ガスクロマトグラフィーによるＸｙｌｉｔｏｌの新しい定量法

• Published in: Japanese Journal of National Medical Services Vol. 38; no. 6; pp. 593 - 596
• Main Authors: YAMAMOTO Yuko, INOUE Taro, OTANI Yoshiki, YOKOTA Akira
• Format: Journal Article
• Language: Japanese
• Published: Japanese Society of National Medical Services 1984; 一般社団法人 国立医療学会
• Subjects: Touster回路; ガスクロマトグラフイー; キシリトール; 血中濃度
• ISSN: 0021-1699; 1884-8729
• DOI: 10.11261/iryo1946.38.593

Xylitol is a sweet, tasty pentitol (C5H12O5), which is a normal metabolite of Touster cycle. The exogenous xylitol is metabolized almost exclusively in the liver, and a major portion of xylitol is converted to glucose or glycogen. Therefore, hepatic function, espe-cially, activity of Touster cycle can be suggested by the elimination curve after xylitol loading.In this study, the development of a quantitative gas chromatographic method for the detection of xylitol in human blood is reported.Serum and dulcitol solution as internal standard were deproteinized by ultrafiltration, and the filtrate was lyophilized. Trimethylsilyl ethers were prepared by reacting the lyophilized powders with trimethylsilylating reagent (hexamethyldisilazane and trimethyl-chlorosilane in pyridine) for 15 minutes at 70°C. The supernatant was injected into the gas chromatograph.The gas chromatograph used was a Shimadzu Model GC-4CM, equipped with a hydro-gen flame ionization detector. Silicon OV-17/Silanox, 30m (L.), 0.3 mm (I. D.), Glass SCOT column was used, the column temperature was kept at 100°C for 5 minutes, and then was raised up to 200°C at the rate of 5 degrees a minute. The injector and the detector temperature was 230°C. Nitrogen was used as carrier gas with a flow rate of 1.8 ml/min, and a ratio of split was 1: 24.Calibration curve was made from a plot of xylitol concentration versus the ratio of the peak height of xylitol to that of dulcitol.As little as 2.5 ng xylitol can be detected. And better still, the recovery and the accuracy is satisfactory.The blood concentration of xylitol had a individual difference after oral administration. After a long-term oral administration, an adaptive increase of absorption was observed. The elimination rate of xylitol after one intravenous dose had been studied in normal subjects and liver cirrhotics. Touster回路の中間代謝産物の一つであるXylitolに着目し, ガスクロマトグラフイーにより, 血液中のXylitolを2.5μg/mlの低濃度まで検出できる方法を確立した. この方法は従来の定量法と比較して, キヤピラリーカラムを使用することにより特異性に優れ, 試料の前処理も極めて簡易であり, 再現精度も良好である. この方法によつて, 糖アルコール代謝に関する生理化学的情報も得られやすくなり, 非解糖系の動態解明に寄与することが出来るものと考えている.