MATERIAL TRANSFORMATIONS IN THE PLANT 1 63 



d-Valin (a-amino-isovaleric acid), J^ 3 >CHCHNH 2 COOH. 



CH3/ 



/-Leucin (a-amino-isocaproic acid, a-amino-isobutyl-acetic acid), 



^2 3 ^>CHCH 2 CHNH,COOH. 



C-T13/ 



d-Isoleucin (/3-methyl-/3-ethyl-a:-amino-propionic acid), 



i^ 3 ^>CHCHNH 2 COOH. 

 L2H5/ 



/-Aspartic acid (a-amino-succinic acid), COOHCH 2 CHNH 2 COOH. 



d-Glutamic acid (a-amino-glutaric acid), COOHCH 2 CH 2 CHNH 2 COOH. 



B. Diamino acids 



Lysin (a-e-diamino-caproic acid), NH 2 CH 2 CH 2 CH 2 CH 2 CHNH 2 COOH. 



d-arginin (5-guanidin-a-amino-valeric acid), 



HN = C /NH 2 



\NHCH 2 CH 2 CH 2 CHNH 2 COOH. 



Cystin (a-diamino-/3-dithio-dilactylic acid), 



CH 2 CHNH 2 COOH— S— S— CH 2 CHNH 2 COOH. 



Aromatic Compounds 



/-Phenyl alanin (/3-phenyl-a-amino-propionic acid), 



C 6 H 5 CH 2 CHNH 2 COOH. 



/-Tyrosin (/3-para-hydroxyphenyl-a-amino-propionic acid), 



HOC 6 H 4 CH 2 CHNH 2 COOH. 



3. Heterocyclic Compounds, Derivatives op Imidazol, Pyrrol and Indol 



/-Histidin (/3-imidazol-a-amino-propionic acid), 

 CH = C— CH 2 CHNH 2 COOH 



N NH 



\/ 

 CH 



/-Prolin (a-pyrrolidin-carboxylic acid), 

 CH 2 — CH 2 



CH 2 CHCOOH 



NH 



/-Hydroxyprolin (hydroxy-a-pyrrolidin-carboxylic acid), 

 /-Tryptophan (jS-indol-a-amino-propionic acid). 

 C— CH 2 CHNH 2 COOH 



C 6 H 4 /%CH 

 NH 

 The relative amounts of the various amino acids obtained from different 

 proteins are not constant, as is evident from the following table, which shows 

 these amounts for seeds of wheat and oats. 



