TRIGLYCERIDES AND FATTY ACIDS 



73 







M 



CfiHs-C— jOH + H;NH-CH2-C00H 



Benzoic Glycine 



acid 



O H 



-> CfiHb-C— N-CH2-C00H + H2O 

 Hippuric acid 



The Detoxication of Benzoic Acid with Glycine 



It is now known that not only may glycine be used for the detoxication 

 of benzoic acid, but glucuronic acid may also serve as a second line of de- 

 fense, as follows : 



O 



h 



HC— OH 

 HC— OH 

 CeHsCOOH + HOCH 

 HCOH 

 Hi— 



HC— O- 



•CrHb 



li- 



HC— OH 



-^ HOCH 



.i 



O + H2O 



HCOH 



Benzoic 

 acid 



COOH 



Glucuronic 



acid 



HC 



OOH 

 Benzoyl 

 glucuronide 



The Detoxication of Benzoic Acid with Glucuronic Acid 



It was likewise demonstrated by Salkowski and Salkowski,^ in 1879, and 

 later by Knoop, that phenylacetic acid is not oxidized, but that it is also 

 coupled with glycine to yield phenaceturic acid, which is excreted in the 

 urine. 



O 



CeHsCHo-qOH + H1NHCH2COOH 



Phenylacetic 

 acid 



Glycine 



O H 



CeHs ■ CH2 • C— N • CH2 • COOH + H2O 

 Phenaceturic acid 



The Detoxication of Phenylacetic Acid with Glycine, with the Formation of Phenace- 

 turic Acid 



Thierfelder and Sherwin^ reported that, in the case of man, phenylacetic 

 acid is conjugated with glutamine to form phenacetylglutamine. 



When the phenyl-substituted fatty acids with aliphatic chains longer 

 than that of acetic acid were fed, they were oxidized either to benzoic or to 

 phenylacetic acid. This derivative was then conjugated with glycine or 

 glucuronic acid, and was subsequently excreted in the urine. Apparently 



6 E. Salkowski and H. Salkowski, Ber., IS, 653-655 (1879). 



« H. Thierfelder and C. P. Sherwin, Ber., 47, 2630-2634 (1914); Z. physiol. Chem., 

 04, 1-9 (1915). 



