REGENT CHEMICAL INVESTIGATIONS OF THE 

 ANTHOCYAN PIGMENTS AND THEIR BEARING 

 UPON THE PRODUCTION OF THESE PIGMENTS 

 IN PLANTS. 



By ARTHUR ERNEST EVEREST, M.Sc, Ph.D. 

 {Lecturer in Chemistry, University College, Reading). 



The relationship— if any — which exists between the red, purple and 

 blue plant pigments (Anthocyans) and those of the yellow plant pig- 

 ments which are of the flavone or flavonol class is of considerable 

 interest to students of genetics. 



Until quite recently all ideas upon this subject were based of neces- 

 sity upon evidence obtained from botanical investigation, as reliable 

 chemical investigation upon this subject was entirely lacking. At last 

 however definite chemical evidence bearing upon the relationship 

 existing between these two important classes of naturally occurring 

 pigments has been obtained, and in the present paper the author 

 summarises briefly the important points that have been investigated, 

 and points out their bearing upon the theories previously put forward. 



Up to the present the consensus of opinion has been in favour of 

 the theory that the anthocyans are produced by oxidation of yellow 

 pigments of the Havone or flavonol series. The fact that these ideas 

 have failed to stand the test of chemical investigation — in every case 

 that has been examined in a chemically satisfactory manner — must now 

 be realised. 



Attacking the problem with a view to establishing the chemical 

 nature and structure of the anthocyan molecule, Willstatter and Everest 

 (Liebig's Annalen, 1913, 401, 189) investigated a number of these pig- 

 ments, and in particular that of the corn-flower. Their results contain 



