PROrERTIES OF THE CAROTENOIDS 



019 



Table 18 ' 

 MoLEcuL.^R Extinction Coefficients of Some C.\rotenoids as Measured i.v 

 Beckman Spectrophotometer 



" L. Zechmeister, Chern. Revs., 34, 267-344 (1944). 



'' Personal communication from Professor L. Zechmeister. 



• L. Zechmeister and R. M. Lemmon, J. Am. Chem. Soc, 66, 317-322 (1944). 



<* A. Chatterjee and L. Zechmeister, /. Am. Chem. Soc, 72, 254-256 (1950). 



« A. Polgar and L. Zechmeister, /. Am. Chem. Soc, 66, 186-190 (1944). 



carotenoids are distributed between a mixture of diethyl ether and petro- 

 leum ether on the one hand, and 85% methyl alcohol on the other hand, 

 one finds that a-, /3-, and 7-carotene, lycopene, and esters of the carotenols 

 (such as the colored fats) are present almost exclusively in the upper ether 

 layer. They are referred to as being epiphasic. The carotenols, such as 

 lutein (xanthophyll), zeaxanthin, violaxanthin, taraxanthin, fucoxanthin, 

 and unesterified capsanthin, are to be found practically quantitatively in 

 the aqueous methanol layer on the bottom (hypophasic) . Although the 

 monohydrox}' carotenoids may be epiphasic with respect to 85% methanol, 

 they are hypophasic, or largely so, with respect to 95% methyl alcohol. 

 One can effect a further separation by saponification of the carotene frac- 

 tion, after which the carotenols set free by hydrolysis of the colored fats 

 can be extracted from the carotene with 85% methanol. 



