The nucleic acid of the embryo of wheat and its protein compounds.

  • Osborne, Thomas B. (Thomas Burr), 1859-1929.
Date:
[1900]
Catalogue details

Licence: In copyright

Credit: The nucleic acid of the embryo of wheat and its protein compounds. 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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    of wheat embryo were so rich in leucosin, we determined the diastatic power of the germ meal by extracting with four times its weight of water and found that, under the conditions of Lintner’s test, o.iocc. of the extract so made, when added to 10 cc. of a 2 p. c. solution of soluble starch, formed within one hour, at 20°, enough sugar to reduce 5 cc. of Fehling’s solution. The O.IOCC. of extract corresponds to 25 milligrams of the germs, from which it is seen that this meal possesses high diastatic power, though it is inferior in this respect to active malt. Sodium Chloride Extract. Wheat germ meal treated with 10 p. c. sodium chloride brine forms a dense jelly-like mass from which it is nearly impossible to separate the solution. With 3 p. c. brine a manageable extract can be made by using from six to ten times as much solvent as meal. Thus, 100 grams of the meal treated with 600 cc. of 3 p. c. salt solution yielded in fifteen hours 400 cc. of clear filtrate. As has just been shown, the aqueous extract on dialysis, in consequence of a change which affects leucosin, deposits a large amount of proteid, chiefly in the coagulated form. In order to obtain preparations of the proteid substance soluble in salt solutions, but insoluble in water, which should be free from this coagu- lable albumin, we treated 2,000 grams of germ meal with 20 liters of 3 p. c. salt solution heated to 70°, whereby the leucosin was coagulated and the salt-soluble globulin brought into solution. The extract, neutral to litmus, was filtered clear, at once saturated with ammonium sulphate and the proteids thus precipitated collected on a filter, dissolved in water and the clear solution dialyzed in running water. Proteid matter separated on dialysis in spheroids which, like legumin, conglutin and amandin, united to a plastic mass on the bottom of the dialyzer. This precipitate was dissolved in brine, filtered absolutely clear, dialyzed for 48 hours, the large precipitate which sepa- rated allowed to settle, and the solution, which was nearly free from protein, decanted. A portion of the precipitate was washed first with water, which rendered it opaque and dense, then with dilute and finally 24