Calcium “fructosate

The best source of D-fructose for large-scale purposes is probably the inversion of sucrose by acids or invertase. The separation of the ketose from the concomitant D-glucose may then be accomplished by direct crystallization, by removal of the d-glucose after oxidation with bromine to D-gluconic acid (the ketose is not affected), or by precipitation of the calcium fructosate. Hydrolysis of the natural inulins already mentioned may also serve for the preparation of D-fructose, which may be isolated from the hydrolyzate by precipitation of the lime complex.141 D-Fructose is fermented by yeast. 

Fructose-1,6-diphosphate (trisodium sait) [38099-82-0] M 406.1, pKj 6.14, pK 6.93 (free acid). For purification via the acid strychnine salt, see Neuberg, Lustig and Rothenberg [Arch Biochem 3 33 1943]. The calcium salt can be partially purified by soln in ice-cold M HCl (Ig per lOmL) and repptn by dropwise addition of 2M NaOH the ppte and supernatant are heated on a boiling water bath for a short time, then filtered and the ppte is washed with hot water. The magnesium salt can be pptd from cold aqueous soln by adding four volumes of EtOH. 

The calcium levulate precipitate was separated from the reaction mixture by filtration and washed with cold water. The precipitate was suspended in water to give a thick slurry, and solid carbon dioxide added until the solution was colorless to phenolphthalein. A heavy precipitate of calcium carbonate was now present and free fructose remained in the solution. 

The calcium carbonate precipitate was removed by filtration, and the filtered solution was found to contain 1,436 g of fructose as determined by optical rotation. A small amount of calcium bicarbonate was present as an impurity in solution and was removed by the addition of oxalic acid solution until a test for both calcium and oxalic acid was negative. The insoluble calcium oxalate precipitate was removed by filtration. 

Inorganic iron is absorbed only in the (reduced) state, and for that reason the presence of reducing agents will enhance absorption. The most effective compound is vitamin C, and while intakes of 40-60 mg of vitamin C per day are more than adequate to meet requirements, an intake of 25-50 mg per meal will enhance iron absorption, especially when iron salts are used to treat iron deficiency anemia. Ethanol and fructose also enhance iron absorption. Heme iron from meat is absorbed separately and is considerably more available than inorganic iron. However, the absorption of both inorganic and heme iron is impaired by calcium—a glass of milk with a meal significantly reduces availabiUty. 

Isolated liver segments from starved rats exposed to 100 mg KCN/L Oxygen consumption reduced 80%, and evidence of hepatotoxicity as judged by enzyme release, glutathione depletion, and calcium accumulation in liver. Hepatotoxicity prevented by feeding rats fructose 39... 

The formation of the biopolymer dextran is a complex process, where the fructose is known to inhibit the polymer chain growth. Consequently, the separation of the fructose from the reaction zone results in a higher molecular mass of the dextran even at high initial sucrose concentration [173]. In a first investigation, a fixed-bed chromatographic reactor was filled with calcium charged polystyrene. Fructose was retarded on this matrix while the dextran was prevented... 

Treatment of D-fructose or 1-O-substituted D-fructose with calcium hydroxide produced only the Q -D-glucosaccharinic acid (2-C-methyl-D-ri-bonic acid) and no jS-D-glucosaccharinic acid (2-C-methyl-D-arabinonic acid). However, when D-fructose was treated with sodium hydroxide, the D-glucosaccharinic acids were not detected. In order to confirm this... 

The composition of the products was monitored by HPLC (Sugar Analyzer, Waters Associates HPX-87C column, BioRad Corp. with deionized water, 40 ppm in calcium acetate as mobile phase). During fermentation, the sucrose levels dropped and fructan started to appear in 2 days thereafter, sucrose level gradually decreased as fructan increased. Glucose was the major by-product. A small amount of fructose and other unidentified fermentation products smaller in molecular weight were also observed. The pH of the growth medium was controlled, and fell from... 

The first, total synthesis of sugar-like compounds was performed as early as 1861 in that year, Butlerov2 reported the formation of methylenitan on treatment of aqueous formaldehyde with calcium hydroxide. The first, defined sugar derivative, DL-mannitol ( a-acrit ), was obtained by Emil Fischer and Tafel,3 and the first, optically active, totally synthetic sugars, D- and L-mannose and D- and L-fructose, were also prepared by Fischer.4... 

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