PROTEID PUTREFACTION 469 



A. PROTEID PUTREFACTION 



(1) SUBSTANCES DERIVED FROM THE AROMATIC RADICALS OF 

 THE PROTEID MOLECULE 



In the proteid molecule are contained the following ammo- 

 acids with an aromatic nucleus : 



Tyrosin, HO/ \CH 2 CH COOH, 



Phenylalanin, /~^>CH 2 CH COOH, 



Tryptophan, 1 \_/~ C ~~ CHz ~~ CH " COOH 



\ >CH 



V 



H 



/COOH 

 or, < >-C-CH-CH 2 -NH r 



N 

 H 



In the intestinal contents have been found a number of sub- 

 stances that are undoubtedly derived from these aromatic radicals. 

 They are (1) phenol, 



OH, 



which is formed in small quantities, presumably from tyrosin, 

 as also is the closely relate^ (2) paracresol, 



HO/ NcH 3 , 

 and also (3) para-oxyphenyl acetic acid, 



HO^~^>CH 2 COOH, 

 and (4) para-oxyphenyl-propionic acid, 



HO\ )CH 2 CH 2 COOH. 



1 The correct structural formula for tryptophan has not yet been finally 

 determined, but the two formulae given above are as proposed by Ellinger (Ber. 

 deut. Chem. Gesellsch., 1904 (37), 1801). The formula originally proposed by 

 Hopkins and Cole cannot be considered as correct in view of Ellinger'a 

 observations. For a full discussion of this subject see Mann's "Chemistry of 

 the Proteids," p. 51. 



