Ernst Glinz

Astaxanthin and its metabolites in wild rainbow trout (Salmo gairdneri R.)

Abstract 1. 1. The unusual intensely red exterior pigmentation of four wild rainbow trout, caught in an alpine lake of Austria, prompted quantitative and qualitative analysis of carotenoids in skin and flesh. 2. 2. Emphasis was laid on the absolute configuration of the hydroxycarotenoids. 3. 3. (3S,3′S- Astaxanthin was the main pigment in skin and flesh besides some yellow xanthophylls, which in skin were β-adonixanthin, (3R,3′S,6′R)- epilutein and (3R,3′R)- zeaxanthin and in flesh, lutein and zeaxanthin. 4. 4. The results are compared with data obtained in farmed rainbow trout fed unlabelled and tritiated astaxanthin enantiomers. 5. 5. The vitamin A1 (retinol) and A2 (dehydroretinol) statuses in liver were determined.

[15] Metabolism of carotenoids and in Vivo racemization of (3S,3′S)-Astaxanthin in the crustacean Penaeus

Publisher Summary In the shrimp Penaeus of the order Decapoda, as in most crustaceans, astaxanthin is the major carotenoid accumulated in the carapace. In the living animal, astaxanthin is bound noncovalently to a protein in a stoichiometric ratio. The carotenoprotein is water-soluble and may vary in color from blue to green to brown. This chapter discusses the in vivo racemization of optically active (3S,3′S )-[15,15′-3H2]astaxanthin in Penaeus japonicus. The fact that crustaxanthin and tetrahydroxypirardixanthin, the proposed reduction products of astaxanthin, were not labeled does not necessarily prove that these compounds are not involved in the metabolism of astaxanthin in Penaeus. Only one-fourth of the astaxanthin in the body was labeled and absorbed during the experimental period. The bulk of astaxanthin must have been biosynthesized or absorbed during the preexperimental period. Various systems of adsorption and reversed-phase chromatography on columns, thin layer chromatography, and high-performance liquid chromatography were used for the separation of the different carotenoids. The yellow carotenoids, such as isoastaxanthin and the tetrols, were acetylated immediately after saponification to improve their stability.

[26] Separation of the eight stereoisomers of all-rac-α-tocopherol from tissues and plasma: Chiral phase high-performance liquid chromatography and capillary gas chromatography

Publisher Summary This chapter introduces chiral phase high-performance liquid chromatography (HPLC) and capillary gas chromatography (GC). These methods are used to evaluate patterns of all α-tocopherol (TOH) stereoisomers in rat tissues and plasma after oral all -rac- α - TA c treatment. All separation steps are performed with α-T-ME derivatives—that is, only one α-TOH derivative is required. Chiralcel OD, a commercially available chiral high-performance liquid chromatography (HPLC) phase, is able to separate all four 2 R -α-T-ME stereoisomers individually from a peak containing the four 2S stereoisomers. The chiral phase HPLC method is developed with a Chiralpak OP(+) column, which separates all -rac- α - TA c into four peaks containing (all 2R), (SSS + SSR) , SRR , and SRS stereoisomers. Therefore, the system yields only limited information with regard to α-TOH stereoisomer distribution, whereas the combination of HPLC and GC methods permits the determination of all α-TOH stereoisomers individually. The GC–mass spectrometry (GC–MS) method is used to differentiate between R,R,R-α -TOH- d 6 and S,R,R-α- TOH- d 3 in rat tissues. It is not feasible to follow this experimental protocol for an evaluation of all -rac forms because it requires at least eight differently deuterated α-TAc stereoisomers and a very complex GC–MS setup to distinguish all individual stereoisomers.