Alginic acid periodate oxidation

The presence in alginic acid of L-guluronic acid residuesi (which escaped detection until quite recently) has been further confirmed by the isolation of L-(-t-)-threaric acid from the product obtained by periodate oxidation, treatment with bromine, and acid hydrolysis.i °< ... 

Oxidation of Alginic Acid. Fifteen grams (0.086 equivalent) of dried al nic add (LI or LII) is stirred vigorously with 426 cc. of 0.380 M periodic add solution until peptized, which requires about one and one-half hours. The mixture is kept at room temperature for twenty to twenty-four hours, during which time periodic add is reduced (1.1 mole per equivalent of al nic add). The oxidation proceeds comparatively rapidly during the first two hours. Addition of 1600 cc. of i-butyl alcohol throws down an amorphous predpitate. This i centrifuged down and washed four times with 60-cc. portions of aqueous i-butyl alcohol... 

T. 1. Painter and B. Larsen, Formation of hemiacetals between neighboring hexuronic acid residues during the periodate oxidation of alginate, Acta Chem. Scand, 24 (1970) 813-833 T. 1. Painter and B. Larsen, Transient hemiacetal structures formed during the periodate oxidation of xylan, Acta Chem. Scand, 24 (1970) 2366-2378. 

Alginic Acids.—Theoretical and practical aspects of the oxidation of alginates with periodate have been discussed. " ... 

PAINTER T. and LARSEN B. 1970. Formation of hemiacetals between neighbouring hexuronic acid residues during the periodate oxidation of alginate. Acta Chemica Scandinavica, 24, 813-833. 

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