CLASSIFICATION 



267 



CH 2 CH 



CH 2 CH CH = CH a 

 CH 2 CH 2 



CHOH CH- 

 CH, 



-N 



Quinine 



from which it will be seen to contain a quinoline ring. 



The constitution of strychnine and brucine has not yet 

 been determined, though possible formulae have been suggested 

 by Perkin and Robinson.* 



V. Isoquinoline Alkaloids. These may be divided intp the 

 three following groups : 



(a) Papaverine group, including Papaverine, Narcotine, 



Laudanosine, etc., closely allied to which are 



Hydrastine and Hydrastinine from Hydrastis cana- 



densis. 



(ft) Morphine group, including Morphine, Apomorphine, 



Thebaine, and Codeine. 

 (c) Berberine group, including Berberine and Corydalis 



Alkaloids. 



The constitutional formulae for alkaloids of this group are 

 for the most part exceedingly complex, and it will suffice here 

 merely to show the skeleton formulae of a member of each 

 group : 



Papaverine Morphine f Berberine 



In addition to the alkaloids mentioned above, there are 

 a very large number which cannot as yet be classified, since 



* Perkin and Robinson: " J. Chem. Soc., Lond.," 1910, 97, 305. 

 fThis formula is subject to revision. 



