40 CHEMISTRY OF THE PROTEIDS CHAP. 



NH 



c_NH CH 2 CH 2 CH 2 CH COOH. 



" ^2/ 



Therefore by a simple splitting both urea and ornithin (see below) 

 may be derived from it. Thus boiling with baryta water gives rise 

 to urea, because arginin belongs to the same class of bodies as does 

 creatinin or methyl-guanidin-acetic acid. 



; N(CH 3 )CH 2 COOH = 2 CO + NH(CH 3 )CH 2 COOH 



Creatin = urea + sarcosin. 



On the other hand, oxidation with barium permanganate l leads to 

 the production of guanidin-butyric acid, and subsequently to that of 

 guanidine, imido-urea, or carbamidine, NH : C(NH 2 ) 2 , and succinic acid, 

 COOH . CH 2 . CH 2 . COOH. The formation of urea from arginin, or, 

 as he thought, lysatinin, is first mentioned by Drechsel, and later 

 Kossel 2 laid stress on the different biological significance of that urea 

 which is preformed in arginin, and of that which is formed synthetic- 

 ally. That arginin gives rise to urea during ordinary metabolism 

 seems to be proved by the discovery of arginase by Kossel and Dakin, 

 see p. 111. 



Ornithin, CH 2 (NH 2 ) . CH 2 . CH 2 . CH(NH 2 ) . COOH, or -S-di- 

 amino-valerianic acid, is of great importance, because E. Schulze and 

 E. Winterstein 3 have shown that arginin may be regarded as a union 

 of guariidin (see above) with ornithin. This latter has been found in 

 the urine of birds as dibenzoyl-ornithin or ornithuric acid by Jaffa, 4 

 and has been synthetically prepared by E. Fischer. 5 



A full description of arginin, a number of its salts, and derivatives, 

 is given by Gulewitsch ; 6 Lawrow 7 describes a benzoyl derivative, and 

 Herzog 8 the phenylhydantoin of ornithin. Arginin forms a very 

 slightly soluble salt with picrolonic acid, 9 which may be employed for 

 its isolation. Arginin is dextro-rotatory. In strong hydrochloric acid 



Gulewitsch found 



a D = +21-25. 



1 E. Benech and F. Kutscher, Zeitschr. f. physiol. Chem. 32. 278 (1901); F. 

 Kutscher, find. 32. 413 (1901) ; and especially F. Kutscher and J. Otori, ibid. 43. 

 93 (1984). 2 A. Kossel, Ber. d. deutsch. chem. Ges. 34. III. 3214 (1901). 



3 E. Schulze and E. Winterstein, ibid. 3O. III. 2879 (1897) ; Zeitschr. f. physiol. 

 Chem. 26. 1 (1898). 



4 M. Jaffe, Bericht d. deutsch. chem. Ges. 10. II. 1925 (1877), 11. I. 406 (1878). 



5 E. Fischer, ibid. 34. I. 454 (1901). 



6 W. Gulewitsch, Zeitschr. f. physiol. Chem. 27. 178 and 368 (1899). 



7 D. Lawrow, ibid. 28. 585 (1899). 8 R. 0. Herzog, ibid. 34. 525 (1902). 

 9 H. Steudel, ibid. 37. 219 (1902). 



