The alkaloids of ergot. [Pt. I] / by George Barger and Francis Howard Carr.
- George Barger
- Date:
- 1907
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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![This specimen gave : aD + 0*90° ; l=\ dcm. ; c = 0T244; [a]D + 328°. In a similar experiment, when ammonia was used to liberate the base, we obtained a somewhat smaller yield, and in no case was the transformation even approximately quantitative. As we have already observed, we infer from our experiments on the optical rotation of ergotinine that the alkaloid undergoes decomposition by prolonged boil- ing in alcoholic solution. Since we originally regarded ergotinine as acetylergotoxine, we attempted to hydrolyse it by means of an acid, and selected phosphoric acid because the phosphate is the most characteristic of ergotoxine salts. 0'3 gram of ergotinine, which would require nearly 20 c.c. of boiling absolute alcohol for solution, was heated on the water-bath with 6 c.c. of alcohol containing 1^ molecular propor- tions of phosphoric acid. At 70° the ergotinine did not readily dis- solve, but after boiling for fifteen minutes solution was complete. On standing overnight, 0*2 gram of minute diamond-shaped plates sepa- rated out, consisting of long needles of which each end is symmetric- ally replaced by two dome faces; the extinction is parallel to the long edge of the crystals. They were found to be the phosphate of an amor- phous base. On recrystallisation from alcohol and ether much larger plates were obtained, mostly hexagonal or triangular in shape, and differing completely from the slender prisms of ergotoxine phosphate already described. Nevertheless, both phosphates melted at 186—187°, and a mixture of the two showed the same melting point. This new phosphate was converted into the oxalate, which melted at the same temperature as normal ergotoxine oxalate, and resembled it in crystal- line form. Finally, the oxalate was reconverted into the phosphate, which was found to have preserved its original crystalline form. Its identity with ergotoxine phosphate we have not as yet definitely established for want of material, but possibly the one is a racemic modification of the other. Both salts show great physiological activity. In order to prove the absence of acetyl groups in ergotinine, its solution in 20 per cent, aqueous phosphoric acid was distilled with steam. No acid passed over. On neutralisation and concentration the solution yielded the typical prisms of ergotoxine phosphate. In conclusion, we wish to acknowledge our indebtedness to Mr. W. C. Reynolds, B.Sc., for much help in the isolation of the alkaloids, and to Mr. A. J. Ewins, B.Sc., for valuable assistance throughout the work. The Wellcome Physiological Research Laboratories, Herne Hill, London, S.E.](https://iiif.wellcomecollection.org/image/b22407479_0021.jp2/full/800%2C/0/default.jpg)
