Studies on the proteids of rye and barley and on the chemical nature of diastase.

  • Osborne, Thomas B. (Thomas Burr), 1859-1929.
Date:
[1893]
Catalogue details

Licence: Public Domain Mark

Credit: Studies on the proteids of rye and barley and on the chemical nature of diastase. 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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    With reference to Martin’s statement concerning the presence of myosin—what is written on that point in the paper by Osborne and Voorhees on the Proteids of the Wheat Kernel applies equally to rye.* C. Proteid soluble in Alcohol. Gliadin. After extraction with sodium chloride solution, alcohol of 15 to 80 per cent, takes up a considerable quantity of proteid. 100 grams of rye meal were extracted thoroughly with 10-per cent, sodium chloride solution and then with YS-per cent, alcohol. The alcoholic extract was evaporated to very small volume and the separated proteid washed with water and ether and then dried. It weighed 3.93 grams, being therefore nearly 4. per cent, of the meal. 2000 grams of rye meal were then extracted with alcohol of 0.9 specific gravity, four successive times. Each extract, after filtering clear, was concentrated by distillation on a water bath. The first three extracts yielded on cooling a deposit of proteid but the fourth contained almost none. Each residue was then washed with water and dissolved in V5-per cent, alcohol. The substance from the first extract yielded an insolu- ble residue which when washed with dilute alcohol, absolute alco- hol and ether, gave preparation 8. This dried at 110° contained 17.00 per cent, of nitrogen. The solutions of the substances from the three extracts in dilute alcohol, were concentrated to about one- fourth their original volume and cooled, when the dissolved pro- teid separated. The substance from the first extiact was digested with absolute alcohol which dissolved a part of it, then with ether and dried, giving preparation 9. The residue from the second extract was washed superficially with water and then treated in a divided state with distilled water until dissolved. A little satui’ated sodium chloride solution was then added and the pro- teid wholly precipitated. The precipitate was then thoroughly dehydrated Avith absolute alcohol, digested Avith ether, and dried. This formed preparation 10. The proteid separated from the third extract Avas digested with absolute alcohol and with ether, and yielded a small quantity of proteid, preparation 11, which when dried contained, ash-free, 16.89 per cent, of nitrogen. Ihe absolute alcohol used in dehydrating preparation 9, Avith help of the Avater Avhich it extracted, dissolved a considerable quan- tity of proteid. This Avas precipitated by adding a feAV drops