Xanthophylls as precursors of retinoids
Xanthophylls such as canthaxanthin, astaxanthin, zeaxanthin, lutein and tunaxanthin that are widely distributed in Nature have been found to be precursors of retinoids not only in freshwater fish and marine fish (yellowtail) but also in mammals (rat). Reductive metabolic pathways from 3-dehydroretinol to retinol and from 3-dehydroretinal to retinal have been newly discovered by feeding experiments with rat and yellowtail, respectively.