544 VI. CAROTBNOIDS AND RELATED COMPOUNDS 



CrOj 



CH, CH,, CHj CH: 



HjC CH, 



\ / 

 C 



// hhhIhhhIhhhhIhhhIhhh 

 HC c-c:c-c:C'C:C'C:c-c:c-C;C-C:C-c:C'C:c- C=0 



HzC C I 



\ / \ I 



C CH,! 



L____"i J 



Lyropenal 



+ CM, • CO • CH... CH>. CH : CICH,), 

 Meth>lheptenone 



CrOj 



CHj \ CH, CH, CH, 



HHH IhHH IhHHH IhHhI HHH 



0=C-c:c-c:c-c:c-c:C'C:C-C:C-C:C-C:C-C:c- C=0 

 Bixiii dialdeh\de 



+ CH,- CO • CHj- CH,. CH : C{CH,)j 

 Meth\lheptenone 



b. Occurrence. Lycopene is primarily a plant pigment. The most 

 practical source of the pigment is the tomato {Lycopersicon esculentum)^" 

 in which yields as high as 20 mg. per kilogram of fresh tomato, or about 

 150 mg. per kilogram of tomato puree, have been reported. Lycopene has 

 been isolated from a number of fruits, including the watermelon iCitrullus 

 vulgaris Schrad.),^^''''^'^ the apricot {Prunus armeniaca L.),^^^ and the Jap- 

 anese persimmon {Diospyros kaki L.)."^ Matlack-'-- made the interesting 

 observation that the principal pigment in the Foster and Marsh varieties 

 of pink grapefruit (Citrus paradisi) is lycopene; /3-carotene was likewise 

 shown to be present in the latter case. 



Fairly high concentrations of lycopene occur in rose hips^^^-^^^'^^^"^^^ of a 

 variety of species, including Rosa canina (dog rose), R. eglanteria (sweet- 

 briar), R. damascena (damask rose), and R. rugosa Thumb, (red rugosa 

 rose). This carotenoid occurs in the berries of the Tamus communis 

 (black brj^ony),--^ and of the bitter nightshade (Solanum dulcamara L.).^^^ 

 Other sources include the fruit of the lily-of-the-valley (ro/i/'a//a'ia rnajalis),^* 

 the red-berry bryony climber {Bryonia dioica),^'^ the cocaine tree {Ery- 

 throxylumnovogranatense) , that of the cluster palm (Actinophloeus macarthuri 



2" M. B. Matlack, J. Biol. Chem., 110, 249-253 (1935). 

 2" H. H. Escher, Helv. Chim. Acta, 11, 752-754 (1928). 

 22^ R. Kuhn and C. Grundmann, Ber., 67, 1133 (1934). 

 226 F. C. Jacoby and F. Wokes, Biochem. J., 38, 279-282 (1944). 



226 L. Zechmeister and L. v. Cholnoky, Ber., 63, 422-427 (1930). 



227 L. Zechmeister and L. v. Cholnoky, Ber., 63, 787 790 (1930). 



