CAROTENOIDS 



Karrer and Rutschman » «• ' • isolated the acidic material and named 

 it torularhodin (C37H48O2). It contains one carboxyl group and thus 

 does not owe its acidic character to keto enol tautomerism. Further 

 investigations showed that torularhodin had vitamin A activity and 

 the following structure is suggested : * • 



COOH 



Me 



Torularhodin 



400 



420 440 



460 480 500 



Wavelength (mfi) 



520 540 



Fig. 17. — TJie absorption spectra of 



(o) Torulene in hexane 



(b) The acidic carotenoid present in Neurospora crassa, in light 



petroleum. 



(0) redrawn from Lederer, E. (1938) Bull Soc. Chim. Biol., 20, 554. 

 (b) redrawn from Haxo, F. (1949) Arch. Biochem, 20, 400. 



Torularhodin was the main pigment present in Karrer's cultures 

 and also the main component of the carotenoids extracted from R. 

 sanniei by Fromageot and Tschang, *o who detected y-carotene and 



106 



