BACTERIAL METABOLISM WITHIX THE BODY 685 



takes place chiefly in the small intestine. A change of diet, restricting 

 protein and furnishing a large part of the caloric requirement above that 

 associated with a reasonable level of nitrogen equilibrium, by carbohy- 

 drate and fat, usually will lead to a reduction of protein putrefaction 

 through the sparing action of utilizable carbohydrate for protein in the 

 metabolism of the intestinal bacteria. 



4. The Effects of Utilizable Carbohydrate upon the 

 Formation of Phenols, Indol and Amins 



Simple decarboxylization of aromatic amino acids gives rise to amins, 

 some of which are of significance from/their physiological action. Thus, 

 ornithin, NH 2 .CH 2 .CH 2 .CH 2 .CH^H 2 .COOH, is changed by mixtures of 

 bacteria acting upon protein into putrescin or tetramethylenediamin, 



NH 2 .CH 2 .CH 2 .CH. 2 CHIs r H 2 c6OH -^ 



CH 2 CH 2 CH 2 CH, + CO 2 



and lysin similarly is decarboxylized to cadaverin : 



]STH 2 CH 2 .CH 2 .CH 2 .CH 2 .CHNII 2 .COOH-> 



CH 2 CHoCH 2 CII 2 CII 2 + C0 2 , 



_ 



or pentamethylenediamin. 



Putrescin and cadaverin were about the first of the group of sub- 

 stances, frequently called ptomains, to be isolated and identified. It is 

 probable that sepsin (Fraenkel) also belongs to this class of diamins. 

 The clinical significance of cadaverin and putrescin is not clear. These 

 substances have been frequently detected and occasionally isolated from 

 cases of cystinurea (Spiegel). The information available at present is 

 insufficient to explain the relationship, however, if, indeed, any exists. 



Sepsin is said by some to be a capillary poison (Barger). 



Tyrosin is changed by the loss of the carboxyl group to tyramin 

 or paraoxyphenyl ethylamin. 



OH OH 



+ C0 

 CH.CH]S T H.COOH + II CH 2 .CH 2 2iTH 2 . 



