CLASSIFICATION 257 



whilst nicotine contains two rings, one a pyridine ring and 

 the other a pyrrolidine ring — 



CH„ CHo 



r I " 



CH„ CH2 



\" / 



NH 

 Pyrrolidine 



such as is also found in proline (see p. 306). 



II. Pyrrolidine Alkaloids. — This is a small group, com- 

 prising as yet only three alkaloids, namely : — 



Hygrine and Kuskhygrine, from the leaves of Erythroxylon 



Coca, and 

 Stachydrine, from the tubers of Stachys tuberifera* and 



leaves of Citrus vulgaris.^ 

 The constitution of stachydrine is as follows : — 



CHa— CHa 



CO— CH CHo 



I \/ 

 O N(CH3), 



Stachydrine 



showing it to be a dimethyl betaine of pyrrolidine. 



III. Tropane Alkaloids. — The alkaloids belonging to this 

 group are derivatives of tropane — 



CH„ 



/ \ 

 CHo CH2 



I I 



CH CH 



\ / 

 NCH3 



CHa CHo 



Tropane 



which substance, as may be seen, contains both a six-mem- 

 bered piperidine ring and a five-membered pyrrolidine ring. 



The group includes alkaloids from the four Natural 

 Orders : — 



Solanaceae, e.g. Atropine, Hyoscine, Hyoscyamine. 



* Planta and Schulze : "Arch. d. Pharm.," 1893, 305; " Ber. deut. chem. 

 Gesells.," 1893, 26, 939; Schulze and Trier: " Ber. deut. chem. Gesells.," 1909, 

 42, 4654; " Zeit. physiol. Chem.," igio, 67, 59. 



t Jahns: "Ber. deut. chem. Gesells.," 1896, 29, 2065. 



;|:For an explanation of the term betaine, see p. 265. 

 17 



