Galactose, determination

Lang et al. (1983) devised a microelectrode for galactose determination in tissue. In analogy to the respective glucose sensor, Dicks et al. 

Mosbach K and Mattiasson B 1976 Multistep enzyme systems Methods in Enzymology vol 44, ed K Mosbach (New York Academic) pp 453-79 Olsson B, Lundback H and Johansson G 1985 Galactose determination in an automated flow-injection system containing enzyme reactors and an on-line dialyzer A a/. Chim. Acta 167 123-36... 

B. Olsson, H. Lundback, and G. Johansson, Galactose Determinations in an Automated Flow-Injection System Containing Enzyme Reactors and an On-Line Dialyzer. Anal. Chim. Acta, 167 (1985) 123. 

Oxidation of galactose (or a galactose-containing sugar) to mucic acid. Dissolve 1 g. of galactose or lactose in a mixture of 10 ml. of water and 5 ml. of concentrated nitric acid contained in a small evaporating dish, and evaporate the solution to dryness on a water bath. Stir the cold residue with 10 ml. of cold water, filter off the mucic acid, wash it with cold water, dry and determine the m.p. (212-213° with decomposition). 

The stems of the tree were foimd to contain polysaccharides consisting of arabinose, galactose and galacturonic acid and only minor amoimts of rham-nose. Structural studies indicate that the polymeric material consists of 1,4-linked galacturonic acid residues, terminal, 1,4-, 1,6- and 1,3,6 galactose units and terminal and 1,5-linked arabinofuranose residues. Further studies must be performed on this in order to determine what type of pectin it can be classified as. The Hnkage data indicate that both AG-I and AG-II are present. This polymer was shown to activate polyclonal B-cells [78]. 

The determination of the sugar composition was performed with and without prehydrolysis to determine the cellulose content. Cellulose was present in soy meal and in WUS, the content was respectively 17.2 and 17.9 mol%. Both soy meal and WUS contained mainly galactose, glucose (cellulose), arabinose and uronic acids and their sugar compositions were very similar. This indicates that no sugar residues were specifically removed during the isolation procedure. 

Although the primary focus of oxidase based enzyme electrodes has been the determination of glucose, the list of extensions to other analytes is considerable. Systems have been described for cholesterol 123,132-136) galactose ii -i35-i37) dd i38.i39) lactatepyruvatecreatinine serum lipaseethanoland amino acids... 

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