Ammonia mutarotation

The surprising answer evolved for Lowry as he discovered that mutarotation ceases when traces of nitrogenous bases such as ammonia are removed from... 

Optical isomers of analogous tetranuclear species (hexols) containing other diamines have been reported for meso-2,3-bn (all eight possible optical isomers), R-pn (six isomers), and R,R-chxn (four isomers) (58,59). As observed for the ammonia hexol, some diamine hexol isomers have been reported to mutarotate (56, 58). 

CigHggOii, Mol. Wt. 342 3) +66 5°. Mutarotation of the solutions of dextrose, laevulose and lactose should be completed by the addition of a few drops of ammonia before being adjusted to volume (see also p. 604). 

The specific rotation (using a 20 per cent w/v solution containing a few drops of concentrated ammonia to complete mutarotation) should be +3° to —15 If added glucose be suspected it may be determined by the method given above. 

The values given in the table are for the equilibrium mixture in the case of a sugar which undergoes mutarotation. For rapid attainment of equilibrium, add a trace of ammonia to the sugar solution. For practical details, reference shoiild be made to books of practical physical chemistry. 

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