II CHRYS ANTHEM AX ANTHIN 211 



II. CHRYSANTHEMAXANTHIN C4oH5g03 



History 



1943 Karrer and Jucker isolate chrysanthemaxanthin from red and yellow 

 blossoms of asters^*^. 



1944 The new phytoxanthin is found in blossoms of Sarothamnus scoparius and 

 investigated in more detaiP**. 



1945 Karrer and Jucker prepare chrysanthemaxanthin by a partial syn- 

 thesis and thus establish its constitution^*^. 



Occurrence 



Up to the present time, chrysanthemaxanthin has not been frequently 

 found in nature. It is always accompanied by xanthophyll and usually by 

 fiavoxanthin. This fact allows certain conclusions to be drawn concerning its 

 mode of formation in the plant (cf. the original communication by Karrer 

 and JuckerI*^). 



TABLE 46 



OCCURRENCE OF CHRYSANTHEMAXANTHIN IN BLOSSOMS 



Asters P. Karrer and E. Jucker, T/e/t'. c/u'm. ^cto 26 (1943) 626. 



Gorse P. Karrer and E. Jucker, Helv. chim. Acta 2y (1944) 



1585. 

 Ranunculus acer P. Karrer, E. Jucker, J. Rutschm.\nn and K. Stein- 



LiN, Helv. chim. Acta 28 (1945) 1146. 



Preparation 



The extraction of the pigment meets with some difficulty. The supply of 

 large quantities of asters is costly, and the yield of chrysanthemaxanthin is 

 small^*®. Larger quantities of this phytoxanthin can be obtained from gorse 

 blossoms, but the picking of the blossoms must be done very carefully and their 

 content of chrysanthemaxanthin depends on the season^*'. It is therefore 

 preferable to prepare chrysanthemaxanthin synthetically from xanthophylP*^. 



For this purpose xanthophyll is converted into xanthophvU epoxide by the 

 action of a dilute ethereal solution of monoperphthalic acid. By treatment with 

 dilute hydrochloric acid, the epoxide is converted into a mixture of fiavoxanthin, 

 chrysanthemaxanthin and a little xanthophyll. The separation and purification of 

 the pigments can be achieved by adsorption on zinc carbonate from benzene solu- 

 tion, followed by crystallisation of the phytoxanthins from a mixture of benzene 

 and methanol. 



References p. 214-212. 



