7 o SCIENCE PROGRESS 



dextro isomer. The racemic substance was resolved by Flacher 

 by means of its acid tartarate in 1908, and /-adrenalin is now 

 manufactured by this method under the name of " suprarenin " 

 by the Farbwerke vorm. Meister, Lucius u. Briinning. 



Adrenalin is related to the simpler substance /3-p-hydroxy- 

 phenylethylamine, 



HO (~ ~\ CH 2 . CH 2 NH 2 , 



which Barger and Walpole identified in 1909 as the chief pressor 

 principle occurring in extract of putrid meat and ergot. It is 

 produced by fermentation of tyrosine, 



HO f" ~\ CH 2 . CH(NH 2 )C0 2 H, 



one of the amino acids, which, like small magnets having positive 

 and negative poles, form the links of which the highly complex 

 proteins are composed. It seems probable that /3-p-hydroxy- 

 phenylethylamine, formed by putrefaction in the human intes- 

 tine, is the cause of the high blood pressure observed in certain 

 persons, to which Metschnikov has suggested that arterio- 

 sclerosis in old age is due. The physiological effect of this 

 substance is about one-twentieth that of adrenalin. The pro- 

 duction of /3-/>-hydroxyphenylethylamine from tyrosine, by loss 

 of carbon dioxide on fermentation or heating, is typical of a 

 general method for the formation of amines from the corre- 

 sponding amino acids. Thus valine, VI., gives iso-butylamine, 

 VII. ; and tryptophane, VIII., another of the decomposition 

 products of the proteins, yields 3-/9-aminoethylindole, IX. : 



(CH 3 ) 2 CH.CH 2 .CH(NH 3 )C0 2 H -> (CH 3 ) 2 CH . CH 2 CHNH 2 ; 



VI. VII. 



f\- -jjC . CH 2 . CH(N Ho) . C0 2 H f^ -C . CH 2 . CH 2 NH 2 



NH NH 



VIII. IX. 



All the fatty amines from butylamine to trydekylamine have 

 an appreciable pressor action. The introduction of a hetero- 

 cyclic or aromatic nucleus causes considerable increase in 

 physiological activity, which becomes further enhanced in those 



