all trans-Retinal

Химические свойства

Yellow Powder

Использование

Corotenoid component of the visual pigments. All-trans retinal is converted to retinoic acid in vivo by the action of retinal dehydrogenase.

Определение

ChEBI: A retinal in which all four exocyclic double bonds have E- (trans-) geometry.

Общее описание

All trans-Retinal is one of the major derivatives of vitamin A group. A variety of food serves as a source of vitamin A. It is predominant in liver and among the brightly colored vegetables.

Методы очистки

The aldehyde is separated from retinol by column chromatography on water-deactivated alumina. Elute with 1-2% acetone in hexane, or on TLC plates of silica gel G and using the same eluting solvent. It crystallises from pet ether or n-hexane as yellow-orange crystals, and the UV in hexane has max at 373nm (A1cm 1% 1,548) and 368nm ( 48,000). It is an irritant and is light sensitive. Store it in sealed ampoules under N2. The semicarbazone forms yellow crystals from CHCl3/Et2O or EtOH, m 199-201o(dec). The 9-cis-isomer [514-85-2] and the 13-cis-isomer [472-86-6] [max at 375nm ( 1,250) in EtOH] are also available commercially. [Beilstein 7 III 1742.]