Glycosides methyl, acetates, chromatography

Figure 16.5 Affinity chromatography of peroxidase (after A. Borchert, P.O. Larsson and K. Mosbach, J. Chromatogr., 244, 49 (1982)]. Conditions sample, 4.1 ml of solution with 1 pg ml of protein column, 5cm x 5 mm i.d. stationary phase, concanavalin A on LiChrospher Si 1000, 10pm mobile phase, 0.05M sodium acetate, 0.5 M sodium chloride, 1 mM calcium chloride, 1 mM manganese chloride, pH 5.1 t shows pulse of 4.1 ml of 25 mM a-methyl-o-glycoside detector, solid line, UV, 280 nm broken line, visible, 405nm. Peaks = nonretained proteins this peak contains less than 2% peroxidase 2 = peroxidase.

Using the Guthrie-Smith acetolysis of the methyl glycosides, all eight a- and 3-D-aldopentofuranose tetra-acetates have been synthesized all were separated, except the a, S-D-arabinoses, and characterized by H and C n.m.r. When the same reaction was applied to methyl 2,3,5-tri-O-benzoyl-a-D-arabinofuranoside, the anomeric TO-acetyI-2,3,5-tri-( -benzoyl-D-arabinoses were separable by chromatography on silica gel. ... 

Samples (2 mg) of the proteins were methanolyzed with methanol-1.5 M HCl and N-acetylated with acetic anhydride (19). The determination of methyl glycosides as their trimethylsilyl ethers was carried out by gas-liquid chromatography (20). 

The synthesis of all the methyl mono-O-acetyl- - and - -D-xylo-pyranosides has been achieved by unimolecular acetylation of methyl mono-O-benzyl-D-xylopyranosides, followed by chromatographic fractionation and debenzylation. The three methyl di-O-acetyl-o -D-xylopyranosides were also obtained. Separation by liquid chromatography of the mixtures obtained by acetylation of a tri-O-methyl fraction from partial methylation of methyl ot-D-glucopyranoside gave all possible mono-O-acetyl-tri-O-methyl glycosides. Acetylation of D-xylose with acetic anhydride in... 

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