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The Chemical Educator
ISSN: 1430-4171 (electronic version)
Abstract Volume 20
(2015) pp 42-47
The Equilibrium of D-Glucose Anomers. Teaching a Venerable Subject Today
Albrecht Mannschreck
Department of Organic Chemistry, University of Regensburg, Universitätsstrasse 31, D-93040 Regensburg, Germany, albrecht.mannschreck@chemie.uni-regensburg.de
Received September 23, 2014. Accepted January 20, 2015.
Published: 2 March 2015
Abstract. Alpha- and beta-D-Glucoses are called anomers. They differ with respect to the axial and equatorial arrangements of the hydroxyl group at position 1. In the literature, the molecular structures of alpha- and beta-D-glucoses are determined by X-ray investigations. The anomer equilibrium is proven by 1H-NMR after equilibration (mutarotation), which occurs when crystals of the alphaor the betaisomer are dissolved. For this process, a recently published HPLC determination of the rate constants is described. The dehydrogenation of beta-D-glucose is an example of an anomer-selective reaction; its present-day application for the routine quantification of D-glucose in blood is discussed. The isomerization of the mixture of alpha- and beta-D-glucose-6-phosphates selectively yields alpha-D-glucose-1-phosphate. In this manuscript, today´s methods of investigation are applied, although only few of the results presented here were originally obtained by these methods. The article is suitable for chemistry students in their third or later years at the university.
Key Words: In the Classroom; biochemistry
(*) Corresponding author. (E-mail: albrecht.mannschreck@chemie.uni-regensburg.de)
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