Periodate oxidations properties

The application of periodate oxidation to a problem can best be considered in terms of an approach from two separate standpoints. The first generally involves the application of analytical techniques to semimicro quantities of material, and sometimes suffices to yield the desired information. After performing this preliminary, analytical investigation, the second or preparative phase may be undertaken. This entails use of much larger amounts of material, with the intention of isolating the end products of oxidation. If these are obtained, their properties should serve to confirm the results of the preliminary, analytical work and, if this is proved correct, the method is then available as a route to the desired synthetic compound. 

Thus one can draw the conclusion that there is no element in the periodic table, including other halogens and oxygen, that possesses stronger oxidizing properties than fluorine, which is really at the head of the oxidants series ... 

In 1954, Jeanes et al.5 reported the formation of glucan(s) by 96 strains of bacteria that were primarily Leuconostoc strains. (There is a question here as to whether they are strains or species, particularly with regard to the formation of different kinds of polysaccharides. The classification of the time was to place them into one species, mesenteroides, that had several different strains. This classification stands today.) The polysaccharides were characterized by various properties such as optical rotation, viscosity, periodate oxidation profile, and physical appearance after alcohol precipitation. The latter were observed to have different appearances, which were described by Jeanes et al.5 in various qualitative terms such as pasty, fluid, stringy, tough, long, short, flocculent, and so on. These differences in appearance provided an early suggestion of differences in structure (see Table I). Both water-soluble and water-insoluble polysaccharides were formed, and some strains seemed to form more than one kind of polysaccharide, as judged by their water solubility and by differences in the amount of alcohol needed to precipitate them. 

From this list of microorganisms capable of synthesizing dextran, it may readily be seen that one of the factors controlling the properties of the polysaccharide obtained is the strain of the particular bacterium used. This observation has been amply verified in a number of studies. Thus, immunological cross-reactions of dextrans with pnemnococcus antisera, the results of periodate oxidations, - and various physical measurements - have all demonstrated this point. 

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