522 



Dr. E. F. 'Armstrong. 



[Apr. 5, 



But it is necessary to attribute a y-oxide formula to glucose and its 

 derivatives,* thus : — 



OH 



OH 



OH 

 -•H 



When E = H, the formula is that of glucose itself ; when E is an 

 alkyl radicle, it represents one of the alkyl glucosides ; when E is a 

 hexose residue (CeH^Oe-H), it represents a biose such as maltose. 

 The carbon atom to which the group EO is attached in this formula is 

 that which is figured as the superior carbon atom in the formula 

 previously given. 



Attachment of enzyme to hydrolyte. — The effect of hydrolysis, whether 

 by acids or enzymes, is to remove the radicle E and displace it by 

 hydrogen ; apparently, this change need in no way affect the oxygen 

 linkage in the ring. In the case of acids, although the attack may be 

 regarded as located on the OE radicle, it probably proceeds from the 

 neighbouring oxygen atom of the ring ;.f but there is every reason to 

 suppose that, in the case of enzymes, the enzyme becomes in some way 

 attached along the line of carbon atoms, thus : 



R0| 



— • 



* It is to be borne in mind that ordinary glucose in solution consists almost 

 wholly of two stereoisomeric compounds in equilibrium, together with, a very small 

 proportion, at the most, of the enolic form, the presence of which must be assumed 

 in order, among other reasons, to explain the results arrived at by Lobry de Bruyn, 

 which establish a reciprocal relationship between glucose, fructose and mannose in 

 solution. The argument which makes it necessary to attribute the y-oxide formula 

 to glucose and allied compounds is fully stated in the first of this series of papers 

 (' Chem. Soc. Trans.,' 1903, vol. 85, p. 1305) and in a paper by Dr. Lowry (loc. cit., 

 p. 314). The conclusions at which Dr. Lowry and I arrived have received inde- 

 pendent confirmation from the recently published work of Behrend and Roth 

 ('Annalen,' 1904, vol. 331, p. 361). 



f See Part I, loc. cit. 



