Metabolism of carotenoids in salmonids. Part 2. Distribution and absolute configuration of idoxanthin in various organs and tissues of one atlantic salmon (Salmo salar, L.) fed with astaxanthin

✍ Scribed by Katharina Schiedt; Hans Mayer; Max Vecchi; Ernst Glinz; Trond Storebakken

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: German
• Weight: 322 KB
• Volume: 71
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19880710425

✦ Synopsis

The content of total carotenoids and the ratio astaxanthin/idoxanthin ( = 3,3'-dihydroxy-p,p-carotene-4,4'dione/3,3',4'-trihydroxy-fi,p-caroten-4-one) in various organs and tissues of one Atlantic salmon (Salmo salar, L.) reared indoors in a tank were analyzed after feeding 'racemic' ((3R,3'R)/(3R,3'S; meso)/(3S,3'S) 1 :2:1) astaxanthin (90 mg/kg feed) during one year. Configurational analysis of astaxanthin was carried out via the (-)-dicamphanate derivative and that of idoxanthin after reaction with (+)-(S)-I-(I-naphthy1)ethyl isocyanate. Separation of all eight optical isomers of idoxanthin-tricarbamate derivatives by HPLC is described. In salmon, enzymatic reduction of astaxanthin was found to be stereospecific leading to the (4'R)-hydroxy group irrespective of the configuration at C(3'), thus resulting in four different stereoisomers of idoxanthin formed from (3R,3'R), (3R,3'S; meso)-, and (3S,3'S)-astaxanthin present in the diet.