UBC Theses and Dissertations
Constitution of the hemicelluloses of corn leaves and corn stalks. Kabir, Mohammad Shahjahan
Fractionation of the polysaccharides from corn leaves by extraction with dilute alkali furnishes a branched chain arabinoxylan containing D-glucuronic acid, small amounts of 4-O-methyl-D-glucuronic acid and D-glucose. Complete acid hydrolysis of the periodate oxidised polysaccharide gives ethylene glycol, glycerol, erythritol and D-xylose in a molar ratio of 1:34:8:18. Hydrolysis of the methylated hemicellulose has yielded a mixture of 2-O- and 3-O-methyl-D-xylose; 2,3-di-O-methyl-D-xylose; 2,3,4-tri-O-methyl-D-xylose; 2,3,5-tri-O-methyl-L-arabinose and 2-O-(2,3,4-tri-O-methyl-α-D-glucopyranosyluronic acid)-3-O-methyl-D-xylose in a molar ratio of 4.6:3:40:1:4.5:6. The side chains of the polysaccharide consist of single units of uronic acid and single units of L-arabofuranose joined to positions 2 and 3, respectively, of D-xylo-pyranose units of the xylan molecular framework. A similar polysaccharide is present in corn stalks. The variety used was Golden Bantam.
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