Abstract: The invention relates to a process for the purification of riboflavin comprising the steps of (a) precipitating a first crystalline form of riboflavin, (b) isolating the first crystalline form of riboflavin, (c) transforming the first crystalline form of riboflavin into a second crystalline form of riboflavin under conditions that decompose diluted DNA, and (d) isolating the second crystalline form of riboflavin, provided that at ambient temperature the first crystalline form of riboflavin is thermodynamically less stable than the second crystalline form of riboflavin.

Abstract: Salts of Astaxanthin derivatives of the general formula I for use as fish feed additive, wherein R is in each case a group —NH—CH(R1)—COOR2, —OR3 or —(Y)n-Z and R1, R2, R3, Y, Z and n are significances given in detail in the description, are novel compounds with improved stability during extrusion at the elevated temperatures as required in feed manufacture and during the storage of the manufactured feed and which accordingly are useful as pigmenting carotinoids for feed for aquatic animals. The derivatives are produced by reacting astaxanthin with the pertinent acid RCOOH as such or as its acid chloride RCOCl or acid anhydride (RCO)2O, or, in the cases where R signifies a group —NH—CH(R1)—COOR2, with the appropriate N-carbonyl-amino acid ester of the formula OCNCH(R1)COOR2.

Abstract: Astaxanthin derivatives of the general formula (I) wherein R is in each case group —NH—CH(R1)—COOR2, —OR3 or —(Y)n-Z and R1, R2, R3, Y, Z and n are significances given in detail in the description, are novel compounds with improved stability during extrusion at the elevated temperatures as required in feed manufacture and during the storage of the manufactured feed and which accordingly are useful as pigmenting carotinoids for feed for aquatic animals. The derivatives are produced by reacting astaxanthin with the pertinent acid RCOOH as such or as its acid chloride RCOC1 or acid anhydride (RCO)2O, or, in the cases where R signifies a group —NH—CH(R1)—COOR2, with the appropriate N-carbonyl-amino acid ester of the formula OCNCH(R1)COOR2.

Abstract: Astaxanthin derivatives of the general formula I wherein R is in each case a group —NH—CH(R1)—COOR2, —OR3 or —(Y)n—Z and R1, R2, R3, Y, Z and n are significances given in detail in the description, are novel compounds with improved stability during extrusion at the elevated temperatures as required in feed manufacture and during the storage of the manufactured feed and which accordingly are useful as pigmenting carotinoids for feed for aquatic animals. The derivatives are produced by reacting astaxanthin with the pertinent acid RCOOH as such or as its acid chloride RCOCl or acid anhydride (RCO)2O, or, in the cases where R signifies a group —NH—CH(R1)—COOR2, with the appropriate N-carbonyl-amino acid ester of the formula OCNCH(R1)COOR2. In particular, astaxanthin disuccinate and astaxanthin dimethyldisuccinate are disclosed.

Abstract: The invention relates to a process for the purification of riboflavin comprising the steps of (a) precipitating a first crystalline form of riboflavin, (b) isolating the first crystalline form of riboflavin, (c) transforming the first crystalline form of riboflavin into a second crystalline form of riboflavin under conditions that decompose diluted DNA, and (d) isolating the second crystalline form of riboflavin, provided that at ambient temperature the first crystalline form of riboflavin is thermodynamically less stable than the second crystalline form of riboflavin.

Abstract: Astaxanthin derivatives of the general formula (I) wherein R is in each case group —NH—CH(R1)—COOR2, —OR3 or —(Y)n-Z and R1, R2, R3, Y, Z and n are significances given in detail in the description, are novel compounds with improved stability during extrusion at the elevated temperatures as required in feed manufacture and during the storage of the manufactured feed and which accordingly are useful as pigmenting carotinoids for feed for aquatic animals. The derivatives are produced by reacting astaxanthin with the pertinent acid RCOOH as such or as its acid chloride RCOCl or acid anhydride (RCO)2O, or, in the cases where R signifies a group —NH—CH(R1)—COOR2, with the appropriate N-carbonyl-amino acid ester of the formula OCNCH(R1)COOR2.

Abstract: A process for catalytically isomerizing Z-3-methylpent-2-en-4-yn-1-ol to E-3-methylpent-2-en-4-yn-1-ol is provided. This process includes contacting a stereoisomeric mixture containing Z-3-methylpent-2-en-4-yn-1-ol and E-3-methylpent-2-en-4-yn-1-ol with a source of bromine radicals in a two-phase reaction mixture having an aqueous phase and a stereoisomeric mixture phase, intermixing the reaction mixture, and heating the reaction mixture to a temperature from about −10° C. to about 100° C.

Abstract: A process for catalytically isomerizing Z-3-methylpent-2-en-4-yn-1-ol to E-3-methylpent-2-en-4-yn-1-ol is provided. This process includes contacting a stereoisomeric mixture containing Z-3-methylpent-2-en-4-yn-1-ol and E-3-methylpent-2-en-4-yn-1-ol with a source of bromine radicals in a two-phase reaction mixture having an aqueous phase and a stereoisomeric mixture phase, intermixing the reaction mixture, and heating the reaction mixture to a temperature from about −10° C. to about 100° C.