TRANSACTIONS. 



I. — The Cliemistry of Strophanthidin, a Decomposition Product of Strophanthin. By 

 Thomas R. Fraser, M.D., F.R.S., and Leonard Dobbin, Ph.D. 



(Read 7th December 1891. ) 



In a paper on the Chemistry and Pharmacology of Strophanthus hispidus, it was 

 pointed out by one of us that when strophanthin, the glucosidal active principle present 

 in the seeds and several other parts of this plant, is subjected to the action of dilute 

 acids, it yields, among other products, a crystalline body — strophanthidin. A brief 

 description was also given of processes by which this body may be prepared, and of 

 several of its characters and chemical properties.* 



The chemistry of strophanthidin will be more fully described in the present paper. 



Preparation. — Strophanthidin may conveniently be prepared by allowing a 5°/ o 

 solution of strophanthin, or of pure extract of Strophanthus, in 1*5 or 2°/ o sulphuric acid 

 to stand at the ordinary temperature for a few days. When this is done, the originally 

 nearly clear solution soon becomes hazy, the haziness gradually increases during the 

 following day or two, and then the solution again becomes clear, much glucose is found 

 to be present in it, and a deposit forms, which consists, for the most part, of crystals. The 

 crystals are usually sufficiently large to be apparent to the naked eye,t but sometimes 

 they are so minute that their crystalline form is recognisable only when they are magnified. 

 They are slightly coloured when prepared from the extract, but are almost colourless when 

 prepared from strophanthin. 



Crystalline strophanthidin may be produced in the cold not only by the action of dilute 

 sulphuric acid, but also of dilute hydrochloric, nitric, phosphoric, acetic, oxalic, and 

 hydrocyanic acid. It is, however, more rapidly produced by these acids at a temperature 

 of from 50° to 78° C, when it often appears in the form of long friable needles, from six 

 to ten millimetres in length ; but at higher temperatures, an amorphous coloured sub- 

 stance, and not an almost colourless crystalline body, is obtained. 



By the above process, so much as 37 / o of crystalline strophanthidin has been obtained 



* Trans. Roy. Soc. Edin., vol. xxxv. part iv. pp. 1004-1017. t Ibid., pi. vii. fig. 10. 



VOL, XXXVII. PART I. (NO. 1). A 



