title: Metabolism of three stereoisomers of astaxanthin in the fish, rainbow trout and tilapia.
abstract: In rainbow trout (Salmo gairdneri), the dietary astaxanthin diesters were mostly absorbed and accumulated in their integuments keeping their configurations, and partially metabolized to (3R, 3'R)-zeaxanthin (major) and/or (3R, 3'S)-zeaxanthin (medium) and/or (3S,3'S)-zeaxanthin (minor). In tilapia (Tilapia nilotica), the three stereoisomers of astaxanthin diesters were promptly metabolized to only (3S,3'S)-astaxanthin, and subsequently to (3R,3'R)-zeaxanthin and/or (3R,3'S)-zeaxanthin and/or (3S,3'S)-zeaxanthin at an invariable ratio, 4:1:0.3. The above facts indicate that the conversion from 3S- to 3R-configuration was carried out in vivo, and vice versa, and that astaxanthins were reductively metabolized to zeaxanthins in both the fish.
mesh_terms: D000818:Animals; D002338:Carotenoids / Q000031:analogs & derivatives / Q000378:metabolism*; D005399:Fishes / Q000378:metabolism*; D012487:Salmonidae / Q000378:metabolism*; D013045:Species Specificity; D013237:Stereoisomerism; D014337:Trout / Q000378:metabolism*; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene / Q000031:analogs & derivatives*
chemical_list: D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene; D002338:Carotenoids; C005948:astaxanthine