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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![A sulphate, nitrate, hydrochloride, hydrobromide, two oxalates, and a tartrate, have been obtained crystalline, but only the phosphate, the oxalates, and the hydrochloride have so far been studied. The salts of ergotoxine with inorganic acids are very sparingly soluble in water, but readily so in hot alcohol, from which they can be crystallised. The salts with organic acids are more soluble in alcohol and are best crystallised by adding ether to their solutions in cold alcohol. Ergotoxine is, like ergotinine, a very feeble base and does not com- bine with more than one equivalent of acid. Its salts have an acid reaction; a crystal of the oxalate, for instance, produces a red spot when placed on moist blue litmus paper. Ergotoxine Phosphate, C35H4]06Nr),H3P04,H20. This is the most easily purified of the ergotoxine salts which we have so far examined, and was the starting-point in the preparation of the other salts. The crude phosphate obtained in the manner described under ergotoxine is decomposed by sodium carbonate, yielding the base, and this is precipitated in ethereal solution with phosphoric acid. After washing, the precipitated salt is dried and crystallised from alcohol, using 50 c.c. of 90 per cent, boiling alcohol for 1 gram of salt. With these proportions crystallisation should begin slowly, after one or two hours. It is important to use alcohol containing a little water, as the phosphate is much less soluble in absolute alcohol. When the crude salt is crystallised it separates in groups of needles radiating from centres and showing straight extinction, and, when pure, in isolated needles melting with decomposition at 186—187° (the bath being heated to 180° before the introduction of the substance). One part of ergotoxine phosphate dissolves in 313 parts of cold, and in 14 parts of boiling alcohol of 90 per cent. By shaking ergotoxine phosphate with cold distilled water, a typical colloidal solution can be obtained, containing 1 per cent, of the salt. This solution froths and is strongly opalescent, but does not deposit any of the salt on standing. The addition of an electrolyte (sodium acetate, sodium phosphate) converts the hydrosol into a gel. If equal volumes of A-hydrochloi ic, oxalic, phosphoric, or acetic acids are added to the solution, the degree of precipitation is in the order named, that is, in that of the conductivities of the acids. The hydrochloric acid produces a thick jelly, so that the test tube can be inverted, while the acetic acid leaves the solution fluid. It seems probable that this is one of the reasons why phosphoric and most organic acids are to be preferred to the stronger mineral acids in the extraction of ergot alkaloids. It has been shown already that a colloidal solution of](https://iiif.wellcomecollection.org/image/b22407479_0017.jp2/full/800%2C/0/default.jpg)
