ALKALOIDS 



61 



Alkaloid. 

 Aconitine 



Atropine 



Cephaeline 



Cocaine . 

 Coniine . 

 Hyoscyamine 



Morphine 

 Nicotine . 



Quinine 

 Strychnine 



Action. 

 Poisonous (used as 



an antipyretic) . 

 Poisonous (various 



medicinal uses) . 



Emetic (active 

 principle of ipe- 

 cacuanha) . 



Local anaesthetic. 



Source, etc. 



Leaves, root, etc., of Monkshood 

 (A conitum napellus] . 



All organs of Deadly Nightshade or 

 Belladonna (Atropa belladonna], 

 seeds especially of Thornapple (Da- 

 tura stramonium, Fig. 26) (Solan- 

 aceae) . 



Root of Psychotria ipecacuanha (Fam . 

 Rubiaceae, Brazil). 



Leaves of Erythroxylon coca (Fam. 



Linaceae, Bolivia and Peru). 

 Poisonous (para- Seeds of Hemlock (Conium macula- 



lytic effect) . turn, Umbelliferae). 

 Poisonous (seda- Henbane (Hyoscyamus niger], A tropa 

 tive) . belladonna, Datura stramonium 



(Fig. 26). 

 Narcotic (active Young fruits of Opium Poppy (Pap- 



principle of opium) aver somniferum) . 

 Poisonous . Leaves of Tobacco (Nicbtiana taba- 



cum, Solanaceae). 



Febrifuge . . Bark of Cinchona spp. (Rubiaceae). 



Poisonous, heart Seeds of Strychnos nux-vomica (Fam. 

 and respiratory Loganiaceae) . 

 stimulant. 



The alkaloids as a whole are not characterised by any very 

 specific reactions, but they are precipitated from solution by 

 many different reagents (e.g. iodine in potassium iodide, tannic 

 acid) . They give very marked colour-reactions with various 

 substances ; thus a section of the rhizome of the Monkshood 

 treated with a little 50 per cent, sulphuric acid shows a bright 

 red colouration in the parenchyma adjoining the vascular strands, 

 as a result of the presence of aconitine. 



The ptomaines, which are basic in character, are compounds 

 produced during the decomposition of flesh, etc., by the 

 agency of Moulds and Bacteria, but it is not altogether certain 

 that the effects of so-called "ptomaine-poisoning" are solely 

 due to these substances. Such stimulants as the caffeine of 

 tea-leaves, coffee-beans, cocoa-beans, and Kola (Cola acuminata), 

 and the theobromine present in the Cocoa, are derivatives of 

 purine and very similar to the alkaloids. 



The characteristic and often pleasing odour of many Labiatse 

 (e.g. Lavender, Mint, etc.) and Umbelliferae (e.g. Fennel), as well 



