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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![crystallised out. Kraft also observed the formation of hydroergotinine (as he called the amorphous alkaloid), when a solution of ergotinine in 3 per cent, acetic acid is left standing for some days at the laboratory temperature. Shortly before the publication of Kraft’s results, we had indepen- dently observed the formation of ergotinine from ergotoxine in an attempt to acetylate the latter alkaloid. With this end in view, 0*64 gram of ergotoxine was boiled with 10 c.c. of acetic anhydride for a few seconds. The solution was then poured into water and stirred vigorously. The solution of the alkaloidal acetates was separated from a small quantity of a dark resin, and the alkaloids were pre- cipitated in the filtrate with ammonia, collected on a filter, and dried in a vacuum. The alkaloidal precipitate weighed 0*49 gram, and required for complete solution about 25 c.c. of boiling absolute alcohol, whereas the ergotoxine employed was soluble in very much less alcohol. On cooling, 0T3 gram of ergotinine separated out, and on concentration of the mother liquor 0'06 gram more, in all therefore about 30 per cent, of the theoretical yield. The identity with natural ergotinine results from the following : (1) The melting point was 220°, and remained unchanged when the substance was mixed with natural ergotinine. (2) the composition : 0*1153 gave 0*2895 C09 and 0*0668 H90. C = 68*48; H = 6*48. C35H3905N5 requires C = 68*91; H = 6*45. (3) The specific rotation in alcoholic solution : aD + 0*69° ; l 1 dcm. ; c = 0*200 ; [a]D + 345°. In a similar experiment the yield of ergotinine was* 25 per cent. ; for the specific rotation we found : aD + 0*95°; 1=1 dcm.; c = 0*245; [a]D + 388°. After boiling the alcoholic solution for half an hour: aD + 0*77° ; 1=1 dcm.; c = 0*231; [a]D + 326°. The mean value previously found for natural ergotinine after boiling with alcohol was [a]D-f 328°. At first we were unable to repeat Kraft’s experiment with methyl alcohol, perhaps because we used ergotoxine prepared by heatiug the phosphate on the water-bath with ammonia and filtering. Later, at Dr. Kraft’s suggestion, we liberated the base with sodium carbonate, extracted with ether, dried the ethereal solution with sodium sulphate, and evaporated it in a vacuum over paraffin wax. We then obtained from 0*139 gram of ergotoxine, dissolved in 2*4 c.c. methyl alcohol after four hours’ boiling on the water-bath, 0*031 gram of ergotinine = 23 per cent.](https://iiif.wellcomecollection.org/image/b22407479_0020.jp2/full/800%2C/0/default.jpg)
