116 AROMATIC COMPOUNDS [ch. 



material : magenta Snapdragon {Antirrhinum majus)^ brown Wallflower {Cheiranthus 

 Cheiri), crimson Paeony {Paeonia ojfficinalis\ magenta " Cabbage " Rose, Violet 

 ( Viola odorata\ but the majority of coloured flowers will serve equally well. 



Though the above represent the reactions and solubilities given by 

 the greater number of anthocyan pigments, it will be found that all are 

 not alike in these respects. Thus, for instance, the pigments of certain 

 blue flowers, e.g. blue Larkspur {Delphinium), Cornflower {Centaur ea 

 Cyanus) and blue Columbine {Aquilegia) are neither soluble nor lose 

 their colour in alcohol, but are soluble in water. 



There is a small group of plants belonging to some allied natural 

 orders, of which the anthocyan pigments give chemical reactions still 

 more different from the general type already described, though they 

 nevertheless resemble each other. Such, for instance, are the pigments 

 of various genera of the Chenopodiaceae [Beet {Beta), Orache {Atriplex)\ 

 Amarantaceae {Amaranthus and other genera), Phytolaccaceae {Phyto- 

 lacca) and Portulacaceae {Portulaca). These anthocyan pigments are 

 insoluble in alcohol but soluble in water : they give a violet colour with 

 acids, red to yellow with alkalies, and a red precipitate with basic lead 

 acetate. 



Anthocyan pigments may also occur in leaves, and this is very obvious 

 in red-leaved varieties of various species such as the Copper Beech, the 

 Red-leaved Hazel, etc. 



Expt. 112. Extraction of anthocyan pigment from the Red-leaved Hazel. Extract 

 some leaves of the Blood Hazel {Corylus Avellana var. rubra) with alcohol. Filter off 

 and evaporate the solution to dryness. Add water. Pour a little of the crude mixture 

 in the dish into a test-tube and add ether. There will be a separation into a green 

 ethereal layer containing chlorophyll, and a lower water layer containing anthocyan 

 pigment. Filter the extract remaining in the dish and with the filtrate make the 

 tests already given in Expt. Ill ic)-{i). 



The leaves of the Copper Beech {Fagus sylvatica var. purpurea) can also be 

 used. 



In many flowers, the cells of the corolla may contain, in addition to 

 anthocyan, yellow plastid (see p. 40) pigments. The colour of the petals 

 is in these cases the result of the combination of the two, and is usually 

 some shade of brown, crimson or orange-red, as in the brown-flowered 

 variety of Wallflower {Cheiranthus Cheiri), the bronze or crimson 

 Chrysanthemum, the brown Gaillardia and the orange-red flowers of 

 Nasturtium {Tropaeolum majus). The presence of the pigments can be 

 demonstrated by their different solubilities (see Expt. 110). 



Anthocyanins and anthocyanidins have been isolated from various 



