The alkaloids of Picralima klaineana / by T.A. Henry and T.M. Sharp.

  • Thomas Anderson Henry
Date:
[1927.]
Catalogue details

Licence: Public Domain Mark

Credit: The alkaloids of Picralima klaineana / by T.A. Henry and T.M. Sharp. Source: Wellcome Collection.

    6/16 page 1953
    crystalline residue of crude akuammine (alkaloid C). The latter was collected, washed with a little alcohol, allowed to dry in the air, and then treated with a slight excess of A^-sulphuric acid (2-8 c.c. approx, per gram) and sufficient water to dissolve it on boiling. The hot solution was treated with charcoal and filtered. On cooling, thin, colourless needles (m. p. 214—218°) of crude akuammine sulphate separated. The mother-liquor on concentration in a vacuous desiccator deposited more of the same sulphate, but finally dried up to a brown varnish. From this, by solution in dry alcohol, a further crop of akuammine sulphate can be obtained, but eventually an amorphous residue of the sulphate of alkaloid B is left. If ammonia solution is used in place of sodium carbonate for precipit¬ ation, the residue left after the removal of most of the akuammine sulphate sets to a jelly due to the presence of the sulphate of a hydrate of akuammine formed by the action of ammonia on this alkaloid as described later (p. 1958). The cold alcoholic extract of the ether-soluble portion of the precipitated alkaloids was taken to dryness under reduced pressure, dissolved in sufficient N-sulphuric acid to form a faintly acid solution, and to this was added a saturated aqueous solution of sodium iodide in water until no further precipitation occurred. After standing for a week, the clear liquor was poured off and the mixture of tar and crystalline matter that had separated was triturated with a little cold absolute alcohol, which dissolved the tar and left a small quantity of akuammine hydriodide. The alcoholic washings were added to the mother-liquors, and the whole was fractionally precipitated with sodium carbonate solution, the first few drops of precipitant serving to remove a dark brown, sticky base, from which a clear pale yellow mother-liquor was poured off. This on further addition of sodium carbonate solution yielded the crude alkaloid (B) as a pale yellow powder, m. p. 104° (air-dry) or 167° (dried in a vacuum). The seeds received from the Imperial Institute consisted of several samples collected at different times, and from one of these, on recrystallisation of the crude akuammine sulphate as described above, the first fraction consisted of the well-crystallised sulphate of alkaloid (D) (p. 1958). As only 2 g. of this alkaloid have been obtained, it has been considered advisable to conserve it for the present and only to make such observations upon it as would not entail the loss of material. It is therefore only possible to put its chief characteristics on record. The quantity of alkaloids present in P. Klaineana seeds is more than 5%, but the exact amount cannot be determined by any of the ordinary methods of estimation, because the alkaloids cannot
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