VIl] 



OXIDIZING ENZYMES 



Expt. 105. Demonstration of the presence of anthocyan and plastid pigments 

 together in petals (see also Expt. 100). Extract petals of the brown-flowered variety of 

 Wallflower with alcohol. Filter, and evaporate the extract to dryness. Take up 

 with water and add ether. Pour the mixture into a separating funnel. The plastid 

 pigment will pass into solution in the ether, and the anthocyan pigment will remain 

 in the water. Test the aqueous solution as in Expt. 101 (c)-(t). 



The following may be used as material : ray florets of bronze or crimson Chrys- 

 anthemum, ray florets of Gaillardia,&ud orange-red flowers of Nasturtium (Tropaeolum 

 majus}. 



Anthocyanins and anthocyanidins have been isolated from various 

 species. The pigments themselves with one exception have not been 

 obtained in the crystalline state, but crystalline compounds with acids 

 have been prepared both of the glucosidal and non-glucosidal forms. 



All the pigments so far described appear to be derived from three 

 fundamental compounds, pelargonidin, cyanidin and delphinidin, of 

 which the chlorides are represented thus : 



OH H 



Pelargonidin chloride 



Cyanidin chloride 



OH 



Delphinidiu chloride 



It has been suggested, at least in the case of cyanidin, the pigment 

 of the Cornflower (Gentaurea Cyanus), that the pigment itself is a neutral 

 substance, purple in colour and of the following structure (Willstatter, 

 33, 36): 



