Liquid-gel partition chromatography of vitamin A compounds; formation of retinoic acid from retinyl acetate in vivo

Abstract

A clear separation of retinol, retinal, and retinoic acid has been achieved by liquid–gel partition chromatography on Sephadex LH-20 with solvent mixtures of chloroform, Skellysolve B, and methanol. A mixture of retinyl esters, retinol, retinal, and retinoic acid has been resolved on hydroxyalkoxypropyl Sephadex using Skellysolve B and acetone. There is no decomposition of any of the vitamin A compounds during chromatography, and recovery is complete. The combination of mildness and potential for resolution makes liquid–gel partition chromatography a superior tool for the separation of vitamin A compounds. This method has been applied to the study of vitamin A metabolism at physiological levels in the vitamin A-deficient rat. Retinyl palmitate, an ester of retinoic acid, retinal, retinol, retinoic acid, and a polar metabolite have been demonstrated in various tissues of the rat 12 hr after a dose of 2 μg of [11-14C]retinyl acetate.

Keywords

• retinol
• retinal
• retinyl esters
• Sephadex LH-20
• hydroxyalkoxypropyl Sephadex
• rat