Wakeman—Pigments of Flowering Plants. 
869 
Oenidin,—a dimethyl ether of delphinidin. 
The pigment from grapes had been separated in a more or 
less impure state many times before Willstaetter undertook his 
study of anthocyanin pigments. Mulder, 1 in 1856 obtained the 
pigment in the form of a bluish black mass, Mawmene, 2 in 1856, 
obtained the same substance and named it t ‘ oenocyanin. ” In 
1858 Glenard obtained the pigment as an amorphous substance 
which he called ‘ ‘ oenolin ’ ’ and to which he assigned the formula 
C 20 H 20 O 10 . Gautier 4 made several investigations of the coloring 
matter of grapes, continuing his studies for a number of years. 
Gautier traced a close relationship between the grape pigment 
and the tannins. Willstaetter, 5 in 1915, found the pigment to 
exist in the form of the glucoside oenin in Vitis vinifera. To 
the product of hydrolysis he gave the formula above. 
Oenidin is an isomer of rhamnazin, a dimethyl ether of quer¬ 
cetin. 
Malvinidin,—a dimethyl ether of delphinidin. 
OCH, 
1 Die Chemie des Wines, 44, p. 228. 
2 Le Travail des Vins. 
3 C. r., 47, p. 268; Ann. Chim. Phys., (3) 54, p. 366. 
4 C. r., 86., p. 1507; 87, p.' 64; 114, p. 623. 
5 Ann. 408, p. 87. 
