346 



Journal of Agricultural Research 



Vol. XIII, No. 7 



cotton flowers of G. arboreum L., from which, however, isoquercitrin and 

 quercetin were isolated. Ouercimeritrin, another glucosid, could be 

 isolated only from one of the types mentioned — namely, the Egyptian 

 cotton. 



As a result of these investigations, the writers found that the petals of 

 Upland cotton and the flowers with petals removed contained appreciable 

 amounts of quercimeritrrn. Very small amounts of isoquercitrin could 

 also be found in the petals. So far, no gossypitrin or gossypetin could be 

 isolated. The leaves were collected from plants grown at Brownsville, 

 Texas, and the flowers from plants at Tallulah, Louisiana. 



The results showing the character and distribution of color substances 

 in the different types of the cotton plant are compiled in Table I, 

 which shows clearly the chemical distinction among the different types 

 of the cotton plant, as recently indicated by Perkin. 



Table I. — Distribution of glucosids and their products of hydrolysis in cotton 



For the sake of comparison, the chief properties of the glucosids 

 isolated from the cotton plant and their products of hydrolysis, compiled 

 largely from the work of Perkin, are described below. 



The glucosids querdmeritrin and isoquercitrin are isomeric com- 

 pounds with the fonnula Q^^2.(f^^. Isoquercitrin (5) has been found 

 only in the cotton plant, while querdmeritrin (j) has also been found 

 associated with prunitrin in the bark of a species of Prunus, closely 

 related to Prunus emarginata. 



QuERCiMERiTRiN (j) Crystallizes with three molecules of water from 

 pyridin and water in small glistening plates of a bright-yellow color. 

 They melt in a very pure state at 247 ° to 249° C, are almost insoluble 

 in cold water or alcohol, but are rather easily soluble in the hot sol- 

 vents. The acetyl derivative consists of needles that melt at 214° to 

 216° C. and are difficultly soluble in boiling alcohol. 



