CHAPTER XI 



Carotenoids of known structure containing 

 hydroxy I groups 



I. LYCOXANTHIN C^oHggO 



History and Occurrence 



1936 In the course of investigations on lycopene from Solatium Dulcamara, 

 Zechmeister and von Cholnoky^ isolate two new phytoxanthins, 

 lycoxanthin and lycophyll. Lycoxanthin also occurs in Solanum esculen- 

 tum and Tamus communis*' ^. 



Preparation^ 



17 Kg of fresh berries of Solanum Dulcamara are dehydrated with ethanoland 

 extracted with ether at room temperature. After evaporation of the solvent, the 

 pigment mixture is dissolved in benzene and chromatographedoncalciumhydroxide. 

 This procedure is repeated several times and the pigment is finally recrystallised 

 from a mixture of benzene and methanol. The yield was 125 mg lycoxanthin, 920 

 mg lycopene and 9 mg lycophyll. 



Chemical Constitution 



\V \V 



y I I I I V 



CH HC-CH=CH-C=CHCH=CH-C=CHCH=CHCH=C-CH=CHCH=C-CH=CHCH CH 



HOCH C-CHa HaC-C CHg 



\ / Lycoxanthin \ y^ 



CHg CH2 



Owing to the small amount of material available, the elucidation of the 

 constitution of lycoxanthin presented difficulties and could not be carried 

 through completely. From the similarity of the absorption maxima of lyco- 

 xanthin and lycopene, Zechmeister and von Cholnoky^ concluded that the 



According to E. Lederer, Bull. Soc. chem. Biol. 20 (1938) 613, Polystigma rubrum 

 also contains lycoxanthin besides an acidic pigment. 



References p. 214-21J. 



