251: 



The Production of Anthocyanins and Anthocyanidins. — Part III.'* 

 By Arthur Ernest Everest, D.Sc, Ph.D. 



(Communicated by Dr. F. W. Keeble, F.E.S. Received April 9, 1918.) 



The work of Willstatter.f of Willstatter and Mallison,:]: and of Willstatter 

 and Zechmeister,§ that has followed upon the proposal by the present 

 author of a ^structural formula for the anthocyan piginents,|| has clearly 

 demonstrated the correctness of the formula proposed, and of the conclu- 

 sions of the present author as to the relationship that exists between the 

 anthocyan and flavonol groups, exemplified thus : — 



Cl 



I 



O OH O OH 



H0-/\/ \c— <^ \0H HO— /\^\c— <^ ^OH 



LoF~oH ■ 



|, N / 



V OK 



I c I c 



HO II HO I 



O H 



Flavonol (Myricetin). y Anthocyan (Delphinidin). 



Although it has thus been proved that anthocyanidins can be produced 

 from flavonols, and that the flavonol glucosides pass, likewise, to antho- 

 cyanins, it does not of necessity follow that the anthocyan pigments are 

 thus formed in plants and flowers, although this is probable, and in the 

 present paper chemical evidence is produced which strengthens this proba- 

 bility. 



It was with a view to an examination of some points that may prove of 

 value in connection with the tracing of the formation of the anthocyan 

 pigments in Nature that the author began the investigations, of which this is 

 a preliminary announcement. In view of the fact that the work, which was 

 begun during the summer of 1914, has had of necessity to stand aside, and 

 must continue to do so for some time, and of the publication of further work 

 by Willstatter and his collaborators,ir some of which touches upon the same 

 ground, the author feels that the publication of the present preliminary 

 observations will not be out of place. 



* Parts I and II appeared in these ' Proceedings,' B, vol. 87, p. 444 ; vol. 88, p. 326 

 (1914). 



t ' Sitzber. K. Preuss. Akad. Wias.,' 1914, p. 402. 



I Ibid., p. 769. 

 § Ibid., p. 886. 



II ' Roy. See. Proc.,' B, vol. 87, p. 444 (1914). 



T Willstatter and Weil, ' Annalen,' vol. 412, p. 178 (1916). 



X 2 



