K. Miyake: On the Nature of the Sugaes found in the Tubers of arrowhead. 33 



The residue was extracted with methyl alcohol, and the extract was con- 

 centrated to a syrup. The syruj) did not form any crystals even after standing 

 for 7 days. The syruj) was then treated with absolute alcohol to remove such 

 substances, which are soluble in this alcohol. On this treatment, slightly yellow 

 coloured powder was obtained. It did not give a sweet taste. We determined 

 its specific rotatory power, and obtained the following result. 



0.05 gram of this dried ix)wder was dissolved in water and made uj) into 10 

 cc. and j^olarized in 100 mm. tube. Bi-rotation was not observed. The rotation 

 was 1.5 on the scale toward the right. The specific rotatory power is 



(«)D= 1-5x0.346x10 ^ +103.5 (at 20°). 

 0.05 X 1 



The i3owder was once more treated with methyl and absolute alcohol respec- 

 tively as above mentioned and determined its specific rotatory power and found it 

 to be as follows : 



(a)'D= l-lxQ-^^^xlQ ^ + 103.7° (at 20°). 

 ^ ^ 0.0367 X 1 ^ 



We then tried to determine how much mucic acid is produced from the 

 ixjwder upon oxidation, and the following result was obtained. 



0.06 gram of the powder was dissolved in a small beaker with nitric acid of 

 sp. gr. 1.15 and oxidized in a boiling water bath in the usual manner. The 

 mucic acid produced was collected on a filter, washed and dried. The weight 

 of the crystals thus obtained was 0.0036 gram corresj^onding to 6^ of the powder. 



According to Creydt^"*, the quantity of mucic acid produced from 0.05 and 

 0.075 gram of raffinose is 0.0024 and 0.0056 gram in weight which corresix)nd 

 to 4:.S% and 7.5^ respectively. 



Consequently, it may be concluded that the powder under examination is 

 probably raffinose. 



6. Sii^ninari/. 



a. The reducing sugars of the aiTowhead tuber's consist of both glucose and fruc- 

 tose. As to whether or not the galactose is present as such or only in 

 combination with other hexoses, we have not sufficient data to decide, and 

 the question remains to be solved in future. 



1) Creydt,- I.e. 



