Hydrolysis of excelsin / 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 excelsin / 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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    Histidine. The solution of the histidine, equal to 500 c.c. from 47.18 gm. of dry and ash-free excelsin contained nitrogen equal to 0.6945 gm. histidine or 1.47 per cent. 100 c.c. solution required 3.77 c.c. 5/7 N HC1 = 0.0377 gm. N in 100 c.c., or 0.1885 gm. in 500 c.c. = 0.6945 gm. histidine. This histidine was converted into the dichloride which crystallized in the rhombohedral crystals characteristic of this salt. These de- composed at about 2330. Chlorine, 0.0761 gm. subst., gave 0.0947 gm. AgCl. Calculated for QHnOoNaCl 2 = N 31.14 per cent. Found = N 30.76 “ “ Lysine. The lysine picrate obtained from 47.18 gm. of excelsin by the method of Kossel and Patten weighed 1.9884 gm. equal to 0.7725 gm. lysine picrate or 1.64 per cent. A Nitrogen, 0.3000 gm. subst., dried at no°, required 5.60 c.c. 5/7 N HC1 (Kj eldahl-Jodlbauer). Calculated for C6H1402N2 • C6H307N3 = N 18.70 per cent. Found = N 18.66 “ “ The results of this hydrolysis are given in the following table: Hydrolysis of Excelsin. Per cent. Per cent. Glycocoll Cystine . . not found Alanine ' • • 2.33 Oxyproline (C u Amino-valerianic acid . . . 1.51 Tyrosine .. . Leucine Arginine . Proline • • 3-65 Histidine . . Phenylalanine • • 3-5 S Lysine . Aspartic acid .... • • 3-35 Ammonia . Glutaminic acid . . . 12.94 Tryptophane . . . present Serine not found Total 61.09 No striking feature is shown by the hydrolysis of excelsin beyond the unusually large proportion of arginine that was found.