Sugar acids, column chromatography

In addition to classical reverse phase separation of peptides on octadecyl derivatized silica monoliths, sugars and peptides as well as proteins and nucleosides have been analyzed on a 20-cm-long silica-based poly(acrylic acid) column (ID. 200 pm), employing HILIC and weak cation-exchange chromatography, respectively [194]. Furthermore, HILIC fractionation of polysaccharides delivered remarkable and promising results [84,194]. 

From the known, differential complexing between boronic acids and polyhydroxy compounds, it follows that carbohydrate mixtures may be separated by column-chromatographic methods that exploit the differences. Nucleoside and nucleotide boronates have been separated on columns of anion-exchange resins,90 and sugars and alditols have been shown to be differentially retained on such resins in the sulfonated phenylboronic acid form,64 but perhaps the best uses of column chromatography in this connection have incorporated the resolving powers of insoluble polymers to which boronic acid groups have been covalently bonded. Such insoluble forms of boronates have been synthesized either by substitution of polysaccharide derivatives, or by polymerization of suitable arylboronic acids. 

II. Adsorbents for the Column Chromatography of Sugars, Sugar Alcohols, and Sugar Acids... 

Table XVI (see p. 56) lists those polysaccharides whose structures have been examined by using the methylation technique and the methylated sugars have been separated as their methyl glycosides. In a few studies, g.l.c. has been used only to check on the identity of fractions separated by column chromatography. For convenience. Table XVI is subdivided according to the type of polysaccharide involved. In a similar way, Tables XVII (see p. 72), XVIII (see p. 76), and XIX (see p. 79) list those neutral, acidic, and basic oligosaccharides whose structures have been investigated in like manner by using g.l.c. Typical retention-times have been tabulated. ...

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