Metabolism of Inositol 183 



lack of free rotation around carbon to carbon bonds, would permit a 

 clearer correlation between reactivity and the spatial arrangement of 

 the reactive groups. 



The measurement of the oxygen uptake of resting cell suspensions 

 of .4. suboxydans with several isomers of inositol as substrates revealed 

 that these compounds differed greatly in their susceptibility to en- 

 zymatic attack. Afi/o-inositol and e/n-inositol were oxidized with the 

 uptake of 1 gram atom of oxygen per mole and L-inositol, D-inositol, 

 and L-2-deoxy-mt/co-inositol (d-quercitol) were oxidized with the up- 

 take of 2 gram atoms of oxygen per mole, whereas scyllitol was not 

 attacked at all. 5 



The oxidation product of epi-inositol was isolated and found to be 

 a levorotatory ketoinositol which on reduction with sodium amalgam 

 yielded m?/o-inositol, indicating that the hydroxy 1 group in either posi- 

 tion 2 or 4 of epi-inositol had been oxidized. 5 Posternak isolated the 

 same keto compound and converted it by oxidation with permanganate 

 to a mixture of D-talomucic and D-glucosaccharic acid. 6 These re- 

 actions identified the Acetobacter oxidation product as D-2-keto-e/n- 

 inositol (XI). 



O 



'AO, / \| Na-Hg 



A. suboxydans 



VI XI 



The final products of the oxidation of d- and of L-inositol were iso- 

 lated by means of phenylhydrazine. Both products proved to be 

 bisphenylhydrazones of diketoinositols; they had identical melting 

 points, identical absorption spectra characteristic for osazones, and 

 optical rotations equal but opposite in sign. The consumption of 

 periodic acid corresponded to 3 moles of the oxidant per mole of bis- 

 phenylhydrazone. The products of this reaction were cyclic deriva- 

 tives of the dialdehydes expected in the periodic acid oxidation of 

 bisphenylhydrazones of a-diketoinositols. The racemic mixture of the 

 two enantiomorphic a-bisphenylhydrazones was found to be identical 

 with the osazone obtained by the treatment of the phenylhydrazone of 

 2-keto-wi/o-inositol (X) with phenylhydrazine. These reactions, 

 shown on the accompanying flow sheet, identified the oxidation prod- 

 ucts of d- and of L-inositol as L-l,2-diketo-?m/o-inositol (XII) and 

 D-l,2-diketo-mi/o-inositol (XIII), respectively. 5 



