Occurrence of 3-hydroxyretinol in the freshwater fish Bagarius bagarius and Wallago attu. Isolation and synthesis.

A new chromogen that absorbs maximally at 329 nm was frequently found in the liver oils of the freshwater fish Bagarius bagarius and Wallago attu. It was shown to be a diester of 3-hydroxyretinol. 3-Hydroxyretinol was found to be a metabolite of lutein during the biosynthesis of 3-dehydroretinol in a freshwater fish. A new method for the chemical synthesis of 3-hydroxyretinol from methyl 3-dehydroretinoate is described. The possible pathway for the conversion of lutein into 3-dehydroretinol in vivo is discussed.