PTOMAINES 371 



NCH3 



CHj CH . CH2 . CO . CH3 + 2CO2 



I I 



CH2 — CH2 



IV. 



Compound III. may also be the progenitor of nicotine by 

 further condensation with formaldehyde and ammonia. Simi- 

 larly, by the application of simple reactions, e.g. aldol con- 

 densations, oxidation, or dehydration, Robinson is able to 

 account for the formation of such complex alkaloids as the 

 pelletierines, sparteine, and the opium alkaloids belonging to 

 the piperidine, quinuchdene, and isoquinoline groups respec- 

 tively. 



PTOMAINES. 



Associated with the simplest form of plant life, namely, 

 bacteria, a number of different basic substances are found, 

 some of very simple constitution, such as methylamine, 

 CH3NH2, dimethylamine, (CH3)2NH, trimethylamine, (CH3)3N 

 putrescine, NH2(CH2)4NH2, cadaverine, NH2(CH2)5NH2, and 

 others rather more complex, such as choline, muscarine, 

 neurine, collidine, etc., and some of unknown constitution, 

 such as mydaleine and sepsine. These substances are known 

 as ptomaines,* from the fact that they are usually associated 

 with decomposing flesh ; some of them, such as putrescine and 

 cadaverine, are practically non-poisonous, while others are 

 highly toxic, producing increased salivation, diarrhoea, vomit- 

 ing, etc. 



On the whole, however, it is at least doubtful whether the 

 manifestations of ptomaine poisoning are to be attributed 

 entirely to these substances ; it would seem more likely that 

 they were largely due to bacterial toxins, a class of substance 

 related to the albumoses, which have the power of inducing 

 the formation in the blood of antibodies, or, as they are 

 better called, anti-toxins. Similar toxins or toxalbumins also 

 occur in certain of the higher plants, as, for example, abrin, 

 obtained from Abrus precatorius, and ricin, which occurs in 

 Ricinus. 



* From the Greek word wTOj/xa, meaning corpse. 



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