﻿BOTANICAL GAZETTE 



the cause of variation in the color of 

 been established or made very probable. 



The anthocyanins are characterized 

 teric nature. Their strong basic charac 

 they form oxonium salts with tetravaler 

 best basis for their isolation and purificat 

 crystalline bodies with various organic 



5 bearing these pigments, hav< 



.free 



the fact that with acids 

 ?his character forms the 

 this basis they form good 

 ic acids. The chlorides 

 ains is due to their poly- 



were most used. The acid character of the anthocyanins is due to t 

 phenolic nature. This was formerly used as the basis for isolation by the 

 precipitation as lead salts, but it is undesirable, since many other substances 

 fall out with the pigments. The acid salts are red, the neutral anthocyanins 

 violet, and the alkali salts (for such anthocyanins as form them) are blue. In 

 neutral and still more frequently in alkaline condition the anthocyanins become 

 colorless. This is due to an isomerization, and not to a reduction, as is gen- 

 erally assumed. This is suggestive in explaining the loss of color by flowers 

 under certain conditions." Upon acidulation the color returns. In plants the 

 anthocyanins exist entirely or nearly so as glucosides. Brief heating of the 

 anthocyanins with 20 per cent HC1 splits them into glucose and the cor- 

 responding anthocyanidins. The following are some of the studied antho- 

 cyanins and their splitting products. 



(G 7 H 31 0 1S C1 4 H,0) 

 Delphinin 



(C 4I H 39 0*C1 iaHdO) 



(C 23 H 25 O ia Cl 4 H,0) 

 Marvin 



(C 29 H 35 O l7 Cl 8H 2 0) 



Pelargon 

 Delphinii 



Deep col 

 grape 

 Wood m: 



consolida 



(C I5 H„0 6 Cl+2 glucose) 



(CxsHnOsCl+2 gluo 

 Delphinidin 

 (C IS H„0 7 Cl+2 gluo 

 + 2 p oxybenzoic 

 Onidin* 



(C I7 H IS O v Cl-r-i glucose) 



acid) 



Malvidin* 

 (C I7 H I5 0 7 Cl+2 



color, melting or d 



idins have been tabula 

 fication, put significant 

 5 chemical training. 



) the hands of plant breeders of mod- 



stoffen. Zeitschr. 



