthin-dimethyldisuccinate (R is —CH2—CH2—COOCH3),
• astaxanthin-diethyldisuccinate (R is —CH2—CH2—COOC2H5),
• astaxanthin-diethyldiglycinedicarbamate (R is —NH—CH2—COOC2H5),
• astaxanthin-dinicotinate (R is 3-pyridyl),
• astaxanthin-dimethioninedicarbamate (R is —NHCH(CH2CH2SCH3)COOC2H5),
• astaxanthin-diacetyldiglycolate (R is acetyloxymethyl),
• astaxanthin-diphenylalaninedicarbamate (R is —NHCH(CH2C6H5)COOC2H5),
• astaxanthin-diethyldifumarate (R is —CH═CH—COOC2H5),
• astaxanthin-di(2-furoate) (R is 2-furyl),
• astaxanthin-dimethyldimalonate (R is —CH2—COOCH3),
• astaxanthin-di(3-methylthiopropionate) (R is 3-methylthioethyl),
• astaxanthin-dimethoxyacetate (R is methoxymethyl),
• astaxanthin-di-[(2-thienyl)acetate] (R is (2-thienyl)methyl),
• astaxanthin-dilactate (R is 1-hydroxyethyl),
• astaxanthin-di(acetylmandelate) (R is α-acetyloxybenzyl), and
• astaxanthin dibetainate (R is —CH2N+(CH3)3 Cl−);
• wherein the process comprises incorporating the astaxanthin derivative as a formulation in the feed by admixture of said formulation with at least some of the components of the final feed at an appropriate stage of its manufacture and subjecting the mixture containing the astaxanthin derivative to a hydrothermal process, thus producing the feed supplemented with the astaxanthin derivative.