332 The Production of Anthocyanins and Anthocyanidins. 



From the specimen of rutin supplied by Prof. Perkin, a sample of the 

 crystalline pigment was prepared according to his instructions, and from this 

 also the red pigment obtained and subjected to similar treatment. It yielded 

 exactly similar results. 



This case is of particular interest, for, if the disaccbarose is attached to the 

 flavonol molecule in the correct position, the pigment produced should be 

 identical with cyanin. 



For comparison with the above glucoside pigments, the same series of 

 experiments was carried out with cyanin chloride, and gave exactly similar 

 results. 



From the red pigment obtained by reduction of quercitrin (Kahlbaum) or 

 from rutin, the non-glucoside pigment was obtained by hydrolysis, collected, 

 dissolved in a mixture of equal parts by volume of ethyl alcohol (absolute) and 

 2N hydrochloric acid (aqueous), and of the solution obtained one part was 

 retained for comparison, the other shaken with excess of finely powdered 

 calcium carbonate to remove acid. The colour chans;ed to violet, and after 

 filtration and warming became decolorised — lost all violet colour, only faint 

 brownish-yellow colour remaining. On acidification with 2-3 drops of 

 concentrated hydrochloric acid and warming, the red colour returned, but not 

 quantitatively. A comparative experiment using cyanidin chloride gave 

 exactly similar results. 



In solution — even faintly acid — this non-glucoside pigment is not so stable 

 as are the glucosides above mentioned : thus, after standing; for a week the 

 colour is considerably diminished, and this diminution is due to destruction. 

 Cyanidin, however, behaves similarly, if somewhat impure. 



The cyanin and cyanidin chlorides used were obtained from a specimen of 

 cornflower pigment containing about 10 per cent, of pure pigment. 



The author desires to express his thanks to Prof. A. G. Perkin, F.R.S., for 

 supplying him with the sample of rutin used in some of the above 

 experiments. 



