GLUCOSIDES 89 



Sinalbin, C3oH420i5N2S2, from white mustard seeds, when 

 hydrolyzed by myrosin, yields glucose, sinalbin mustard oil (a 

 paraoxybenzyl derivative of allyl isosulfocyanide) and sinapin 

 acid sulfate; according to the equation 



C3oH4 2 Ol5N2S2~l~H2O = CGHnjOG^CyHyO NCo 

 Sinalbin Glucose Sinalbin mustard oil 



+Ci 6 H 2 40 5 N-HS04. 



Sinapin acid sulfate 



The sinalbin mustard oil may be represented by the formula 

 HO^ ^>CH 2 NCS. Hydrolysis of the sinapin acid sulfate con- 

 verts it into sinapinio acid, C 6 H 2 OH-(OCH 3 ) 2 -CH = CH-COOH, 

 choline, N(CH 3 ) 4 C 2 H4OH (see page 152), and H 2 S0 4 . It is, 

 therefore, a very complex glucoside. 



THE DIGITALIS GLUCOSIDES 



The five, or more, glucosides which are present in the leaves 

 and seeds of the foxglove (Digitalis purpurea') have been exten- 

 sively studied, as they are the active principles in the various digi- 

 talis extracts which are used in medicine as a heart stimulant. 

 Digi toxin, C34Hs4Oii, which is the most active of these glu- 

 cosides in its physiological effects, when hydrolyzed, yields digit- 

 oxigenin, C 22 H3 2 O4, and a sugar having the formula CeHi 2 04, 

 which is known as " digitoxose " and is supposed to be a dimethyl 

 tetrose. 



Digitalin, C^HseOn, is also strongly active. When hydro- 

 lyzed, it yields digitaligenin, C 22 Hio0 3 , glucose, and digitoxose. 



Digitonin, C54Hg 2 O 2 8, constitutes about one-half of the total 

 glucosides in the extract which is obtained from most species of 

 the digitalis plants. It is much less active than the others. It is a 

 saponin (see page 90) in type. On hydrolysis, it yields 2 mole- 

 cules of glucose, 2 of galactose, and one of digitogenin. 



Gitonin, C49HgoO 2 3, containing 3 molecules of galactose, one 

 of a pentose sugar, and one of gitogenin; and gitalin, C 2 gH48Oio, 

 containing digitoxose and gitaligenin, have also been isolated from 

 digitalis extracts. 



The structural arrangement of the characteristic groups in 

 these glucosides has not yet been definitely worked out. 



