MARCEL NENCKI, 1847— 1901 521 



From skatolaminoacetic acid. 



/C(CH 3 ) 



^C • CH, • C0 2 H + NH, 



S H/ y>C ■ CH(NH,) • CO..H + H 2 = C 6 H 4 ^ ^C 



Skatol acetic acid. 



/ C(CH 3 ) /C(CH 3 ) 



C 6 H 4 < \C • CH, • CCLH + 3 = C 6 H 4 <^ \c ■ CO,H + CO, + H,0 



X NH N NH 



C(CH 3 ) /C(CH 3 ) 



C S H 4 < >C • CO,H = C 6 H 4 < \CH + C0 2 



X NH X NH 



Skatol. 



,C(CH 3 ) .CH 



C 6 H/ ^>CH + 3 = C 6 H 4 < ^)>CH + CO, + HA 



^NH X NH 



Indol 



At the time this scheme of reactions was published (1889) 

 all the above degradation products (or bodies with the same 

 empirical formulae) had been obtained by either Salkowski or 

 Nencki and their pupils, with the exception of the skatolamino- 

 acetic acid. A body of this empirical formula was finally 

 isolated by Hopkins and Coles in 1900, who thereby proved 

 the correctness of Nencki's speculations as to its probable exist- 

 ence as a protein hydrolysis product. It is the substance which 

 gives the so-called tryptophane reaction, although it has not, 

 as Ellinger has recently shown, the exact constitutional formula 

 assigned to it by Nencki, for the body it yields on oxidation is 

 not skatol carbonic acid, but indol acetic acid — i.e. it contains no 

 methyl group. 



The important bearing of Nencki's work on the chemical 

 dynamics of putrefaction on the general development of protein 

 chemistry will be readily perceived from the above short 

 summary. 



Nor was the biological aspect of the question neglected 

 by Nencki. It was important to determine what part bacterial 

 putrefaction played in the general economy of putrefaction. 

 Do bacteria play any necessary role in the alimentary tract 

 of the higher organisms, in causing the degradation of ingested 

 proteins ? A unique opportunity for investigating this question 

 was offered by a case of fistula of the small intestine under 



