CAROTENOIDS IN LAND PLANTS 



bonds with the os-configuration. Protetrahydrolycopene (previously 

 named all-m-lycopene, ^ " poly-a>- ^j;-carotene ^ « « and unidentified 

 1 1 * «) is also a poly-os- compound. 



In addition to prolycopene Zechmeister and Pinckard^'* isolated 

 6 further lycopene isomers from P. angustifolia berries and named 

 them poly «j-lycopenes I- VI, according to their adsorptive power, the 

 first member being the most strongly adsorbed. The absorption 

 spectra of these isomers are recorded in Fig. 10. 

 14 



12 



10 



11 



360 



380 400 



420 440 460 

 Wavelength (mfij 



480 



500 



Fig. 10. — The absorption spectrum in hexane of Prolycopenes I — VI. {From 

 Zechmeister, L, and Pinckard,]. H. {1947) J. Amer. Chem. Soc, 69, ]930.) 



n. Xanthophylls 



Turning to fruit xanthophylls, they differ from leaf xanthophylls in 

 three main features, (a) they are generally esterified, (b) there is a 

 different quantitative distribution, and (c) many fruit contain xantho- 

 phylls peculiar to themselves. 



Cryptoxanthin,^'^ although only present in leaves in traces, con- 

 stitutes one-third of the total carotenoids of the berries of Physalis 

 alkekengi L. (P. franchetti Hort.) from which it was first isolated ; 

 Karrer and Schlientz^"' consider that the pigment isolated from 

 Carica papaya and Citrus poonensis and termed caricaxanthin^'' ^ is 



31 



