12 CELAXANTHIN 315 



12. CELAXANTHIN C4oH5gO* 



History and Occurrence 



In the course of investigations on the red berries of Celastrus scandens, A.L. 

 Le Rosen and Zechmeister^ found, besides /3-carotene, cryptoxanthin, zea- 

 xanthin, rubixanthin(?) and two unknown pigments present in very small 

 amounts, a new phytoxanthin, for which they proposed the name celaxanthin. 

 In its spectral properties the new pigment shows close similarity to rhodovio- 

 lascin (p. 297) and torulin (p. 329) so that these pigments are probably closely 

 related. 



Preparation^ 



The air-dried, bright red flesh of Celastrus berries (230 g) was extracted for a 

 short time with a mixture of petroleum ether and methanol (8:1.5) in a shaker. 

 It was then dried at 40°, finely ground, and again exhaustively extracted with the 

 same solvent mixture. The pigments obtained from the combined extracts were 

 dissolved in petroleum ether, the solution was washed free from methanol, dried 

 over sodiuin sulphate, and chromatographed on calcium hydroxide. The chromato- 

 gram was developed either with benzene or a mixture of benzene and acetone. -The 

 celaxanthin esters were found in the second zone from the top of the column, 

 beneath the zone of a phytoxanthin with absorption maxima at very long wave- 

 lengths (587, 547.5 m/x in carbon disulphide). The celaxanthin zone was arbitrarily 

 divided into two zones and the pigments were separately subjected to renewed 

 chromatography. They were then eluted with a mixture of benzene and methanol 

 (3:1), the solvent was evaporated and the pigments were precipitated with methanol 

 from a petroleum ether solution. The celaxanthin ester obtained in this manner was 

 saponified at room temperature with methanolic potassium hydroxide. The reaction 

 mixture was worked up in the usual way and the pigment obtained was purified by 

 adsorption on calcium hydroxide from a little benzene, and the column was washed 

 with a mixture of petroleum ether and acetone (10:1). After elution and removal 

 of the solvent by distillation, the celaxanthin was crystallised from a mixture of 

 ethanol'and carbon disulphide or benzene. 



The results of elementary analysis suggests a molecular formula C40H54O 

 or CjoHggO. The occurrence of a natural celaxanthin ester shows that the oxygen 

 is present in the form of a hydroxyl group. As the pigment does not show the 



* Or C^oHj.O. 

 References p. 341-343. 



