Skatoleacetic acid

Tryptophane was found by Hopkins and Cole to have the empirical formula CnHijN Oz and to yield large amounts of indole and skatole when heated, and when subjected to putrefaction by bacteria the above-mentioned four products resulted. As under anaerobic conditions a large yield of skatoleacetic acid was obtained, and as skatole was the principal product when it was fused with potash, Hopkins and Cole regarded their substance as skatoleaminoacetic acid rather than the isomeric indoleaminopropionic acid. 

The indolepropionic acid obtained by hydrolysis was identical with Nencki s skatoleacetic acid, and tryptophane was therefore either... 

The constitution of indole and skatole had been proved by synthesis, but that of the other two compounds had not been determined, and Nencki s formulae for them were accepted. Investigations by Ellinger and Gentzen in 1903, who found that in the large intestine indole was formed in large amounts from tryptophane, but skatole only in small amounts, and that skatole only gave traces of indole under the same conditions led Ellinger to doubt the accuracy of Nencki s formulae for skatoleacetic and skatolecarboxylic acids, more especially as Wislicenus and Arnold s skatolecarboxylic acid, which was synthesised from pro-pionyl formic acid phenylhydrazone had the formula... 

---