Occurrence and conversion of anhydrolutein into dehydroretinol in a freshwater fish.

1. Lutein and anhydrolutein have been isolated from liver oils of freshly caught Saccobranchus fossilis. 2. S. fossilis initially contained more dehydroretinol than retinol; administration of anhydrolutein to the vitamin A-depleted fish resulted in the accumulation of dehydroretinol. 3. Anhydrolutein has also been isolated from the liver oils of lutein-treated, vitamin A-depleted fish. 4. The pathway of the conversion of lutein into dehydroretinol is discussed.