THE STUDY OF CARBOHYDRATE METABOLISM. : II. ON THE APPLICATION OF HAGEDORN\u27S METHOD TO THE DETERMINATION OF CARBOHYDRATE IN VEGETABLES

In the study of the carbohydrate m etabolism of plants, it is frequently necessary to perform an accurate quantitative determination of carb ohydrate with only a minute amount of samples available. From this viewpoint, the author made a comparative study of several micromethods of determining sugar, in the preceding paper (1), and came to the conclusion that Hagedorn\u27s method is the most reliable. In the present paper the author examined Hagedorn and Jensen\u27s blood sugar method, to ascertain whether this method is applicable for micro determination of carbohydrate in vegetables, and found that it is available. The protein precipitant used by Hagedorn and Jensen also showed as good results as in proteins on the precipitation of tannins which are usually contained in vegetables. This method is only slightly effected by the excess of acid or salts, consequently the method is applicable to the determination of disaccharide which is easily convertible. The reducing power of glucose and fructose, against Hagedorn and Jensen\u27s reagent, is nealy equal but that of pentose is smaller. By the use of special amylase free from maltase, the author was able to determine starch as maltose. Hagedorn and Jensen\u27s method was found to be applicable to the determination of not only total and special carbohydrates but also of the determination of sugars. Hagedorn and Jensen\u27s method can be used with as minute quantity of sugar as one hundredth of the quantity used in Bertrand\u27s method.1. 微量定量法たるHAGEDORN & JENSEN 法を植物體の炭水化物の定量に應用し一般に使用する BERTRAND 法にて得たる結果と比較して近似なる値を得たり。但し HAGEDORN 法に於てBERTRAND 法の約四百分の一の供試品を使用するものなり。2. HAGEDORN & JENSEN 法は資料乏しき植物體に於ける炭水化合物の全量又は, 或特種なる炭水化合物の定量に利用され且濃度低き資料の冗量に使用しそ號べし。3. HAGEDORN & JENSEN 法は植物體の蛋白質單寧等を沈澱除去する場合には良き結果を興ふ。4. 此の方法は酸及び鹽の有在icよる影響少なるを以て還元糖のみならず多糖類を酸にて分解したる場合にも精密なる結果を與ふ。5. 葡萄糖果糖の HAGEDORN & JENSEN 示藥に對する還元力は夫れ夫れ近けれども Pentose の夫れは稍小なり。6. 澱粉の定量に於て Maltase 無き Amylase を使用し麥芽糖として定量し得たり