THE MONO-AMINO-ACIDS. 85 



ing acids from which they are derived. Glycocoll is thus transformed 

 into acetic acid, leucin into capronic acid, asparaginic acid into suo- 

 cinic acid, glutaminic acid into glutaric acid, tyrosin into para-oxy- 

 phenyl-propionic acid (hydroparacumaric acid), etc., as shown by 

 the equations : 



CH 2 (NH 2 ).COOH + 2H = CH 3 .COOH + NH 3 

 Glycocoll. Acetic acid. 



CH /COOH 



+ 2H = CH 2 .CH 2 .< -f NH 3 



H \COOH 



Asparaginic acid. Succinic acid. 



/OH /OH 



C 6 H/ + 2H = C 6 H / -f NH 3 



\CH 2 .CH(NH 2 ).COOH \CH 2 .CH 2 .COOH 



Tyrosin. Para-oxy-phenyl-propionic 



acid. 



On oxidation these are further changed into the acids standing 

 next in order in the downward scale. Acetic acid thus gives rise to 

 the formation of formic acid, succinic acid to malonic acid, para-oxy- 

 phenyl-propionic acid to para-oxy-phenyl-acetic acid, etc., as shown 

 by the equations : 



CH 3 .COOH -f 3O = H.COOH + H 2 O + CO 2 

 Acetic acid. Formic acid. 



/COOH /COOH 



CH 2 .CH 2 .< + 3O = CH 2 < -f H 2 O + CX). 



\COOH \COOH 



Succinic acid. Malonic acid. 



/OH /OH 



C 6 H 4 / + 30 = C 6 H 4 < + H 2 '+ C0 3 



\CH 2 .CH 2 .CX30H \CH 2 .CX)OH 



Para-oxy-phenyl-propionic Para-oxy-phenyl-acetic 



acid. acid. 



Through a splitting off of carbon dioxide para-oxy-phenyl-acetic 

 acid then further gives rise to paracresol, from which phenol is 

 finally obtained on oxidation : 



/OH /OH 



C 6 H/ = C 6 H/ + CO, 



\CH 2 .COOH \CH S 



Paracresol. 

 /OH 



C 6 H/ + 3O = C 6 H 5 .OH -f CO 2 + H,O 

 X CH 3 Phenol. 



In the animal body paracresol and phenol, which are formed from 

 tyrosin during the process of intestinal putrefaction, then combine 

 with sulphuric acid, and are eliminated through the urine in the 

 form of their potassium salts : 



/OH /OH /O.HS0 3 



/OH 

 C 6 H 5 .OH +S0 2 / = C 6 H 5 .O.HS0 3 + H 2 O. 



