122 CHEMISTRY OF THE PROTEIDS CHAP. 



C f) H 5 CO NHCH 2 CO NHCHCO NHCHCO N 3 



CH 2 CO . NH 



CH 2 CO . NHCHCO NH 

 CH 2 CO N 3 . 



On coupling this compound with two molecules of aspartic acid the 

 4-basic hippuryl-di-asparagyl-aspartic acid was obtained : 



C 6 H 6 CO NHCHgCO NHCHCO NHCHCO NHCH . COOH 



CH 2 CO.NHCH 2 .COOH 

 CH 2 CO NHCHCO. NH 



CH 2 CO . NHCHCOOH 

 CH 2 COOH. 



All the aspartic-acid-compounds give a violet colour with Fehling's 

 solution. 



Many of the compounds are characterised by separating out from 

 their solutions in a very swollen state, and even dilute solutions may 

 form so stiff a jelly that the vessel containing them may be inverted. 

 Under the microscope they appear, with the exception of hippuryl- 

 aspartic acid, as globules, without any crystalline character, i.e. as 

 colloids. 



On endeavouring to introduce the hippuryl-group into the amino- 

 group of /3-amino-a-oxypropionic acid, Curtius and Gumlich only 

 succeeded in getting hippuryl-a-oxy-/3-amino-propionic acid 



C 6 H 5 CO . NHCH 2 CO . O . (CH 2 NH 2 )COOH, 



while hippurazide and /3-amino-butyric acid yielded as usual the corre- 

 sponding hippuryl-/3-aminobutyric acid : 



C 6 H 5 CO . NHCH 2 CO . NHCH(CH 3 )CH 2 . COOH. 



By introducing the hippuric-acid-remainder into /?-phenyl-a-alanin 

 (or /3-phenyl-a-amino-propionic acid) Curtius and E. Miiller obtained 

 the hippuryl-/?-phenyl-a-alanin, 



C 6 H 5 CO . NHCH 2 CO . NH 



C 6 H 5 .CH 2 .CH.COOH. 



