Oxidation of lactose

C (rapid heating). Manufactured by the oxidation of lactose or the galactans from wood with nitric acid. When heated with water it forms a soluble lactone. Converted to furoic... 

Saccharic acid. Use the filtrate A) from the above oxidation of lactose or, alternatively, employ the product obtained by evaporating 10 g. of glucose with 100 ml. of nitric acid, sp. gr. 1 15, until a syrupy residue remains and then dissolving in 30 ml. of water. Exactly neutralise at the boiling point with a concentrated solution of potassium carbonate, acidify with acetic acid, and concentrate again to a thick syrup. Upon the addition of 50 per cent, acetic acid, acid potassium saccharate sepa rates out. Filter at the pump and recrystaUise from a small quantity of hot water to remove the attendant oxahc acid. It is necessary to isolate the saccharic acid as the acid potassium salt since the acid is very soluble in water. The purity may be confirmed by conversion into the silver salt (Section 111,103) and determination of the silver content by ignition. 

Furoic acid has been made by oxidation of lactose followed by pyrolysis, by the oxidation of 2-acetylfuran, 2-methylfuran, or furfuryl alcohol using potassium ferricyanide in alkaline medium, and by other methods already listed. ... 

Lactose Abbadi et al. [22] have studied the oxidation of lactose, a co-product of the milk industry, on PtBi/C catalyst at pH 7. Lactobionate was formed transiently and subsequently converted into 2-keto-lactobionate with a final yield of... 

F g- 13.13 Principle of protein crosslinking by enzymatic oxidation of lactose coupled with the Maillard reaction [35-37]. 

Figure 2.37 Oxidation of lactose by alkaline copper sulphate (Fehling s reagent).

Stodola, F. H. and Lockwood, L. B. 1947. The oxidation of lactose and maltose to bionic acids by pseudomonas. J. BioL Chem. 171, 213-221. 

Bromine oxidation of lactose followed by hydrolysis gives D-gluconic acid and... 

Bromine oxidation of lactose followed by methylation and hydrolysis yields tetra-O-methyl-1,4-gluconolactone and the same galactose derivative as in (4). 

B. Jankiewicz and R. Soloniewicz, Continuous method for the oxidation of lactose to sodium lactobionate, Acta Pol. Pharm., 48 (1991) 7-10 Chem. Abstr., 118... 

P. Subbiah, K. layaraman, P. Thirunavukkarasu, T. D. Balakrishnan, and K. S. Udupa, Catalytic oxidation of lactose using electrogenerated bromide/hypobromite redox mediator, Bull. Electrochem., 3, (1987) 1—453 Chem. Abstr., 108 (1988) 157927. 

The indirect electrochemical oxidation of aldoses to the corresponding aldonic acids 273-27 ), which was carried out industrially as early as about 1930, is still used today for production on the tonne scale by Sandoz 27 S) and in India 276). Specific examples are the anodic oxidation of lactose to calcium lactobionate 275,277 278) ... 

Oxidation of lactose and maltose with Au/Ti02 catalysts has been reported to give close to 100% selectivity to lactobionic acid and malto-bionic acid, respectively63 which have potential uses in the pharmaceutical and detergent industries, as well as in food. Studies of the catalytic conversion of glucose by hydrogenation and oxidation to produce sorbitol and gluconic acid respectively have also been reported.64 Sorbitol is also manufactured on a 60 000 tonnes per annum scale. 

Derivation Oxidation of lactose or similar carbohydrates with nitric acid. 

Oxidation of Lactose (see galactose, SECTIONS 359 and 319).—Heat 10 grams of lactose on the water-bath with about four times its weight of concentrated nitric acid (28 cc.) until the brown oxide of nitrogen is formed. Keep the mixture at 70°-80° until the evolution of gas ceases. Dilute the solution with one-half its bulk of water and let it stand until cold, mucic and oxalic acids crystallize out. Filter, save the filtrate, and wash the crystals with warm alcohol to dissolve the oxalic acid, and then twice with a small amount of cold water. Recrystallize the residue, mucic acid, from a small amount of boiling water. 

One of the most important processes in the production of biochemicals is the 40,000 tons/yr lactic acid production involving the Lactobacillus oxidation of lactose. The MBR productivity increased eightfold compared to a conventional batch reactor with a 19-fold increased biomass concentration. Even a 30-fold increased production of ethanol was found upon coupling the Saccharomyces cerevisiae fermentation to a membrane separation. Other successful industrial applications involve the pathogen-free production of growth hormones, the synthesis of homochiral cyanohydrins, the production of 1-aspartic acid, phenyl-acetylcarbinol, vitamin B12, and the bio transformation of acrylonitrile to acrylamide. 

Mirescu and co-workers [384] have reported on the selective oxidation of lactose and maltose with Au/Ti02 catalysts. The initial activity for maltose was more than twice that for lactose but both reactions gave 100% selectivity... 

The selective oxidation of lactose to lactobionate with air on palladium-bismuth catalysts was first reported in patents [47]. Hendriks et al. [16] studied the oxidation of a 0.5 mol solution of lactose as a function of pH, temperature and Pd/Bi ratios of promoted Pd/C catalysts. Sodium lactobionate was obtained with 100% selectivity up to 95% conversion on Pd-Bi/C catalysts (Bi/Pd = 0.5) at 333 K and pH 9. Oxygen mass-transfer limited the maximum initial reaction rate (0.47 mol kg s ). The catalyst was recycled 15 times without any significant loss of activity and selectivity. 

Abbadi et al. [34] studied the oxidation of lactose and sodium lactobionate to... 

Mechanistic studies of hexacyanoferrate(iii) oxidation of lactose and maltose in alkaline media have been reported. In the presence of ammonium hydroxide,... 

Oxidation of lactose with bromine water followed by hydrolysis with dilute acid gives D-galactose and D-gluconic acid. 

Three dibasic acids of the series HOOC(CHOH)n-2COOH were likewise discovered very early, the C4 tartaric acid from wine lees, and the isomeric Ce mucic and saccharic acids from the nitric acid oxidation of lactose and of cane sugar. 

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