80 CHEMISTRY OF PLANT LIFE 



Hesperitin 



HO/V- CH = CH C 

 CH 3 ol J O 



THE ALCOHOL GLUCOSIDES 



Salicin, CisHigOT (glucose +saligenin, or o-oxy benzyl alco- 

 hol) is found in the bark, leaves, and flowers of most species of 

 willow, the proportion present depending upon the season of the 

 year, and the sex of the tree. It is used as a remedy against 

 fevers and rheumatism, causing less digestive disturbances than 

 the salicylic acid which is the oxidation product of saligenin and 

 which is sometimes used as a remedy for rheumatism. 



Coniferin, CieH^Og (glucose and coniferyl alcohol), is found 

 in the bark of fir trees. The coniferyl alcohol obtained from 

 coniferin by hydrolysis can be easily oxidized to vanillin, and is, 

 therefore, the source for the artificial flavoring extract used as a 

 substitute for the true extract of the vanilla bean. 



Populin, C2oH22O 8 (glucose+saligenin+benzoic acid), found 

 in the bark of poplar trees, is used in medicine as an antipyretic. 

 It can be hydrolyzed, by a special enzyme, into salicin and benzoic 

 acid. 



The structure of the two typical closed-ring alcohols which are 

 present in these glucosides is indicated by the following formulas; 



Coniferyl alcohol 

 Saligenin CH = CH CH 2 OH 



ox 



