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.

    9/64 (page 153)
    saturated with ammonium sulphate and the large precipitate treated with about a liter of 10-percent, sodium chloride solution. A turbid liquid resulted which was not cleared by passing through filter paper but on standing became clear and the sediment was found to consist of gliadin, which is to be noticed later. Gliadin is soluble to a considerable extent in pure water and in water con- taining but a very small amount of dissolved salts, but the addi- tion of a little sodium chloride to its solution precipitates it com- pletely, After the solution had entirely cleared by subsidence it was dialyzed free from chlorides and heated to 65°. The result- ing coagulum was then filtered out, washed and dried in the usual manner and found to weigh 1.55 gram. The comjrosition of this preparation was as follows : Coagulated Rye Albumin, Leuoosin, Preparation 5. Aali-lree. Carbon 52.67 52.91 Hydrogen — 6.78 6.81 Nitrogen 16.57 16.65 Sulphur 1.40 1.40 Oxygen .... 22.23 100.00 Ash 0.47 The meal residue, from the water extract that yielded 5, was then treated with 10-per cent, sodium chloride solution and the filtered extract saturated with ammonium sulphate, the precipi- tate so obtained was filtered out, dissolved in water and sodium chloride solution and dialyzed till free from chlorides. The liquid was then filtered clear and heated to 65°. The coagulum washed and dried weighed 1,92 grams, being therefore considerably greater than the preparation obtained from the aqueous extract. It would appear therefore probable that the albumin forms a con- stituent of the aleurone grains which may not be broken up until treated with saline solutions. The following figures show the composition of this preparation : Coagulated Rye Albumin, Leuoosin, Preparation 6. Asli-frec. Carbon 52.55 52.77 Hydrogen 6,67 6.70 Nitrogen 16.61 16.68 Sulphur 1.29 i.29 Oxygen 22.56 100.00 Ash.. 0.42