Simple enzymatic method for determining 1,5-anhydro-D-glucitol in plasma for diagnosis of diabetes mellitus.
We have developed a simple method for determination of 1,5-anhydro-D-glucitol in plasma, based on use of pyranose oxidase (EC 1.1.3.10), an enzyme with specificity toward pyranoid compounds such as 1,5-anhydro-D-glucitol and glucose. Plasma samples deproteinized with trichloroacetic acid are passed through a two-layer mini-column packed with strongly basic anion (OH- form, the upper layer) and strongly acidic cation (H+ form, the lower layer) exchange resins. 1,5-Anhydro-D-glucitol is efficiently recovered in the flow-through fraction, which is almost devoid of other sugars that are sensitive to pyranose oxidase. The hydrogen peroxide formed in the enzymatic oxidation of 1,5-anhydro-D-glucitol is detected by a standard method utilizing an enzymatic color-developing system. The overall assay system is highly specific for 1,5-anhydro-D-glucitol. The correlation between results obtained in the present method (x) and in the gas-liquid chromatographic (GLC) method (y) was: y = 1.062x-0.293 mg/L (r = 0.997, n = 49, Sxy = 10.78 mg/L). Compared with GLC, our method is simpler in the sample treatment step and quicker in the measuring step. The precisions of the two methods are comparable.
Yabuuchi
M
M
Research Laboratory, Nippon Kayaku Co. Ltd., Tokyo, Japan.
Masuda
M
M
Katoh
K
K
Nakamura
T
T
Akanuma
H
H
D052160:Benzothiazoles; D002237:Carbohydrate Dehydrogenases; D002849:Chromatography, Gas; D003837:Deoxy Sugars / Q000097:blood*; D003847:Deoxyglucose / Q000097:blood*; D003920:Diabetes Mellitus / Q000097:blood / Q000175:diagnosis*; D006801:Humans; D013053:Spectrophotometry; D013451:Sulfonic Acids
D052160:Benzothiazoles; D003837:Deoxy Sugars; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; C006584:1,5-anhydroglucitol; D003847:Deoxyglucose; D002237:Carbohydrate Dehydrogenases; C022489:pyranose oxidase