172 GLUCOSIDES 



CH2OH CHOH CH CHOH CHOH CH . OH + HOC8H4CH,,OH 

 Glucose Saligenin 



I I 



= CH2OH CHOH CH CHOH CHOH CH . O . CgH^CHjOH + H^O 

 Salicin 



I I 



CH.OH CHOH CH CHOH CHOH CH . OH + HOCgH^OH 



Glucose Hydroquinone 



-O- 



= CH2OH CHOH CH CHOH CHOH CH . O . C^H.OH + H.O 

 Arbutin 



o C«H, 



II I 



CH2OH CHOH CH CHOH CHOH CH . OH + HO— C— H 



Glucose Mandelonitrile 



== CH„OH CHOH CH . CHOH CHOH CH— O- 



" - CH + HgC 



Mandelonitrile glucoside 



Moreover, the constitution of amygdalin itself would ap- 

 pear to be best represented by the formula * : — 



O CgHs 



CH2OH CHOH CH CHOH CHOH CH . O . CH2CHOH CH CHOH CHOH CH . O . CH 



' O ' iK 



and, by analogy, phaseolunatin is regarded as the glucose 

 ether of acetone cyanhydrin (see p. 182). 



In some cases the natural glucosides have been actually 

 synthesized ; thus salicin has been obtained by the reduction 

 of the corresponding aldehyde glucoside, helicin : — 



CeHiiOg.O.CgH^CHO + 2H = CbHuO^.O. CgH.CHoOH 



the helicin itself having been synthesized from glucose and 

 salicylic aldehyde. 



Idoitification. 



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. 



