246 
K. OSHIMA & T. TADOKORO. 
Müller 15 , phenylisocyanate method of H. SteudeP, oxidation method 
(norisosaccharic acid) of N e u b e r g-lV o 1 f f 1 2 3) 4 and the direct method of A. 
Oswald. 45 Of these, the last method by Oswald is simplest and allows, 
at the same time, the direct identification of glucosamin as such. We have 
therefore attempted to detect glucosamin in the hydrolysis product of the 
yam mucin according to Oswald’s method. 
6 grams of the dry preparation were mixed with 240 c.c. of 3”/o hydro- 
chloric acid and heated in a water bath for 10 hours, with a reflux con- 
denser. The dark brown liquid was filtered, concentrated slowly on a water 
bath to a syrup and then kept over sulphuric acid. Xo characteristic crys- 
tals of glucosamin hydrochloride appeared even after standing for several 
weeks. The syrup, however, gave Molisch’s reaction as well as biuret reaction 
very strongly. Our failure to obtain glucosamin hydrochloride was evidently 
due to the lack of favorable conditions for its separation. 
We have therefore tried to isolate it as osazone from the syrup. The 
syrup was diluted with water and precipitated with phosphotungstic acid in 
the usual manner. The neutralized syrup was heated with 2 parts of phenyl- 
hydrazin hydrochloride and 3 parts of sodium acetate in a water bath for 
1J hours. Characteristic crystals of phenylglucosazone appeared, which when 
cold was filtered and recrystallized from 60 % alcohol. The melting point 
of the osazone was determined and 'found to be 203°. Consequently it is 
probable, if not conclusive, that the syrup contained glucosamin. 
Having failed with Oswald’s method, we had attempted to identify 
glucosamin with Neuberg-Wolff’s method in the following manner. 
30 grams of the preparation were mixed with 40 c.c. of fuming hydro- 
bromic acid, sp. gr. 1.49, and allowed to stand for 2 hours in cold with 
frequent shaking. At the end of this time, when the whole mass appeared to 
have been gelatinized, it was diluted with 200 c.c. of water and heated 
gently in a water bath for 1J hours with a reflux condenser. The dark 
1) Zs. f. Biol., 42 (1901), pp. 468—564. 
2) Hoppe-Seylers Zs. physiol. Chem. Strassburg, 34 (1902), pp. 353 — 384. 
3) Ber. D. chem. Ges., Berlin, 34 (1901), pp. 3840 — 3846. 
4) Hoppe-Seylers Z.s. physiol. Chem. Strassburg, 68 (1910), pp. 173 — 180. 
