GLUCOS1DES 79 



THE PHENOL GLUCOSIDES 



Arbutin, C^HieOj, is obtained from the leaves of the bear 

 berry (Arctostaphylos uva-ursi), a small evergreen shrub. When 

 hydrolyzed by mineral acids or emulsin, it yields glucose and 

 hydroquinone. 



Hydroquinone has strongly antiseptic properties. Arbutin is 

 both an antiseptic and a diuretic, and is used in medicine. 



Phloridzin, C2iH24Oio, is found in the bark of apple, pear, 

 cherry, plum, and similar trees. Mineral acids (but not emulsin) 

 hydrolyze it to glucose and phloretin (CisHuOs), according to the 

 equation 



CH 3 



I 

 C 2 iH 24 Oi +H 2 = C 6 Hi 2 6 + (OH) 3 C 6 H 2 - CO - CH - C 6 H 4 OH. 



It is used in medicine as a remedy for malaria, having marked 

 anti-periodic properties. 



Glycyphyllin, C2iH24Og, found in leaves of Smilax, yields 

 rhamnose and phloretin, when hydrolyzed. 



Iridin, C24H 2 6Oi3 (glucose and irigenin), found in root stocks 

 of Iris, is used in medicine as a cathartic and diuretic. 



Baptisin, C26H32Oi4-9H20 (two rhamnose and baptigenin), 

 found in roots of wild indigo (Baptisia) , has strong purgative 

 properties. 



Hesperidin, CsoHeoCb? (one rhamnose+two glucose+hes- 

 peritin) , is found in the pulp of lemons and oranges. 



The characteristic phenol group which is present in these 

 glucosides has the following structural formula, in each case, the 

 X indicating the H atom which is replaced by the sugar molecule 

 to form the glucoside: 



Phloretin 



/\ - C CH 



II I 

 HOI JOH CH 3 



