Lactobionic acid calcium salt

The sequestering and emulsifying properties of lactobionic acid suggest a commercial potential for this product. In addition, it is a solubilizing agent for calcium salts. Solutions of calcium lactobionate containing up to 70% of the salt have been prepared and may be useful as a source of calcium (Kastens and Baldauski 1952). 

Calcium D-galactonate, I, 70 Calcium D-gluconate, III, 141, 142, 149, 152, 155, 156, 161 IV, 331 Calcium hypochlorite, III, 165 Calcium 2-keto-D-gIuconate, III, 148, 155 Calcium 5-keto-D-gluconate, III, 156 Calcium lactobionate, calcium bromide double salt, III, 155 Calcium Ievulinate, IV, 311 Calcium maltobionate, III, 161 Calcium D-mannonate, III, 152 Calcium pectate, I, 334 Calcium D-rhamnonate, III, 144 Calcium salts, in preparation of aldonic acids with NaCN, I, 23 Calcium vicianobionate, III, 154 Calcium D-xylonate, III, 155 Camphor, optically active, formed from inactive (racemic) camphor carboxylic acid in the presence of quinine, quinidine or nicotine, V, 53 Camphor carboxylic acid. See Camphor. Camphor, 3-hydroxy-, IV, 89 Camphorquinone, phytochemical reduction of, IV, 89... 

The application of this method of oxidation to the disaccharides without accompanying hydrolysis was successful and proved to be a valuable structural tool in showing the nature of the linkage between the two sugar units. Lactose was converted to lactobionic acid (33% yield) by Fischer and Meyer the sugar was treated with an equal weight of bromine at 20° for two days. Several salts were prepared, notably the insoluble basic lead salt, but the free acid would not crystallize. Ruff and Ollen-dorf reported a 38% jdeld, isolated as the calcium salt. Fischer and Meyer also reported the preparation of maltobionic acid, as the basic lead or calcium salt both were non-crystalline. 

In 1931, Isbell and Frush reported the electrolytic oxidation of aldoses in the presence of calcium carbonate and a small amount of bromide, which served as a catalyst. The main solutes in the reaction mixture are the aldose and the calcium salt of the aldonic acid. The latter is easily crystallized from solution. The salts of D-gluconic, D-xylonic, lactobionic and maltobionic acids were prepared. A description of the process was published in 1932 and a patent was issued in 1934. German and French patents were issued in 1931 to the Rohm and Haas Co. ... 

The 3rields of aldonic and oxalic acids are shown in Table XI. They are based on the amount of sugar oxidized (determined by reducing value) and not on the total amount of starting material. The formation of L-arabonic acid occurs with the highest percentage yield, but even this is low compared with other methods of preparation. As the lactobionic acid was isolated as the calcium lactobionate-calcium bromide salt, the actual amount of product, expressed in millimoles, is very low. 

Electrolysis of a solution containing calcium bromide and lactose causes smooth oxidation of the disaccharide to lactobiono-1,5-lactone, presumably by the formation of free bromine at the anode. After hydrolysis of the lactone, lactobionic acid is usually isolated as its insoluble calcium salt [(CjsH2iOi2)2Ca"5 H2O]. 

Definition Calcium salt of lactobionic acid Empiricai C24H42Ca024... 

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