ORNITHINE, LYSINE. 159 



AgN0 3 (the more readily soluble) and CeHuN^.AgNOs + ^H^O (the 

 mo re difficultly soluble), and its compound with picrolonic acid (STEUDEL 1 ). 

 Arginine is dextrorotatory. In 9-10 per cent solution in the presence 

 of 1 mol. HC1 and at 20 C., it has a specific rotation () D = + 10.7. 

 The arginine obtained by KUTSCHER in the tryptic digestion of fibrin 

 was racemic arginine. KUTSCHER has prepared this racemic arginine 

 from d-arginine, and RIESSER 2 has obtained /-arginine by splitting 

 racemic arginine with arginase. On oxidation with permanganate 

 it splits off guanidine, which can be precipitated with sodium picrate. 

 ORGLMEISTER 3 bases his method for the quantitative estimation of argi- 

 nine in mixtures obtained by hydrolysis upon this fact. 



CH 2 .(NH 2 ) 



//TTT \ 



Ornithine (a-^-diamino valeric acid), C 5 H 12 N 2 O 2 = ATT/ATTT \ 



CH (NH 2 ) , is not a primary 



COOH 



cleavage product of proteins, but is formed from arginine on boiling with baryta- 

 water. JAFFE,* who first discovered this body, obtained it as a cleavage product 

 from ornithuric acid, which is found in the urine of hens fed with benzoic acid. 

 The ornithine which E. FISCHER and recently SORENSEN 5 have prepared syn- 

 thetically yields, as shown by ELLINGER, putresdine (tetramethylenediamine) , 

 C 4 H 8 (NH 2 ) 2 , on putrefaction. A. LOEWY and NEUBERG 6 have shown that 

 ornithine is split into putrescine and CO 2 in the organism of cystinuria patients. 



Ornithine is a non -crystalline substance which dissolves in water, giving an 

 alkaline reaction, and yields several crystalline salts. It is precipitated by 

 phosphotungstic acid and several metallic salts, but not by silver nitrate and 

 baryta- water (differing from arginine) . Ornithine hydrochloride is dextrorotatory ; 

 the synthetically prepared one is inactive. On shaking ornithine with benzoyl 

 chloride and caustic soda it is converted into dibenzoylornithine (ornithuric acid). 

 On splitting artificially prepared racemic ornithuric acid SORENSEN has shown 

 that the naturally occurring ornithuric acid is identical with the dextrorotatory 

 a- d-dibenzoyldiamino valeric acid. 



Diaminoacetic acid, C 2 H 6 N 2 O 2 = CH (NH 2 ) 2 COOH was obtained by DRECHSEL 7 

 as a cleavage product of casein by boiling with tin and hydrochloric acid. It 

 crystallizes in prisms and gives a monobenzoyl compound which is not very soluble 

 in cold water and is nearly insoluble in alcohol, and can be used in the isolation 

 of the acid. 



CH 2 (NH 2 ) 



/PTT \ 



Lysine (a-e-diaminocaproic acid), C 6 H 14 N2O2= , was first 



CH(NH2) 



COOH 



1 Zeitschr. f. physiol. Chem., 37 and 44. 



2 Kutscher, Zeitschr. f. physiol. Chem., 28 and 32; Riesser, ibid., 49. 



3 Hofmeister's Beitrage, 7. 



4 Ber. d. d. chem. Gesellsch., 10 and 11. 



5 Fischer, ibid., 34; Sorensen, Zeitschr. f. pyhsiol. Chem., 44. 



6 Ellinger, Zeitschr. f. physiol. Chem., 29; Loewy and Neuberg, ibid., 43. 



7 Ber. d. sachs. Ges. d. Wissensch., 44. 



