Formation of 7-Cis Retinal by the Direct Irradiation of All-Trans Retinal1

Abstract
7-cis Retinal, one of the geometrical isomers of retinal [useful for studies of rhodopsin photochemistry], was prepared by the direct irradiation of all-trans retinal dissolved in ethanol and successive separation by high performance liquid chromatography. The procedures for its purification and identification were described.