346 THE ACTIVE PRINCIPLE OF ERYTHROPHLOEUM LABOUCHERII, 



The general result of these experiments would refer the alkaloid to the 

 digitalis gi'oup in its pharmacological action. 



Discussion of Results. 



The alkaloids of E. Laboucherii and E. guineense compared. 



(a) Chemical Properties. 



The alkaloid of the Australian species closely resembles the description of 

 Merck's pure erythrophleine. Both alkaloids and all their salts were uncrystal- 

 lisable syrups. The hydrochloride, prepared under the most careful conditions, 

 was obtained as a viscous yellow oil, which dried into a brown solid glutinous 

 mass : in this lespect it resembled the product of Merck, and of Power and 

 Salway. 



Harnack's provisional formula for erythrophleine, C28H43O7N, was 

 obtained from the amorphous platinum salt, and represents a molecular weight 

 of 505. 



Power and Salway obtained an approximate agreement of the above formula 

 from the analysis of the hydrochloride, which they prepared from a sample of 

 Merck's erythrophleine. This hydrochloride salt yielded to the authoi-s (6.9% 

 CI) 7.1% HCl and corresponds to the formula B.HCl (B=l molecule of Base). 



The alkaloid from the Australian species, on the other hand, when titrated 

 with the greatest care gave 3.64% of hydrochloric acid, just half the amount 

 obtained by Power and Salway. This amount, however, corresponds to the 

 formula [BJa .HCl. 



[C28 H43 O7 N] .HCl requires 7.21% HCl. 



[C28 H43 O7 N]2 .HCl „ 3.61% HCl. 

 Accepting the latter as the formula of the hydrochloride obtained from the 

 Australian Erythrophloeum, the agreement in the molecular weight thus found 

 is so close as to justify the conclusion that the alkaloid is identical with the 

 erythrophleine of the African species. 



(h) Physiological Properties. 



The violent effects produced on the respiratory organs by this plant, during 

 the gi'inding and preparing of the sample for analysis, were also experienced 

 and noted by all the investigators of E. gwrteens-e. 



In the examination of a pharmacologically active plant, the collective effects 

 produced in the animal body by the active principle arc referred to certain 

 types or groups of substances. In this way we obser\e the action of the 

 atropine group, the curare, or the digitalis group. The action of the digitalis 

 group is recognised chiefly by a special action on the cardiac muscle, with 

 which there is a strengthening of the systolic phase of the heart and finally 

 complete stoi)ping of the ventricle in systole. 



The substances which produce these effects are certain organic compounds, 

 mostly glucosides, wliicli have been obtained from plants, and include digitalis, 

 apocynin, antiarin, convallamarin, hcUeborcin, olcandrin, scillain and some of 

 the African arrow-poisons. 



The general action of the digitalis group as indicated above, was observed 

 in all the experiments on frogs and dogs carried out with the alkaloid of 

 Kriith rophlorum Lnboiicherii. 



