172 GLUCOSIDES 



CH 2 OH CHOH CH CHOH CHOH CH . OH + HOC 6 H 4 CH.,OH 

 Glucose Saligenin 



-O 1 



CH 2 OH CHOH CH CHOH CHOH CH . O . C^CH^OH + H 2 O 

 Salicin 



O 



CH 2 OH CHOH CH CHOH CHOH CH . OH + HOC 6 H 4 OH 



CH.i 



CHjOH CHOH CH CHOH CHOH CH . O . C 6 H 4 OH + H 2 O 



Arbutin 



CH 2 OH CHOH CH CHOH CHOH CH . OH + HO C H 



b 



Glucose Mandelonitrile 



O j C 6 H ts 



= CH 2 OH CHOH CH . CHOH CHOH CH O CH + H 2 O 



L 



Mandelonitrile glucoside 



Moreover, the constitution of amygdalin itself would ap- 

 pear to be best represented by the formula * : 



CH 2 OH CHOH CH CHOH CHOH CH . O . CH a CHOH CH CHOH CHOH CH . O . CH 



and, by analogy, phaseolunatin is regarded as the glucose 

 ether of acetone cyanhydrin (see p. 1 82). 



In some cases the natural glucosides have been actually 

 synthesized ; thus salicin has been obtained by the reduction 

 of the corresponding aldehyde glucoside, helicin : 



C a H n O 6 .O.C 6 H 4 CHO + 2H = C 6 H U O S .O. C 6 H 4 CH 2 OH 



the helicin itself having been synthesized from glucose and 

 salicylic aldehyde. 



Identification. 



For the identification of glucosides the character of the 

 cleavage products are relied upon ; these products, with the 



* Auld: "J. Chem. Soc., Lond.," 1908, 93, 1279. 



