186 



On the Poisonous Constituents of 

 Stephania hernandifolia. 



By Professor Edward H. Rexxie, M.A., D.Sc, and 

 E. F. Turxer. 



[ReadJune 6, 1893.] 



Some considerable time ago, Dr. Thomas L. Bancroft, of 

 Brisbane, forwarded to us for examination a quantity of the 

 roots of Steplicmia hernandifolia, Walpers. He had found that 

 an extract of the roots was exceedingly poisonous to frogs, and 

 published an account of his exiDeriments in vol. IV. (series 2nd) 

 of the Proceedings of the Linna^an Society of New South Wales 

 (27th November, 1889.) He pointed out that the physiological 

 action of the active substance appeared to be identical with that 

 of picrotoxin, the active princijDle of Cocculus, a genus of the 

 same order as Stephania, but having failed to obtain picrotoxin 

 from the plant, he suspected the poisonous effects to be due to an 

 alkaloid. 



In order to isolate the active substances, the following method 

 was adopted : — The roots cut up into fragments w^ere exhausted 

 with boiling alcohol, the alcohol distilled off, the residue extracted 

 repeatedly wath boiling water, and the solution filtered. While 

 still w^arm basic lead acetate was added, and the liquid filtered 

 again through linen. The excess of lead was then precipitated 

 by dilute sulphuric acid, and the acid liquid, after filtration, 

 extracted with chloroform. The chloroform having been distilled 

 off, the residue, wdiich was crystalline, was repeatedly recrys- 

 tallised from boiling water till colouiless and apparently pure. 

 Various samj^les of the substance thus prepared melted at tem- 

 peratures varying from 193° C. to 197° C. The substance so 

 obtained closely resembled picrotoxin in external characters, and 

 was intensely bitter. The melting point of picrotoxin is var- 

 iously given as from 199° to 201° C. Authorities differ as to its 

 exact composition, and it is apparently very liable to decomposition 

 and change. According to the latest and most authoritative 

 statements there are two substances, much alike, and both very 

 bitter and poisonous, called picrotoxin and picrotoxinin, the latter 

 arising from the decomposition of the former, the formulae 

 ascribed to these substances being respectively C3oH340]3 and 

 CioHifiOg 



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