ANIMAL CAROTENOIDS 



Me Me Me 



Me M<? Mo 



Me 



Astacin 



I 4r 



1-2 



10 



0-6 



OA 



0-2 







420 440 



460 480 500 520 



Wavelength (mfi) 



540 



560 



Fig. 24. — The absorption spectra of Astaxanthin and Asucin {from Goodwin^ 

 T. W., and Shsukh, S. {1949) Biochem, J., 45, 263). 



Kuhn and Lederer found that the pigment from the eggs behaved 

 differently from that of the hypodermis and carapace (blue spots). The 

 former was hypophasic to 90 per cent, methanol and the latter epiphasic. 

 They both gave astacin on saponification. It was assumed that the pig- 

 ments were two distinct esters of astacin, the first being named 

 " ovoester." 



However, in 1938, Kuhn and Sorensen*^ showed that astacin was 

 an oxidative artefact of astaxanthin^ the naturally occurring pigment. 

 Conditions such as alkaline saponification readily bring about the 

 change. Astaxanthin is 3, 3'-dihydroxy-4 : 4'-diketo-(3-carotene and 

 is identical with Kuhn and Lederer's ovoester, the hypodermal ester 



169 



