Chemical examination of wheat germ / by Frederick B. Power and Arthur H. Salway.

  • Power, Frederick B. (Frederick Belding), 1853-1927
Date:
[1913?]
Catalogue details

Licence: Public Domain Mark

Credit: Chemical examination of wheat germ / by Frederick B. Power and Arthur H. Salway. Source: Wellcome Collection.

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    rhombohedral prisms, which decomposed at about 238°. This substance possessed all the characters of allantoin, and its identity was confirmed by an analysis. 0 1477 gave 0-1654 C02 and 0 0514 H20. C = 30 5 ; H = 3-9 C4HVO3N4 requires C — 30 4; H = 3*8 per cent. Isolation of Betaine, (^HuC^N, and Choline, C5H15OaN. Although the occurrence of both betaine and choline in wheat germ had been definitely established by Schulze and Frankfurt (.Ber., 1893, 26, 2151), it was deemed desirable, for the sake of completeness, to confirm their presence in the material under investigation. For this purpose a portion of the syrupy liquid was employed which had been purified by means of basic lead acetate, as already described. To this liquid an aqueous solution of phosphotungstic acid was added, when a voluminous precipitate was produced, which was collected, and washed with water. The preci¬ pitate was then intimately mixed, in the cold, with aqueous barium hydroxide, the mixture filtered, and the excess of baryta removed from the filtrate by means of carbon dioxide. After being again filtered, the liquid was rendered faintly acid by the addition of a little hydrochloric acid, and then concentrated under diminished pressure to the consistency of a syrup. The latter was digested with hot alcohol, and to the filtered liquid an alcoholic solution of mercuric chloride was added. On keeping the mixture for several days, a crystalline double mercuric salt separated, which was col¬ lected, dissolved in hot water, and decomposed by hydrogen sulphide. The filtrate from the mercuric sulphide was con¬ centrated under diminished pressure, when a residue was obtained which quickly crystallised. This product was treated with cold absolute alcohol, when a portion, which was very sparingly soluble in the latter liquid, remained undis- solved. The concentrated aqueous solution of this sparingly soluble salt, on the addition of gold chloride, yielded an aurichloride which slowly separated in glistening laminae, and was analysed. 0T287 gave on ignition 0-0555 Au. Au = 43T. C5H1202N.AuCh requires Au = 43-2 per cent. The presence of betaine in wheat germ was thus confirmed. The portion of the above-mentioned crystalline product which was readily soluble in alcohol was recovered by the