258 



Dr. A. E. Everest. 



for the purification of cyanin chloride from the Cornflower.* As Willstatter 

 and Weil's method of purification would save considerable time, it was tested 

 with the above crude product, and found to be very satisfactory, viz. : The 

 moist precipitate of the anthocyan pigment, either crude or preferably after 

 one reprecipitation from alcoholic hydrochloric acid by means of ether, was 

 dissolved in 0"04-per-eent. aqueous HCl (for the total precipitate from 

 25 grm. dry petals m. 50 c.c. were used), the solution filtered, and the filtrate 

 mixed with half volume of 96-per-cent. ethyl alcohol, and one volume of 

 4-per-cent. hydrochloric acid, then allowed to stand several days in a dish 

 loosely covered with filter paper. Under these conditions well-formed 

 crystals separated which were collected, washed with 7-per-cent. aqueous 

 hydrochloric acid, and air dried (25 grm. petals gave 1"3 grm. crystals). 



The pigment when recrystallised in this way, separated with splendid 

 regularity as deep red, clean cut, hexagonal or tetrahedral plates. 



The properties of the crystalline chloride have been carefully noted and 

 compared with those of Willstatter and Weil's violanin chloride, and the 

 result of the investigation leaves no doubt that the products are identical. 



In view of the discovery in the alcohol-ether liquors of the presence not 

 only of myricetin, but also of another flavone derivative which is capable of 

 producing an anthocyan by reduction, an attempt was made to see whether 

 any indication of the presence of other anthocyanins could be detected in 

 the plant extract. To this end, the alcoholic hydrochloric acid extract from 

 1 grm. of petals was carefully fractionally precipitated by ether, the pre- 

 cipitate from each fraction being collected, dissolved in water, made very 

 faintly acid, then tested in respect of the colour reaction given with ferric 

 chloride. In all, nine fractions, which included the whole of the red pigment 

 present, were made, all were treated in exactly the same way, and direct 

 comparison of the colour reactions given by all nine fractions was made at 

 the same time. No difference of any kind could be observed in the colours 

 produced, which in every case were clear pure blue. This points to the 

 absence of the cyanidin glucosides, cyanin, mekocyanin, ideein, asterin, and 

 ehrysanthemin, also to the absence of the giucoside derivatives of delphin- 

 idin, myrtillin, althein, the anthocyanin from Vitis rifaria, and possibly 

 ampelopsin, for all of these pigments produce a violet coloration under the 

 conditions of the experiment described above, but does not preclude the 

 presence of other anthocyanins which either give blue, or violet-blue, or do 

 not give any coloration under the above conditions. 



The quantities of material available were not sufficient to allow of further 

 investigations on these lines. 



* ' Annalen,' vol. 401, p. 189 (1913). 



