THE CHEMISTRY OF ALBUMINS 201 



Ptomaines 



These bodies are products of putrefactive decompositiou 

 of albiunin and are mostly strong bases ; they can be obtained 

 by splitting off COg from amino acids. Thus leucin gives rise 

 in this way to pentamethylene-diamine or cadaverin according 

 to the following equation : — 



CH2NH2- (CHj),- CHNH2COOH 



= CH2NH2-(CH2)3-CH2NH2 + C02 



while argenin gives rise to putrescin, cyanamide being formed 

 at the same time : — 



NH,C(NH)NH- CH2 - (CH2)2CHNH2-COOH 



= NH2-CN + CO2 + NH2CH3-(CH2)2-CH2NH2 



Oyanamide Putrescin 



Carbohydrates 



These occur among the decomposition products of certain 

 albumins in the form of amino derivatives of which 

 glucosamin, CH^OHCHOHCHOHCHOHCHNHaCHO, is a 

 characteristic example. 



Synthesis of Disintegration Products.— We are now in a 



position to understand something of the significance of the 

 syntheses of the complicated bodies known as polypeptides, 

 from the starting point of the disintegration products which 

 have just been described. It would lead too far to attempt to 

 give these in any detail, but the simplest case will suf&ce to 

 indicate the principle on which more complex substances may 

 be built up. Glycocoll or glycin may be taken as a starting 

 point. 



The ethyl ester is first prepared ; on standing, condensation 



