CONSTITUENTS OF THE BIOSPHERE 37 



CH, CH, 



\ / 



C OH CH3 CH, CHi 



/ \ / \ I I 



CHj CCH=CHC=zCHCH = CHC=CHCH = CHCH=C CHzrCHCOOH 



I I 



CHa CCH, 

 \ / \ Azafrine 



CHa OH 



CH, CH, 

 \ / 



C CH, CH, CH, CH, 



/ \ I I I I 



CH, CCH=CHC=CHCH=CHC=CHCHr=CHCH = CCH=CHCH = CCHO 



I II 



HOCH CCH, 



\ / ^Citiaui-ine 



CH, 



CHi CH, CH, CH, 



11 II 



HOOCC=CHCH=CHC=CHCH=CHCH=CCH=CHCH = CCOOH 



Crocetin 



CH, CH, CH, CH, 



II II 



HOOCCH=CHC = CHCH=CHC=CHCH = CHCH=CCH = CHCHr=CCH=CHCOOCH, 



Bixin 



Cyclization can take place at both ends or at one end of the chain. By 

 oxidative degradation the chain may be shortened. On the other hand, the 

 introduction of various oxygenated groups gives rise to a series of derivatives. 

 The carotenes (carrot, lemon, orange, apricot, etc.) and lycopene (tomato) are 

 hydrocarbons, whilst cryptoxanthin (fruit of Chinese lantern plant, egg yolk, 

 etc.), rubixanthin (berries of the wild rose, etc.), xanthophyll (green and 

 yellow leaves, dandelion flowers, eggyolk, etc.), lutein (pumpkin, many yellow 

 flowers, etc.), zeaxanthin (maize grain, egg yolk, etc.), flavoxanthin (buttercup 

 flowers, etc.), violaxanthin (laburnum flowers, etc.), taraxanthin (dandelion 

 flowers, etc.) and fucoxanthin (algae of the genera Fiicus, etc.) are alcohols. 

 Similarly, rhodoxanthin (berry of the yew-tree, etc.) is a diketone, capsanthin 

 (red pepper) and capsorubin (red pepper) are hydroxy-ketones and crocetin 

 (saffron or the pigment from Crocus pollen, etc.) is an acid. Carotenoid 

 pigments are widely distributed in the biosphere and will be found, no 

 matter whether one examines plants or animals, algae or bacteria. 



REFERENCES 



Deuel, H. J. (1951) Carotenoids and related compounds, in The Lipids, vol. I, 

 Interscience, New York. 



Goodwin, T. W. (1952), The Comparative Biochemistry of the Carotinoids. Chap- 

 man and Hall, London. 



Karrer, p. & JucKER, E. (1948) Carotinoide. Birkhauser, Basel. 



