78 



THE ISOLATION AND 



[CH. 



of the pigment in wood spirit ; on slow evaporation the pigment separates 

 out in beautiful flat prisms. Myrtillin gives, on hydrolysis, one molecule 

 of glucose and one molecule of myrtillidin C 16 H 12 7 . Myrtillin was 

 also isolated from flowers of the Hollyhock (Althaea rosea). 



The following anthocyanins were also isolated, but no details are 

 given of the methods. 



The flower-pigment of Delphinium delphinin which gives, on 

 hydrolysis, two molecules of glucose, two molecules of p-oxybenzoic 

 acid and one molecule of delphinidin C 15 H 10 7 . 



The flower-pigment of Pelargonium pelargonin which gives, on 

 hydrolysis, two molecules of glucose, and one molecule of pelargonidin 



""^JsHjijOg 



The flower-pigment of Malva -malvin which gives on hydrolysis 

 malvidin C 17 H 14 7 . 



The chlorides of pelargonidin, oenidin and delphinidin are described 

 as crystalline salts, insoluble in water, but soluble in alcohol. In the 

 glucosidal form, they give, with the exception of delphinidin, colourless 

 isomers in water solution. The anthocyanidins isomerise less readily. 

 The isomerisation is said to take place according to the following 

 equation : 



C 15 H 10 7 HC1 + H 2 = HC1 + C 15 H 12 8 



In alkali melts of the pigments, the following decompositions were 

 found to take place: 



Cyanidin gave phloroglucin and protocatechuic acid. 



Pelargonidin gave phloroglucin and ^-oxybenzoic acid. 



Delphinidin gave phloroglucin and gallic acid (not isolated in pure 

 state). 



As a result of these further researches Willstatter then suggests 

 that for the formula of cyanidin chloride the choice lies between : 



OCl 



OC1 



I. 



HO 



OH 



OH 



