732 URINE. 



C.CH 3 



Skatoxyl-sulphuric Acid, C 9 H 9 NS0 4 , C 6 H 4 <^C.O.S0 2 .OH, has not 



NH 



been positively prepared as a constituent of normal urine, but OTTO 

 has once prepared its alkali salt from diabetic urine. Perhaps skatoxyl 

 occurs in normal urine as a conjugated glucuronate (MAYER and NEU- 

 BERG *), and it is believed that the urine contains a skatol-chromogen 

 from which red and reddish-violet coloring-matters are obtained by 

 decomposition with strong acids and an oxidizing agent. 



Skatoxyl-sulphuric acid originates, if it exists in the urine, from 

 skatol, which is formed by putrefaction in the intestine, and which is 

 then conjugated with sulphuric acid after oxidation into skatoxyl. That 

 skatol introduced into the body passes partly as an ethereal-sulphuric 

 acid into the urine has been shown by BRIEGER. Indol and skatol act 

 differently, at least in dogs, indol producing a considerable amount 

 of ethereal-sulphuric acid, while skatol gives only a small quantity (Mss- 

 TER 2 ). Reports on this subject are at variance. 



The conditions for the formation of indol and skatol by the putrefaction of 

 proteins in the intestine are decidedly different, according to HERTER, as skatol 

 is produced by other putrefaction bacteria than indol. For example, bacillus coli 

 communis produces indol, but only traces of skatol, while skatol is formed by 

 certain anaerobic putrefactive bacteria. An important intermediary step in the 

 formation of skatol is the indol acetic acid (skatol carboxylic acid, according to 

 SALKOWSKI) and this can also pass into the urine and is the chromogen of the 

 urorosein, according to HERTER. 3 



The potassium salt of skatoxyl-sulphuric acid is crystalline; it dis- 

 solves in water, but with difficulty in alcohol. A watery solution becomes 

 deep violet with ferric chloride. The solution becomes red with con- 

 centrated hydrochloric acid with the separation of a red precipitate. 

 This precipitate (skatol red) is, after washing with water, insoluble in 

 ether but soluble in amyl alcohol. On distillation with zinc-dust the 

 red pigment gives a strong odor of skatol. 



Urines containing skatoxyl are colored dark red to violet by JAFFE'S 

 indican test even on the addition of hydrochloric acid alone; with nitric 

 acid they are colored cherry red, and red on warming with ferric chloride 

 and hydrochloric acid. A red coloration of the urine can also be brought 

 about by the appearance of indigo red (indirubin) and a confusion of 

 this pigment can also take place. ROSIN 4 is of the opinion that no 



1 Otto, Pfliiger's Arch., 33; Mayer and Neuberg, Zeitschr. f. physiol. Chem., 29. 

 * Brieger, Ber. d. deutsch. chem. Gesellsch., 12, and Zeitschr. f. physiol. Chem., 

 4, 414; Mester, ibid., 12. 



3 Journ. of biol. Chem., 4. 



4 Rosin, Virchow's Arch., 123. 



