THE ORGANIC NON-NITROGENOUS ACIDS. 97 



Of the non-hydroxylated aromatic acids, two are found in the 

 animal body, and, like the hydroxylated compounds, originate during 

 the process of albuminous putrefaction. These are phenyl-propionic 

 acid (hydrocinnamic acid) and phenyl-acetic acid. They are rep- 

 resented by the formulae : 



C 6 H 5 CH 2 .CH 2 .COOH == phenyl-propionic acid 

 C 6 H 5 .CH 2 COOH = phenyl-acetic acid. 



By combining with glycocoll they give rise to the formation of 

 hippuric acid and phenaceturic acid, respectively. In the first 

 instance, however, benzoic acid is apparently first formed, which 

 then unites with glycocoll, as shown in the equations below : 



(1) C 6 H 5 .CH 2 .CH,.COOH + 6O = C 6 H 5 .COOH + 2CO 2 + 2H 2 O 



Phenyl-propionic Benzoic acid, 



acid. 



(2) C 6 H 5 .COOH + CH 2 (NH 2 ).COOH = C 6 H 5 .CO.CH 2 .NH.COOH -f*H 2 O 

 Benzoic acid. " Glycocoll. Hippuric acid. 



and 



C 6 H 5 .CH 2 .COOH + CH 2 (NH 2 ).COOH == C 6 H 5 .CH 2 .CO.NH.CH 3 .COOH + H 2 O 

 Phenyl-acetic Phenaceturic acid, 



acid. 



