BASES OF BIO-CHEMICAL INTEREST 

 DERIVED FROM THE PROTEINS 



By GEORGE BARGER, D.Sc. 



It has long been known that when albuminous substances un- 

 dergo putrefactive changes a variety of more or less poisonous 

 basic products are formed, often only in very minute propor- 

 tions ; to some of these the term Ptomaines has been applied. 

 Of late years much has been done to determine the nature of 

 these products and it is now clear that, as a rule, the bases are 

 closely related to the simple amino- and imino-compounds into 

 which the proteins are resolved by hydrolysis ; about sixteen 

 such amino-acid derivatives are now well known and bases have 

 been obtained corresponding to nearly all of them, in most cases, 

 simply by withdrawing carbon dioxide from the amino-acid. 



Several of the bases are of particular interest because of 

 their physiological activity and the chapter is one of peculiar 

 importance on this account. Many of the compounds to 

 be described may be formed from any protein exposed to 

 bacterial action. It is not necessary that obvious putrefaction 

 should occur : thus some are formed during the ripening of 

 cheese or by the fermentative changes which necessarily attend 

 the preparation of certain kinds of food. The production of 

 simple, physiologically active bases from proteins, however, is 

 not the outcome of bacterial action alone : probably they are 

 also formed, by natural processes, in the tissues of animals and 

 it is in some such way that we can picture the production 

 taking place of hormones like secretin, which not improbably 

 are of simple chemical constitution. Later on, in the section 

 dealing with the base /3-iminazolylethylamine, attention will 

 be drawn to the close similarity in the action of this base and 

 that of the toxic substance formed in an anaphylactic animal 

 as the consequence of the injection of an innocuous protein. 



The general conclusion which can be drawn at present is 

 that the physiologically active substances in the animal organism 

 are simpler than they were at one time supposed to be. We 



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