CAROTENOIDS 



There is a differential distribution of carotenoids in Echinocardium 

 cordatum, for Goodwin and Srisukh^^^ found ^-carotene and echin- 

 enone to be the major components of the gonadal carotenoids, lutein 

 occurring only in traces ; in the peri-visceral fluid, however, there are 

 equal amounts of echinenone and lutein but no ^-carotene. Previously, 

 Lonnberg* had not obtained ** satisfactory " [sic] results with P. lividus 

 but had noted carotenoids in Psammechinus miliaris. Apart from a- and 

 P" carotenes, Lederer'* also isolated a second new carotenoid from 

 P. lividus, pentaxanthin (C4oH6flor ssOs), which appears to contain 

 3 hydroxyl groups and, although it has an absorption spectrum very 

 similar to that of lutein (xanthophyll) it is much more strongly 

 adsorbed on alumina than is lutein. {See also Table 26 and Fig. 23.) 



1-4 



1-2 



10 



0-8 



0-6 



0-4 



0-2 



380 400 420 440 460 480 500 520 



Wavelength (mn) 



Fig. 23. — The absorption spectra of Echinenone (from Goodwin, T. W., and Taha, 

 M. M. (1950) Biochem. J., 47, 244) and Pentaxanthin In CS, (fronr) Lederer, 

 £. {1938) Bull. Soc. Chim. Biol., 20, 61 1). 



Fox and Scheer'*' in their extensive study, to which reference has 

 previously been made, examined the carotenoid distribution in Dendraster 

 excentricuSf Strongly ocentrotus franciscanus, S. purpuratus, Lytechinus 



164 



