Isolation and Characterization of Hemicelluloses Polysaccharides of Scots Pine Wood (Pinus Sylvestris)

Abstract

Many natural polysaccharides have biological activity, which allows them to be used to obtain medicines. The development of new methods for the isolation of polysaccharides from plant materials, as well as the study of their properties and structure, is an actual task. In this work the polysaccharide galactoglucomannan (GGM) was isolated from pine wood time by the peroxide delignification in the “acetic acid-water” medium in the presence (NH4)6Mo7O24.Its yield was 10.1 wt.% from the weight of wood and 58.1 wt.% from the content of hemicelluloses in wood. By 13С NMR method it was found that the degree of GGM acetylation is 0.23 with substitution of carbon atoms of the pyranose ring at C2 and C3. According to the X-ray data, GGM has an amorphous supramolecular structure. The polysaccharide gluoxylan (GX) was isolated by alkaline extraction from the cellulose product obtained after peroxide delignification. Its yield was 4.3 wt.%. from wood and 24.5 wt.% from the content of hemicelluloses in wood.Glucoxylan does not contain acetyl groups (data from IR and NMR spectroscopy), it has a crystalline supramolecular structure and is poorly soluble in water. Composition and structure of the obtained polysaccharides were studied using chemical methods of analysis, IR spectroscopy, 1H, 13C, 2D HSQC NMR spectroscopy, gas chromatography, X-ray analysis.