Preparation, isolation, and characterization of permethylated galactosides and fucosides

Sugar analysis involving permethylation followed by methanolysis can lead to significant results, given that permethylated monosaccharide standards are available for comparison of spectral and chromatographic data. Such standards are not readily commercially available, especially the furanoside forms. This note describes the isolation and characterization of permethylated pyranoside and furanoside species of D(+)-galactose and L(-)-fucose. Separation of the isomers was optimized using a combination of column chromatography and continuous elution thin-layer chromatography (TLC). TLC, gas chromatography - mass spectrometry, and H-1 nuclear magnetic resonance (NMR) spectroscopy were used as the characterization methods. The isolation of furanosides is emphasized, since no specific NMR data have been reported on those to date, while several reports have already discussed the structural aspects of pyranosides.