478 FATE OF BODY-FOREIGN SUBSTANCES 



According to L. Lewin 64 the poisonous condensation 

 products of acetone, mesityl oxide and phorone, in the body 

 enter into combination with sulphhydryl and are excreted in 

 the urine as thioketones. 



Conjugation with Glycocoll and Ornithin. The conjuga- 

 tion of benzoic acid and its homologues with glycocoll will not 

 be dealt with here any further, as hippuric acid has already 

 been considered. It is well known that in the economy all 

 substances which are catabolized to benzoic acid lend them- 

 selves to synthesis of hippuric acid. A number of related 

 acids, too, as oxy-, nitro-, halogen-benzoic acids, toluic acid, 



phenylacetic acid, and too pyromucic acid, HC\^/C.COOH, 



O 



unite with glycocoll according to the equation : B.COOH + 

 NH 2 .CH 2 .COOH = E.CO - NH.CH 2 .COOH + H 2 0. In the 

 economy of birds benzoic acid (as discovered by Jaffe), in- 

 stead of uniting with glycocoll, combines with another pro- 

 tein derivative, ornithin (Vol. I of this series, p. 10, Chem- 

 istry of the Tissues) to form ornithuric acid : 



OBNITHIN ORNITHURIC ACID 



CH 2 .NH 2 CH 2 .NH (CO.CeH 5 ) 



CH a CH 2 



I COOH.CflHs I 



CH 2 + - > CH 2 



I COOH.CoHs 

 CH.NH 2 CH.NH. (CO.C 6 H 6 ) 



COOH COOH. 



In the avian economy pyromucic acid and phenylacetic 

 acid, C 6 H 5 - CH 2 .COOH, may also enter into an analogous 

 synthesis. 65 



Uraminoacids. There are quite a large number of state- 

 ments in literature that aminoacids in the intermediate 



"L. Lewin (Berlin), Arch. f. exper. Pathol., 56, 346, 1907. 

 "G. Totani, J. Yoshikawa (Kyoto), Zeitschr. f. physiol. Chem., 68, 75, 

 1910. 



