CHAPTER XIII 

 PUTREFACTION PRODUCTS 



THE putrefactive processes in the intestine are the result of the 

 action of bacteria upon the protein material present. This bacterial 

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

 is confined almost exclusively to the large intestine. Some of the prod- 

 ucts 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-oxyphen- 

 ylacetic acid, volatile fatty acids, hydrogen sulphide, methane, methyl 

 mercaptan, hydrogen, and carbon dioxide, besides proteoses, peptones, 

 peptides, ammonia, and amino-acids. Basic substances such as choline, 

 neurine, putrescine and cadaverine are present under certain conditions. 

 Of the putrefaction products 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 386) 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 sub- 

 jected to a series of changes within the organism and is subsequently 

 eliminated as indican. These changes may be represented thus: 



CH C(OH) 



/\/CH \/\/CH 



NH NH 



Indole. Indoxyl. 



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) , 



C(0-S0 3 K), 



and eliminated as such in the urine. 



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