Reversible 2-epimerization of CDP-paratose and CDP-tyvelose

Abstract

This chapter highlights that the important role of glycosyl esters of nucleoside pyrophosphates in carbohydrate metabolism is well known. The chapter deals with the metabolism of these compounds, and particularly with the synthesis of glycosides, polysaccharides, and complex carbohydrate-containing polymers. The isolation of an individual glycosyl ester of a nucleoside pyrophosphate is a rather difficult task. Ion-exchange column-chromatography and preparative, paper-chromatography have been the main methods used for solving problems in separation. The ion-exchange separation usually affords individual fractions of structurally related glycosyl esters of nucleoside pyrophosphates, containing the same nucleotide residue, but differing in the structure of the glycosyl groups. Separation of the esters of N-acetylhexosamines, uronic acids, and neutral monosaccharides from one another is also usually achieved. Preparative, paper-chromatography is frequently used for further fractionation of the resulting mixtures. The high lability of glycosyl esters of nucleoside pyrophosphates seriously limits the choice of solvent systems.