Hydrolysis of hordein : by Thomas B. Osborne and S.H. Clapp.

  • Osborne, Thomas B. (Thomas Burr), 1859-1929.
Date:
[1907]
Catalogue details

Licence: In copyright

Credit: Hydrolysis of hordein : 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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    to Reprinted from the American Journal of Physiology. Vol. XIX.—June i, 1907. — No. I. HYDROLYSIS OF HORDEIN.1 By THOMAS B. OSBORNE and S. H. CLAPP. [From the Laboratory of the Connecticut Agricultural Experiment Station.] HE seeds of barley, like those of other cereals, contain a rela- tively considerable amount of protein soluble in alcohol of from 70 to So per cent by volume. An investigation of this seed, which was made some years ago in this laboratory, gave no evidence of the presence of more than one protein soluble in alcohol.2 Ex- tensive fractionations of this protein yielded products of the same composition and properties, and it was therefore proposed to call it hordein. The composition of hordein as shown by closely agreeing analyses of a large number of different preparations is: C 54.29; H 6.80; N 17.21 ; S 0.83 ; O 20.87 per cent. The preparation of hordein used for this hydrolysis was made from freshly ground barley flour3 by extracting with cold 75 per cent (by volume) alcohol. The alcoholic extract was filtered perfectly clear and concentrated to a thin syrup on a water bath at about 700, under strongly reduced pressure. This concentrated solution was then poured into a large volume of distilled water containing much pure ice and, after washing with water, the precipitate was again dissolved in 75 per cent alcohol and its clear solution poured into several vol- umes of absolute alcohol. The resulting precipitate of hordein was digested with absolute alcohol until thoroughly dehydrated and the alcohol removed in the desiccator by sulphuric acid. A sample of the hordein thus prepared, after grinding fine and drying at iio°, was extracted for a long time with ether but yielded only traces of sub- stance soluble therein. 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 American Chemical Society, 1895, xvii, p. 539. 8 We are indebted to Dr. Frank Fuller of the Health Food Company of New York for this barley flour which he ground expressly for us. We wish here to express our thanks for his kind assistance.