54 CAROTINOIDS AND RELATED PIGMENTS 



plastids arc always characterized by an ab-ence of chlorophyll, the 

 leaves being yellow or golden yellow in color. Several investigators 

 have studied the pigmentation of such plants in relation to the yellow 

 chrom'olipoids which characterize the chloroplastid. Thudichinn 

 (1869). many years ago, observed the relation between the pigment of 

 the carrot root and that in the yellow leave- of Coleus, and included 

 them both in his group of luteins. Dippel 11878) found that the 

 spectroscopic absorption bunds of the piment extracted by alcohol 

 from yellow leaves corresponded with those of the yellow pigment 

 which hi 1 found to be present in Kraus' cyanophyll layer from green 

 leaf extracts. Dippel called tin- pigment xanthin. 



Tammes |1900) and Kohl i!902gi lir.-t -ought to show the relation 

 of the pigment of such leave- to carotinoids. Tamme- found that the 

 plastids of yellow leave- gave positive carorinoid reaction- with con. 

 H,SO 4 , con. HXO... and with HCl containing phenol and with bromine 

 water, when the leaves were tirst dried. Yellow leaves in which the 

 chromoplastids had disintegrated failed to give these reactions. When 

 examined after -ubmittin-j; the leave- to the Moli-ch alkali cry.-tailiza- 

 tion method brownish yellow crystals of variola -hape- were ob-erved 

 in each of the following cases: 



1. Aiicuba japonica Thiinb. (Japanese Aokiba). 



2. Elaeagnus latifolia li. 



3. Euonymous japonicus L. variety vulphwrea '.Japanese .-pindlr tree). 



4. Sainbitntfi nii/ni I.., variety awrea. < Kuropean eldi 



Kohl (1902g) substantiated the-e re-ults, also using the Molisch 

 method, and in addition obtained carotinoids in the following plants 



with naturally yellow leav 



1. Abutilon n<r;ns,tm (Flowering maple). 



2. Bctula species (Birch). 



3. Spiroea species, variety nun a. 



Kohl made a more exhaustive study of the pigment of yellow elder 

 leaves I S,, //,/,,/,//* nnjra foliix liittix* and found that the dilute alco- 

 holic KOH extract of the leaves gave up only a small part of the pig- 

 ment to ether. The ether extract thus obtained gave the carotin 

 spectrum, but the pigment remaining in the alkaline alcohol layer 

 showed only end absorption of the spectrum. He believed that this 

 pigment was due in part to the (3 xanthophyll of Tschirch (1887), and 

 in part also to a new pigment which he called phyllofuscin. which dif- 

 fers from (3 xanthophyll in being partly extracted from its aqueon- 

 solution by ether. It seems likely that Kohl was dealing here with 



