96 THE NITROGENOUS DERIVATIVES OF THE ALBUMINS. 



They are probably all derivatives of tyrosin, and it has already 

 been shown (p. 89) how hydroparacumaric acid results from this on 

 reduction, and is then transformed into para-oxy-phenyl-acetic acid 

 by oxidation. 



The formula of these acids and their relation to tyrosin are seen, 

 below : 



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



H 2 .CH(NH 2 ).COOH 



/OH 



Para-oxy-phenyl-propionic acid = C 6 H/ 



\CH 2 .CH 2 .COOH 



/OH 

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



X CH 2 .COOH 



/OH 

 Para-oxy-phenyl-acetic acid = CJEL< 



\CH 2 .COOH 



/OH 

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



X 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 



(1) C 6 H 4 < + 30 = C 6 H 4 < + C0 2 -f H 2 0. 



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



OH /OH 



CH 2 .COOH 



/ 



(2) C 6 H 4 + 30 = C 6 H 4 < + C0 2 + H 2 



XX)OH 



Para-oxy- 

 benzoic acid. 

 /OH 



(3) C 6 H 4 < = C 6 H 5 .OH + C0 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 



X 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. 



C 6 H 5 .OH + = C 6 H 4 



011(2) or (4). 



