SELECTIVE DEGRADATION OF THE GLYCOSYLURONIC ACID RESIDUES OF COMPLEX CARBOHYDRATES BY LITHIUM DISSOLVED IN ETHYLENEDIAMINE

Article abstract of DOI:10.1016/0008-6215(87)80028-9

Lithium metal dissolved in ethylenediamine had been demonstrated to cleave a 3-linked glycosyluronic acid-containing polysaccharide .The present study with model compounds has established that, by lithium treatment, carbohydrates are cleaved at the sites of the glycosyluronic acid residues, regerdless of the point at which other glycosyl residues are attached to the glycosyluronic acid residue.Treatment of carbohydrates with lithium metal dissolved in ethylenediamine also results in cleavage of methyl glycosides, reduction of aldoses, and cleavage of methyl ethers and pyruvic acetals of glycosyl residues.Model compounds were used to demonstrate that oligosaccharides containing only neutral glycosyl residues are largely stable to the reaction conditions (except for the reduction of the glycose residue of each oligosaccharide).Thus, a general procedure for the selective cleavage of underivatized carbohydrates at the glycosyluronic acid residues is described.