Alginic acid, hydrolysis

The Structure of Alginic Acid. Part V. Isolation and Unambiguous Characterization of Some Hydrolysis Products of the Methylated Polysaccharide, Sir Edmund Hirst and D. A. Rees, J. Chem. Soc., 1182 (1965). 

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 °< ... 

Depolymerization of Alginic Acid. Alginic acid depolymerization is a process that removes the MG blocks by cleaving the MG glycosidic bond which is more susceptible to acid hydrolysis than the glycosidic bonds in homopolymeric blocks. The resulting solid is a mixture of the two homopolymeric GG blocks and MM blocks. The method used was a modification of the procedure described by Penman and Sanderson (10). 

Depolymerized Alginic Acid Solution NMR Studies. Studies are being conducted with depolymerized alginic acid. In these samples, the MG blocks were removed by acid hydrolysis lea dng shorter chains contmning mostly GG or MM blocks. For whole alginic acid, complexation of one ion to a GG block leads to a zipper effect. If two or more metal ions bind to GG blocks that are separated by one... 

Improvements were made by Frush and Isbell (79) in the sulfuric acid-hydrolysis method of isolating mannuronic acid lactone from alginic acid. Spoehr (236) reported a new method for the isolation of the lactone depending on hydrolysis with formic acid. The authors have found that the formic acid method, with modifications, is adaptable to the production of mannuronic acid lactone. 

Q, How does one get a good yield of mannuronic acid lactone from alginic acid using the Spoehr procedure, which I believe employs formic add for hydrolysis Is alginic acid stable under acid treatment ... 

Formed by the partial acid hydrolysis of a chemically reacted alginic acid, extracted from Laminaria digitata. Cryst. (EtOH/ EtOAc). 

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