CAROTENOIDS 



cryptoxanthin palmitate. There is more cryptoxanthin than [3-carotene 

 in the rind of Seville oranges^' ^'^'^ and it constitutes about 30 per cent, 

 of the total carotenoid of the pulp of Indian oranges, but is slightly less 

 abundant (25 per cent.) in the rind. ^ * ' 



Physalien, ^ ' * the pigment responsible for the deep red colour of 

 mature berries of P. alkekengi is zeaxanthin dipalmitate^® ; there is no 

 zeaxanthin in the unripe sepals. ^ ' * Zeaxanthin is apparently the 

 principal carotenoid in fruit of the palm Cycas revoluta ^ ' ^ and it also 

 occurs in kaki fruit (Diospyros kaki). ^ ' ^ Violaxanthin and flavoxanthin 

 have been reported in Cotoneaster occidentalis and Pryacantha coccinea " * 

 berries, respectively. 



Xanthophylls having considerable species specificity have been 

 isolated from fruits of yt\v (Taxus baccata), rhodoxanthin, ^ ' ' rose hips, 

 (Rosa rubiginosa) rubixanthin, ^ '' ^ v^oody nightshade (Solanum dulca- 

 mara) lycoxanthin and lycophyll ;^''^ red peppers (Capsicum annuum)^ 

 capsorubin and capsanthin ; ^ ® ° false bittersw^eet (Celastrus scandens), 

 celaxanthin, ^ * ^ oranges citroxanthin ; ^ ^ ^ and from spindle tree berries 

 (Euonymus europaeus) antheraxanthin ^ ^ ^ {see p. 50). Citroxanthin has 

 recently been identified as mutatochrome ^ ^ * {see p. 15). 



Me 



■Me 



Me 



Rhodoxanthin (3 : 3'-diketodehydro-p-carotene) 



Me Me M« 



Rubixanthin (CigHseO) (3-hydroxy - y-carotene) 



HO 



Me 



Me Me Me 



Me- 



Me 



Me Me Me 



Lycoxanthin (C^oHjeO- 3-hydroxylycopene' 



32 



