On the toxic Constituents in the Bark of 
Robinia pseudacacia L. 
(Report I.) 
By 
Buhachirö Tasaki and Ushio Tanaka. 
Introduction. 
In the year 1890, B. Power and J. Camprer! found a toxic albumose 
in the aqueous -extract of the bark of Robinia pseudacacia L. Afterwards 
this toxic constituent was termed ‘robin’ by FRIEDRICK B. Power’ (1901). 
According to him, robin, a precipitate from the aqueous extract with acid, 
has the properties of nucleoprotein, containing a large quantity of iron in its 
ash. It coagulates by heating from its water solution, complete coagulation 
taking place at 70—80°C. whereby it loses its toxic action. But, when prepared 
from the aqueous extract with strong alcohol, it is considered to have the 
nature of a ferment, as it decomposes amygdalin. By the action of robin, the 
blood corpuscles of certain animals agglutinate as is the case with ricin, crotin 
and abrin, and milk caseinogen coagulates as with chymosin. When decom- 
posed, an alkaloid-like substance is obtained. 
Treating the aqueous extract with hydrochloric acid, POWER found a 
crystalline, a noncrystalline substance (named syringenin) and a levorotatory 
sugar. ‘This crystalline substance was found to be syringaic acid on account 
of its constitution and melting point, so that he supposed the existence of 
a glucoside ‘syringin’ in the bark, which decomposes by hydrolysis into 
syringaic acid, syringenin and sugar. But he said nothing about the toxicity 
of this glucoside. 
1. Jahresberichte der Pharmacie. 1890. 
2. „ „ „ 1901. 
[Jour. Coll. Agrie., Vol. III, No. 5.] 
