X] 



THE PLANT BASES 



159 



Pyridine 



Pyrrole 



\m/ 



Tropane 



Quinoline 



J 



Pyrimidine 



\7 



Iminazole 



1. The pyridine alkaloids. 



These are, as the name implies, derivatives of pyridine. (Pyridine 

 is a colourless liquid which boils at 115° C. It is a strong base and 

 forms salts with acids.) 



CH 



CH CH 



II I 



CH CH 



\/- 

 N 



Pyridine 



The more important members of this group are: arecoline, coniine, 

 nicotine, piperine and trigonelline. 



Arecoline occurs in the " Betel Nut " which is the fruit of the Areca 

 Palm {Areca Catechu). 



Coniine occurs in all parts of the Hemlock (Conium macidatum), 

 but more especially in the seed. 



Nicotine occurs in the leaves of the Tobacco plant {Nicotiana 

 Tabacum). It is a colourless oily liquid which is intensely poisonous. 

 Its constitution may be represented as : 



CH CH„— CHo 



^\ I I 



CH C— CH CHo 



I II \/ " 



CH CH N 



\/ I 



N CH., 



It is readily soluble in water and organic solvents. 



