THE ORGANIC NON-NITROGENOUS DERIVATIVES. 93 



X)H 



Tyrosin (para-oxy-phenyl-amino-propionic acid) = 



\CH 2 .CH(NH 2 ).COOH 



C: 

 2 .CH 2 .COOH 



/OH 

 Para-oxy-phenyl-acetic acid = C 6 H 4 <^ 



X CH 2 .COOH 



/OH 

 Para-oxy-phenyl-lactic acid = C 6 H 4 \ 



\CH 2 .CH.OH.COOH 



/OH 



Para-oxy-phenyl-glycolic acid = C 6 H 4 < 



X CH.OH.COOH 



On decomposition these acids yield phenol or cresol, water, and 

 carbon dioxide, as shown by the equations : 



/OH /OH 



+ 30 = C 6 H 4 



.COOH 



(1) C 6 H 4 + 30 = C 6 H 4 + 00 2 + H 2 0. 



\CH 2 .CH 2 . COOH \CH 2 . 



/OH /OH 



(2) C 6 H 4 < + 3O = C 6 H 4 < -f CO 2 + H 3 O 



X CH 2 .COOH \COOH 



Para-oxy- 

 benzoic acid. 



/OH 



(3) C 6 H 4 < = C 6 H 5 .OH + (X) 2 



\COOH Phenol. 



or 



/OH /OH 



(1) C 6 H 4 = C 6 H 4 + C0 2 



\CH 2 .COOH \CH 3 



Paracresol. 



/OH 



(2) C 6 H 4 < + 30 - C 6 H 5 .OH + CO 2 + H 2 O 



\CH 3 Phenol. 



From phenol the two dioxybenzols pyrocatechin and hydro- 

 quinon can then result, and appear in the urine together with 

 phenol as conjugate sulphates or glucuronates. 



OH(1) 

 C 6 H 5 .OH + O = C 6 H / 



\OH(2) or (4). 



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. 



