2oG 



KINOSIIITA ; MANNANS IN C. KONYAKU. 



could be made in regard to its rotatory action upon polarised 

 light. Upon drying at ioo°, it lost its solubility in boiling water 

 entirely. Upon boiling with 4% sulphuric acid for several 

 hours mannose was also obtained from it. The property of losing 

 its solubility upon drying proves that this mannan is different 

 from that separated from yeast by Salkowski, (z) with which it 

 agrees, however, in the following respects : — 



Basic lead acetate — no precipitate ; basic lead acetate and 

 ammonia — thick precipitate; ferric chloride and ammonia — 

 gelatinous precipitate ; copper sulphate and sodium hydroxide — ■ 

 thick blue precipitate ; and the same by Fehling's solution. 



It seemed to me of interest to determine whether the diastase 

 of malt, invertase, or emulsin would have saccharifying power 

 over this slimy mannan of konyaku, and this I tried and found 

 not to be the case ; its slimy character remained, although I 

 digested it with the enzymes mentioned for 5-6 hours at 40 0 — 

 6o°, and no sugar was formed. 



That this mannan is also digested with much more difficulty 

 than starch, has been shown by Prof. Osawas experiments 

 on dogs. An enzyme endowed with saccharifying power for 

 mannan must, however, exist in the konyaku-root, and I intend 

 to try to isolate it in the season when the root is in the state 

 of developing shoots. 



(1) Ber. d. chem. Ges., 1894. p. 499. 



