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.

    6/8 (page 122)
    The substance decomposed at about 202°-203°. Carbon and hydrogen, 0.1933 gm. subst., gave 0.2878 gm. C02 and 0.1035 gm. HoO. Calculated for C5H9O4N = C 40.81 ; H 6.12 per cent. Found . . . . = C 40.61 ; H 5.94 “ “ The filtrate from glutaminic acid hydrochloride yielded no definite substance. It did not seem to contain an appreciable quantity of aspartic acid, while neither here nor in the filtrate from phenylalanine hydrochloride of Fraction IV could preparations be obtained which gave evidence of the presence of serine. In the filtrates from gluta- minic acid hydrochloride of Fractions V and VI, after removal of the chlorine and subsequent conversion to the copper-salts, there was ob- tained, after slow concentration over sulphuric acid, a small quantity of copper-salt crystallizing in needle prisms, very unlike copper aspar- tate and of much greater solubility in water and which was possibly the copper-salt of a new amino acid. Unfortunately the amount of this substance was too small to warrant further investigation. Tyrosine. A quantity of hordein equal to 246 gm. ash and moisture free, \vas boiled with three times its weight of sulphuric acid and six times its weight of water for eight hours, and after removing the sul- phuric acid with an equivalent quantity of barium hydroxide the tyro- sine was separated by concentration and cooling. The crude tyrosine was dissolved in 5 per cent sulphuric acid and the solution treated with phosphotungstic acid. After removing the phosphotungstate precipitate the solution was freed from phosphotungstic and sulphuric acids with barium hydroxide and from barium with an equivalent quantity of sulphuric acid and 4.14 gm. of tyrosine separated by crys- tallization equal to 1.67 per cent. Nitrogen, 0.2333 gm. subst., required 1.81 c.c. 5/7 N—HC1. Calculated for C9Hn03N = N 7.73 per cent. Found ,...== N 7.76 “ “ The precipitate produced by phosphotungstic acid in the solution of the crude tyrosine was decomposed with baryta, and after removing the barium, the solution was concentrated and the precipitation with phosphotungstic acid repeated until the Millon’s reaction had ceased.