The hydrolysiis of gliadin from rye / by Thomas B. Osborne and S.H. Clapp.

  • Thomas Burr Osborne
Date:
[1908]
Catalogue details

Licence: In copyright

Credit: The hydrolysiis of gliadin from rye / by Thomas B. Osborne and S.H. Clapp. 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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    Reprinted from the American Journal of Physiology- Vol. XX.—January i, 1908. — No. IV. THE HYDROLYSIS OF GLIADIN FROM RYE.1 By THOMAS B. OSBORNE and S. H. CLAPP. [From the Laboratory of the Connecticut Agricultural Experiment Station.] LCOHOL extracts from rye flour a protein substance which very closely resembles gliadin obtained from wheat flour under similar conditions. The gliadin from rye has been the subject of extensive study in this laboratory,2 and a strict comparison in respect to composition and reactions has been made between it and the gliadin from wheat without revealing any differences. This com- parison has now been supplemented by a determination of the pro- portion of the several decomposition products which the gliadin of rye yields when hydrolyzed. The material for this hydrolysis was obtained by extracting rye flour, ground in this laboratory, with cold 75 per cent (by volume) alcohol, concentrating the perfectly clear extract under reduced pressure to a syrup, and precipitating the gliadin by pouring the solution into ice water. The precipitate thus obtained was redissolved in 85 per cent (by volume) alcohol, and the solution again poured into several volumes of ice water. The gliadin that separated was then washed with distilled water, redissolved in 85 per cent alcohol, and the clear solution precipitated by pouring in a thin stream into a large volume of absolute alcohol. After dehydrating by long digestion with absolute alcohol, the gliadin was dried over sulphuric acid, ground to a fine powder, and moisture, ash, and ether soluble matter determined in it. Four hundred and fifteen grams of this preparation, equal to 362.67 gm. moisture, ash, and fat free, were suspended in a mixture of 415 c.c. of water and 415 c.c. of hydrochloric acid of sp. gr. 1.19. After warming for three hours at ioo° the hydrolysis solution was boiled in a bath of oil for eighteen and a half hours. 1 The expenses of this investigation were shared by the Connecticut Agricul- tural Experiment Station and the Carnegie Institution of Washington, D. C. 2 Osborne: Journal of the American Chemical Society, 1895, xvii, p. 429.