88 AROMATIC COMPOUNDS AND [CH. 



OH 



a ; 



OH OH OH 



Resorcinol Catechol Hydroquinone 



Hydroquinone has been found in the free state in the leaves and 

 flowers of the Cranberry (Vaccinium Vitis-Idaea). As a glucoside, 

 known as arbutin, it occurs in many of the Ericaceae (see also p. 151). 



Phloroglucin is the only member of the trihydroxy phenols found 

 uncombined in plants. It is very widely distributed in the combined 

 state in various complex substances (Waage, 27). 



OH 



Phloroglucin 



AROMATIC ALCOHOLS AND ALDEHYDES. 



The following are some of the better known compounds of this group: 

 Saligenin, or salicylic alcohol, in the form of the glucoside, salicin, 

 occurs in the bark of certain species of Willow (Salix), and in the 

 flower-buds of the Meadow-sweet (Spiraea Ulmaria). Salicin is hydro- 

 lyzed by an enzyme contained in the plant in which it occurs, into 

 saligenin and glucose (see also p. 152). 



CH 2 OH 



OH 



Saligenin 



Salicylic aldehyde occurs in species of Spiraea and other plants. 



Coniferyl alcohol, as a glucoside, coniferin, is found in various 

 conifers and also in Asparagus (Asparagus officinalis). Coniferin is 

 hydrolyzed by dilute acids or by enzymes (emulsin) into coniferyl alcohol 

 and glucose (see also p. 151). 



OCH. 



OH 



Coniferyl alcohol 



