Pilocarpine and the alkaloids of jaborandi leaves / by Hooper Albert Dickinson Jowett.

  • Jowett, H. A. D. (Hooper Albert Dickinson)
Date:
[1900?]
Catalogue details

Licence: In copyright

Credit: Pilocarpine and the alkaloids of jaborandi leaves / by Hooper Albert Dickinson Jowett. Source: Wellcome Collection.

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    Action of Caustic Potash on Pilocarpine and Isopilocarpine Methiodides. About 2 grams of the methiodide were dissolved in 20 per cent, aqueous caustic potash, and heated in a sealed tube at 180° for 4 hours. The product was then distilled, the volatile bases collected^ and the amount determined by titration with normal hydrochloric acid. The hydrochlorides were obtained by evaporation of the aqueous solution and examined. The liquid was now acidified with sulphuric acid and distilled, the distillate examined for volatile acids, and the acid liquid then extracted with ether for acids soluble in this medium. The liquid was afterwards made alkaline with ammonia, and extracted with chloroform for fixed bases. The residue was neutralised and evaporated to dryness, as it was intended to extract it with alcohol to see if any other product was formed, but the iodides present interfered with the operation, and it was abandoned. The following results were obtained : (1.) With pilocarpine. Volatile bases. The hydrochloride was entirely soluble in absolute alcohol and was obtained in three fractions, each fraction being con¬ verted into the platinichloride and analysed, giving Pt = 41'l, 41*1, and 41*0 per cent, respectively. The base was homogeneous and was methylamine. No acid or other product was obtained and the final residue gave no precipitate with copper acetate. (2.) With isopilocarpine. Volatile bases. The hydrochloride was entirely soluble in absolute alcohol and the platinichloride obtained in three fractions was analysed, giving Pt = 41*2, 41*2, and 41*4 per cent, respectively, thus proving the base to be methylamine. A trace of hydrocyanic acid was found, but no other product and no substance giving a precipitate with copper acetate could be isolated. The pyridinecarboxylic acids give a precipitate with copper acetate, and this reagent is generally used for separating and identifying them. Acetyl chloride has no action on these alkaloids, and they ara remarkably stable towards nitric acid. Cold fuming nitric acid has no action on either base, but on warming, pilocarpine is converted into isopilocarpine, which is not attacked even by warm fuming nitric acid unless the action be prolonged. Preliminary physiological experiments on isopilocarpine, pilocarpine, and pilocarpidine have been made by Prof. Marshall, of University College, Dundee, who reports that the substances produce similar