224 SCIENCE PROGRESS 



amine; however, little is known with certainty as to the 

 occurrence and origin of these two bases. 



The two amino-acids next in the series, valine and leucine, 

 both yield amines on putrefaction ; the amine corresponding to 

 the former acid, z'so-butylamine, has been obtained by the action 

 of bacteria on pure racemic valine ; the amine corresponding to 

 leucine, /so-amylamine, has been isolated from putrid yeast, 

 putrid horse-meat, etc. 



The formation of the latter base is represented by the 

 equation, 



™p CH . CH 2 . CH(NH,) . COOH = ch!> CH ■ CH2 ■ CH -' ■ NH - + COi 



The physiological activity of /so-amylamine was first established 

 by Barger and Walpole's identification of the base with 

 Abelous's pressor principle in putrid meat (further referred to 

 below under /-hydroxyphenylethylamine). This discovery was 

 of value, as it led to the examination by physiological tests 

 of the homologous fatty amines (Barger and Dale, J. Physiol. 

 1910, 41, 24). It was found that the simplest amine which had a 

 distinct pressor action (in doses of 1-2 c.c. of a decinormal solution) 

 was butylamine. In ascending the series, the activity increases 

 to hexylamine and then decreases again, a faint pressor action 

 still being observable with tridekylamine, C 13 H 27 NH 2 . On com- 

 paring the activity of amines containing the same number of 

 carbon atoms, the members of the iso-series were found to 

 be somewhat less active than the corresponding bases with 

 a straight carbon chain. 



The conversion of a monamine into a diamine completely 

 changes the physiological activity. Thus when pentamethylene- 

 diamine (cadaverine), NH 2 . CH 2 . CH 2 . CH 2 . CH 2 . CH 2 . NH 2 , is 

 injected intravenously it produces a fall of blood-pressure instead 

 of the rise caused by amylamine, the corresponding monamine. 



The two diamines, putrescine (tetramethylenediamine, 

 NH 2 .CH 2 .CH 2 .CH 2 .NH 2 ) and cadaverine (the next higher 

 homologue), originally discovered by Brieger in putrid material 

 of various kinds nearly thirty years ago, were almost the first 

 ptomaines that were thoroughly identified. They were soon 

 identified with synthetic bases of known constitution and have 

 often been met with by later investigators ; thus Udranszky 

 and Baumann found them in the urine in cystinuria (Zeitsch. 



