The alkaloids of ergot. [Pt. I] / by George Barger and Francis Howard Carr.

  • Barger, George, 1878-1939.
Date:
1907
Catalogue details

Licence: In copyright

Credit: The alkaloids of ergot. [Pt. I] / by George Barger and Francis Howard Carr. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    a small quantity of sphserites and diamond-shaped plates. These were decomposed with ammonia in the same way as the amorphous salt, but yielded an amorphous base, which withstood all attempts at crystallisa- tion and was very readily soluble in alcohol. Later, it was found that a good yield of the same crystals could be produced by boiling the solution for a short time, and that they probably represent ergo- toxine phosphate. It 4s therefore probable that the crystalline sulphate mentioned by Tanret, and possibly also the halides which he analysed, together with the crystalline chloride obtained by Keller, were salts of ergotoxine. As we have shown, ergotinine is readily decomposed by very dilute phosphoric acid in boiling alcoholic solution, and, apparently, trans- formed to ergotoxine phosphate ; Kraft has found that ergotoxine is even produced in dilute acetic acid solution in the cold. We have also obtained from ergotinine small quantities of a crystalline picrate, but are unable to say whether it is a salt of ergotinine or ergotoxine. Keller found that the amorphous hydrochloride formed by precipitating an ethereal solution of the base with hydrochloric acid is soluble in water, but gives a precipitate with hydrochloric acid. This he attributed to the formation of an insoluble acid salt. We are unable to share this view. The salt is not only precipitated by hydro- chloric acid, but also by sodium chloride, sodium acetate, and sodium tartrate; not, however, by acetic acid, tartaric acid, carbamide, or sucrose. The precipitation therefore depends on the presence of ions and the solution of the salt is a colloidal one. Ergotoxine phosphate also gives a colloidal solution (see later). It is probable that the reason why organic acids are more suitable for the extraction of ergotinine from an ethereal solution than inorganic acids, depends on the small degree of ionisation of organic acids. The characteristic colour reactions for ergotinine have been described by Tanret (addition of concentrated sulphuric acid to a solution of ergotinine in ether or in ethyl acetate, giving a transitory orange coloration, changing to blue) and by Keller (anhydrous ferric chloride, added to ergotinine in concentrated sulphuric acid, changes the colour from pale yellow, through orange, crimson, and green to a permanent dark blue), Both these reactions are, however, given by ergotoxine with the same intensity as by ergotinine, since the two alkaloids naturally undergo the same decomposition by sulphuric acid. The behaviour of ergotinine solutions towards alkaloidal precipitants will be discussed later and compared with that of ergotoxine solutions. For a reply to Tanret’s recent criticism of our view, that ergotinine is physiologically inert, we must for the present refer to the paper by Barger and Dale (loc. cit.).