Hoffmann-la Roche Inc.

Roche Vitamins Inc.

Kurt Bernhard

Paul Kreienbuhl

Urs O Hengartner

Jiri Broz

Katharina Schiedt

Bruno H Leuenberger

Ulrich Schwieter

Robert K Muller

Alfred Giger

Robert Spruijtenburg

Stephan Jaggli

Markus Ivo Beck

A process for the conversion of lutein or of its esters into zeaxanthin by base-catalyzed isomerization is disclosed. The process is carried out by heating an optionally pre-treated lutein-containing material in a mixture of an aqueous solution of an alkali hydroxide and either dimethyl sulphoxide or an organic solvent based on saturated aliphatic and/or aromatic hydrocarbons at temperatures in the range from about 50.degree. C. to about 120.degree. C. The process is carried out in the presence of a phase transfer catalyst when an organic solvent based on hydrocarbons is used. Being carotenoids, lutein and zeaxanthin are used correspondingly, especially as pigments for egg yolk, the integuments and the subcutaneous fat of poultry, the flesh and the integuments of fish and crustaceans, as well as foodstuffs. Zeaxanthin is preferably used in many applications, since in comparable dosages it produces a more intensive golden yellow pigmentation than lutein.

Process for the manufacturing of zeaxanthin from lutein

A method of pigmenting certain parts and products of poultry, fish and crustacea by including in the feed of the pertinent animal one or more of the carotenoids 2'-dehydroplectaniaxanthin, desmethylspheroidenone, spheroidenone, 1-hydroxy-3,4-didehydro-1,2-dihydro-.psi.,.psi.-caroten-2-one, 5'-hydroxy-5',6'-dihydro-4'-apo-.beta.-caroten-6'-one, 1'-hydroxy-3',4'-didehydro-1',2'-dihydro-.beta.,.psi.-carotene-4,2'-dione and 5'-hydroxy-5',6'-dihydro-4'-apo-.beta.-carotene-4,6'-dione, poultry, fish and crustacea feeds for pigmenting certains parts and products of these animals, beadlets and premixes for adding to poultry, fish and crustacea feeds, and the carotenoids 1-hydroxy-3,4-didehydro-1,2-dihydro-.psi.,.psi.-caroten-2-one, 5'-hydroxy-5',6'-dihydro-4'-apo-.beta.-caroten-6'-one, 1'-hydroxy-3',4'-didehydro-1',2'-dihydro-.beta.,.psi.-carotene-4,2'-dione and 5'-hydroxy-5',6'-dihydro-4'-apo-.beta.-carotene-4,6'-dione.

Pigmentation with carotenoids

A process for producing carotenoids and carotenoid intermediates via reduction of sulfonyl polyenes with a dithionite in the presence of ammonia or an aliphatic amine, including novel intermediates in this process, which carotenoids are known coloring agents for foodstuffs, animal feeds, pharmaceuticals, etc.

Sulfone polyene intermediates

A silyl-enol ether of the formula ##STR1## wherein n stands for the number and X stands for a group ##STR2## or n stands for the number 1 and X stands for the 6,11-dimethylhexadeca-2,4,6,8,10,12,14-heptaene-2,15-diyl group, the symbols R.sup.1 have the same or different significances and denote alkyl groups, and the symbol R.sup.2 represents a trialkylsiloxy group --OSi(R.sup.1).sub.3 or an ether group, is oxidized with percarboxylic acid and, if desired, the resulting .alpha.-siloxy ketone is hydrolyzed to an .alpha.-hydroxy ketone. This process is especially suitable for the manufacture of astaxanthin.

Cyclohexenone derivatives and process for making same

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Lupsingen, Switzerland

Kurt Bernhard