BASES DERIVED FROM THE PROTEINS 223 



£JJ S >CH . CH 2 CH(NH 2 ) . COOH -> £h;>CH ■ CHi CH < 0H 

 ^»>CH.CH(NH 2 ).COOH -> ^ 3 >CH . CH 2 OH 



The succinic acid in wine is derived from aspartic acid : 



CE, .COOH CH.,.COOH 



I "> I 



CH(NH,).COOH CH 2 .COOH 



There are, however, putrefactive bacteria which — if grown 

 under certain conditions— will first remove the carboxyl group 

 from an amino-acid and convert it into an amine. The first 

 examples of change of this character are due to Ellinger, who 

 showed that putrescine and cadaverine — two of the best known 

 bases formed during putrefaction— may be produced by bacterial 

 action from ornithine and lysine respectively. This change will be 

 described further in a subsequent section. In most putrefaction 

 experiments, the amount of any particular base which is obtain- 

 able is very small. Faust, in his investigation of sepsine (Arch, 

 exp. Path. Pharm. 1904, 51, 248), allowed yeast to putrefy by the 

 hundredweight ; yet he obtained scarcely enough of the base 

 for analysis. In several experiments Barger and Walpole 

 could only isolate a few decigrams of />-hydroxyphenylethylamine 

 from 10 kilos of horse-meat, a quantity which must have been 

 capable of yielding at least 100 grams of tyrosine. Similarly, 

 when pure tyrosine, dissolved in broth, was putrefied by a 

 mixed culture, the yield of the amine, estimated physiologically, 

 was only o'3-o"5 per cent. In certain cases, however, the yield 

 may be much larger : Ackermann, working with pure histidine 

 and a mixed culture of bacteria, at once obtained nearly 30 per 

 cent, of the corresponding amine ; when pure cultures of 

 certain organisms are used, the yield in this latter case may 

 rise to 60 per cent. The cause for the small yields of most 

 experiments may be two-fold : organisms, which attack the 

 amino-acid in the wrong way, for instance by removing nitrogen, 

 may get the upper hand at the outset; moreover, as it is formed, 

 the amine may be decomposed by farther bacterial action. 



The process of decarboxylation which has been described is 

 apparently not limited to bacteria: "putrefactive" amines are 

 found in fresh ergot and contribute very largely to the activity 

 of this drug. 



Parajfmoid Amines derived ] from Amino- Acids. — Glycine should 

 yield methylamine and alanine (1-aminopropionic acid) ethyl- 



