86 THE CHEMICAL CONSTITUTION OF THE PROTEINS 



X OH 



CH 3 . CO . COOH + NH 8 - CH 3 . CO . COONH 4 -H> CH S . C^-COOH 



X NH 2 



This compound then reacts with pyruvic acid : 



OH 



OH CH, C COOH 



1 JH 



CH, C COOH + CH, . CO . COOH = 



NH a CH 3 _C_COOH 



OH 



and the compound thus formed loses carbon dioxide giving the com- 



pound. 



OH 



Jn, 



i 



CH 3 C COOH 



OH 

 which possesses the group, 



CHOH NH-COH COOH. 

 By intramolecular rearrangement and loss of water this becomes 



NH CH COOH 



I 



The above compound by rearrangement and loss of water is thus 



converted into acetylalanine : 



CH 3 .C=0 



NH 



CH 3 . C . COOH 

 H 



Fischer and Groh, in 1911, showed that some amino acids were 

 most readily prepared by the reduction of the phenylhydrazone of the 

 corresponding ketonic acid with aluminium amalgam. Though it is not 

 the most advantageous method for the preparation of alanine, this 

 compound is easily obtained by the reduction of the phenylhydrazone 

 of pyruvic acid : 



CH 3 CH 3 CH 3 



CO -> C:N.NH.C 6 H 5 -> CH . NH 2 + H 2 N . C 6 H 5 



COOH COOH COOH 



