00 A. I. RIXGER 



j 



2. Tvrosiri or a-amim> para hydroxy plienyl propionic acid. 



COH 



/ \ 

 IIC Oil 



I II 



IIC CII 



\ / 



c 



CII 2 



CHXH 2 



I 

 COOH 



These ammo acids are similar to those of the monobasic mono-ammo 

 acid group, except that they are derivatives of the phenyl group. 



F. Jleteroeyclic amino acids. 



1. Prolin or a-pyrolidin carboxyiic acid. 



HoC CH 2 



"I I 

 HoC CH COOH or 



\ / 



XH 



Pyrolidin 

 radical 



2. Oxyprolin or hydroxypyrolidin carlwxylic acid. 

 HOHC CH 



! CH COOH or CIIOH 



\ / I 



XII Clio 



coon 



