Determination of pseudo-alpha- and pseudo-beta-DL-glucose by gas-liquid chromatography, high-performance liquid chromatography, and enzymatic colorimetry with glucose 2-oxidase.

Three methods have been developed for measuring pseudo-alpha- and pseudo-beta-DL-glucose (pseudo-beta-D-glucose), synthetic compounds in which the ring oxygens of alpha- and beta-DL-glucose (beta-D-glucose) have been replaced by a methylene group. Moderate sensitivity in the determination of these pseudo-glucoses dissolved in human serum was obtained by GLC (0.1 nmol) and HPLC (0.5 nmol). The colorimetric determination with glucose 2-oxidase, peroxidase, and 2,2'-azino-di-(3-ethylbenzothiazoline-6-sulfonic acid) was satisfactory for the assay of pseudo-alpha- and pseudo-beta-DL-glucose (respective sensitivities: 25 and 5 nmol). The addition of hexokinase to the colorimetric assay system made it possible to eliminate glucose present in the sample, such as serum, and the remaining pseudo-alpha- or pseudo-beta-DL-glucose in the sample solution could then be measured by a colorimetric method using glucose 2-oxidase. The methods described can be used for biochemical studies involving pseudo-alpha- and pseudo-beta-DL-glucose.