Natural Interconversion of Isomeric Sugars

Abstract

THE mechanism involved in the smooth transformation of one simple sugar into another is a matter of the utmost importance to the chemist and the physiologist alike, but little light was thrown upon the subject until Robinson¹ introduced the interesting theory that Walden inversion (conditioned by the enzymatic hydrolysis of phosphoric esters) within the sugar molecule is an agency for such changes. This hypothesis presents a simple and rational explanation of the conversion of glucose into galactose by the mammary glands during lactation, and lends colour to the suggestion that the primary constituent of nucleic acid is the commonly-occurring xylose, which undergoes conversion to ribose in an analogous manner. Mathers and Robertson², in a research on the hydrolysis of p-toluenesulphonyl esters of glucose, recently adduced evidence which strongly supported this view, in as much as they were able to convert a derivative of glucose into a derivative of altrose in one operation. Cognate researches have brought to light the following significant facts.