The Biosynthesis of Astaxanthin-XIII: The Carotenoids in the Crab, Portunus Trituberculatus

The carotenoids of crab, Portunus trituberculatus, have been separated by absorption chromatography and further characterized by their absorption spectra and their behavior on the column. In some cases, reactions for specific functional groups were performed. The existence of canthaxanthin, 4-hydroxy-echinenone, 3-hydroxy-canthaxanthin and astaxanthin was confirmed in the carapaces of crab. In the internal organs, a-carotene echinenone, isocryptoxanthin and astaxanthin were found. The following metabolic pathway from a-carotene to astaxanthin was proposed. 8-carotene — ♦ isocryptoxanthin —-> echinenone —+ 4-hydroxy-echinenone —♦ canthaxanthin —+ 3-hydroxy-canthaxanthin —4 astaxanthin. © 1973, The Japanese Society of Fisheries Science. All rights reserved.