THE UTILIZATION OF CERTAIN PENTOSES 
Table IV 
Comparative Effect of Boiled and Unboiled Extract of Fungus Mycelium upon Xylan 
from Rye Straw as Shown by Alcohol- soluble Furfur ol-yielding Material and 
Substance Reducing Fehling's Solution 
Duration of 
Experiment 
Amount of Xylan in 
Each Preparation 
Cuprous Oxide Derived from 
Material Reducing Fehling's 
Solution. 
Amount of Pentoses 
Unboiled 
Boiled 
Unboiled 
Boiled 
g- 
mg. 
mg. 
mg. 
mg. 
6 days 
8 " 
0.3 
123.8 
31.5 
67.5 
9.2 
0.3 
93-6 
18.I 
52.1 
8.3 
8 " 
0.2 
70.5 
12. 1 
46.7 
8.1 
10 " 
0.3 
133.0 
31.4 
67.8 
9.5 
10 " 
0.2 
108,2 
17.6 
47.4 
9-5 
shaped crystals soluble in hot water, insoluble in cold, and melting at 
i6i°-i62° C. uncorrected, as compared with 161° C. for xylosazones 
prepared from the xylose sugar obtained from rye straw and from the 
commercial xylose as used in the experiments already described. 
Some of the control preparations were treated in a like manner, but 
the quantity of osazone formed was so small that it was impossible 
to identify it with certainty. 
It is obvious from Table IV that there is much more alcohol- 
soluble substance which reduces Fehling's solution and furfurol- 
yielding substances in the unboiled preparations than in the boiled 
controls. That this increase is not due to the autolysis of the filtered 
extract of the fungus mycelium itself was proved by the fact that when 
the extract was accorded exactly the same treatment as the unboiled 
preparations no appreciable amount of reducing substance was found 
and no measurable amount of furfurol-yielding material. The above 
mentioned considerations and the fact that the phenylhydrazine deriv- 
ative is similar to the osazone of xylose seems to show that xylose re- 
sults from this action of the unboiled extract of fungus mycelium 
upon the xylan. 
Whether this hydrolysis takes place immediately or the amount 
of alcohol-soluble reducing substance and furfurol-yielding material 
present at the completion of the experiment is the i-esult of a gradual 
breaking down of the xylan is now shown by the results already given. 
Further experimentation was necessary to obtain evidence upon this 
point. In these experiments twelve or more similar preparations 
were made, as already described, several of which were boiled as 
