CHAPTER X. 



PUTREFACTION PRODUCTS. 



THE putrefactive processes in the intestine are the result of the 

 action of bacteria upon the protein material present. This bac- 

 terial action which is the combined effort of many forms of micro- 

 organisms is confined almost exclusively to the large intestine. 

 Some of the products of the putrefaction of proteins are identical 

 with those formed in tryptic digestion, although the decomposition 

 of the protein material is much more extensive when subjected 

 to putrefaction. Some of the more important of the putrefaction 

 products are the following : Indole, skatole, paracresol, phenol, para- 

 oxyphenylpropionic acid, para-oxyphenylacetic acid, volatile fatty 

 acids, hydrogen sulphide, methane, methyl mercaptan, hydrogen, 

 and carbon dioxide, beside proteoses, peptones, ammonia and amino 

 acids. Of these the indole, skatole, phenol and paracresol appear 

 in part in the urine as ethereal sulphuric acids, whereas the oxyacids 

 mentioned pass unchanged into the urine. The potassium indoxyl 

 sulphate (page 279) content of the urine is a rough indicator of the 

 extent of the putrefaction within the intestine. 



The portion of the indole which is excreted in the urine is first 

 subjected to a series of changes within the organism and is sub- 

 sequently eliminated as indican. These changes may be represented 

 thus: 



NH 



Indole. Indoxyl. 



N __C(OH) /\__C(0-S0 3 H) 



' || +H 2 S0 4 = | | || + H 2 



\/\/CH \/\/CH 

 NH NH 



Indoxyl. Indoxyl sulphuric acid. 



In the presence of potassium salts the indoxyl sulphuric acid is 

 then transformed into indoxyl potassium sulphate (or indican), 



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