184 



Essays in Biochemistry 



A. suboxydans 



+ 2C 6 H 5 NHNH 2 

 NNHC 6 H 5 H 5 C 6 HNN 



NNHC 6 H 5 H 5 C 6 HNN 



H 



H 5 C 6 -N^ ^C-N = NC 6 H 5 

 I I 



N=C-CHO 



3HI0 4 



C 6 H 5 NHNH 2 

 NNHCHc 



-H..0 



HC-OH 



II 



C-N = NC 6 H, 



C = NNHC 6 H S 



CHO 



II 



CHO 



C = NNHC 6 H< 



I 

 C = NNHC 6 H 5 



CHO 



Phenvlhydrazone of X 



It was possible to isolate the monoketoinositol which is the initial 

 product of the action of A. suboxydans on D-inositol (IV). The com- 

 pound was identified as L-l-keto-?ni/o-inositol (XIV) by its oxidation 

 with resting cells of A. suboxydans to the diketone XII and by its 

 reduction with hydrogen catalyzed by platinum to ??i?/o-inositol (II). 7 



The product formed by the enzymatic oxidation L-2-deoxy-muco- 

 inositol (d-quercitol) (XV) was found to react with phenylhydrazine 

 to form a bisphenylhydrazone which had an absorption spectrum char- 

 acteristic of osazones and which reacted with periodic acid with the 

 uptake of 2 moles of oxidant. These observations indicated that the 

 keto groups were vicinal and that the three hydroxy! groups were 

 located on adjacent carbon atoms. The choice between the two pos- 

 sible structures was made by comparing the rate of oxidation by 

 periodic acid of this a-bisphenylhydrazone and the one prepared from 



