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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    Temp, of bath Fraction. up to Pressure. Weight. I 65° 20 mm. 22.1 gtn. From this fraction no glycocoll could be separated as the hydro- chloride of the ethyl ester. It seemed to consist largely of leucine and alanine and was accordingly added to Fraction II. Temp, of bath Fraction. up to Pressure. Weight. II 85° 9 mm. 38 4 gm. The esters of this fraction were boiled with water until the alkaline reaction had ceased. After evaporating to dryness under strongly reduced pressure, the proline was extracted with boiling alcohol and the part remaining undissolved subjected to fractional crystallization from water and from water and alcohol. There were obtained from the less soluble part 4.75 gm. of leucine and 0.8 gm. of substance of perfectly homogeneous appearance, which on analysis gave figures agreeing best with a mixture of equal parts of leucine and valine. Carbon and hydrogen, 0.1970 gm. subst., gave 0.3817 gm. C02 and 0.1716 gm. H20. Calculated for equal molecules of leucine and valine = C 53.12 ; H 9.66 per cent. C 52.84; H 9.67 Found {= The more soluble portion of this fraction was examined for glyco- coll, but none could be isolated as the hydrochloride of the ethyl ester. By systematic fractional crystallization there were obtained 2.72 gm. of alanine and 0.80 gm. of amino-valerianic acid. The alanine decomposed at about 290°. Carbo?i and hydrogen, I, 0.1418 gm. subst., gave 0.2114 gm. C02 and 0.0972 gm. HoO. II, 0.1538 gm. subst., gave 0.2268 gm. C02 and 0.1094 gm. H20. Calculated for C3H702N = C 40.45 ; H 7.86 per cent. Found = f I, C 40.66 ; H 7.61 per cent. ( II, C 40.22 ; H 7.90 “ “ The valine gave the following analysis: Carbon and hydrogen, 0.1351 gm. subst., gave 0.2546 gm. C02 and 0.1165 gm. H20. Calculated for C5Hu02N = C 51.28 ; H 9.40 per cent. Found .... =C 51.40; H 9.58 “ “