Urobilin and Urobilinogen 



LOUIS BAUMAN 



NEW YORK 



Chemistry 



In 1868 Jaffe first described a reddish substance which he found in 

 human and canine bile and which resembled one of the urinary pigments. 

 Both absorbed certain rays between the B and F lines of the spectrum and 

 both fluoresced in the presence of zinc salts. Jaffe named the compound 

 urobilin. It is interesting to note that even at that time he was aware 

 that the pigment was not, preformed, but resulted from the oxidation of a 

 chromogen, which is now known as urobilinogen (LeNobel). 



Urobilinogen has the empirical formula, C :53 II 42 O 6 N" 4 . Fischer and 

 Boese showed that it contained 4 pyrole nuclei and that its structural 

 formula closely resembled that of bilirubin. 



Bilirubin. 

 H 2 C=HC C C CH 3 CH 3 -C C CH=CH] 2 



II II I! II 



CO C C OH 



/\ /\ /\ / 



/ NH \ / NH 



O C=C 



\ NH / \ KE 



\X \/ \/ \ 



HO C C C C CH 3 



COOH-CH 2 -CH 2 -C C-CH, CH 3 -C G-CII 2 CH 2 COOH. 



Urobilinogen. 

 CH 3 -CH 2 -C C-CH 3 CH 3 -C C-CH 2 CH 3 



HC C C C-OH 



\ /\ /\ / 



Nil \ / NH 



r\_ _r\ 



NH / \ NH 



/ \X \/ \ 



HO-C C C C-CH 3 



I! II II II 



COOH-CH 2 -CH,-C C-CH 3 CH 3 -0 C-CH 2 CH 2 COOH. 



163 



