Sorghum grain structure

A number of sub-fractions have been isolated from the hemicellulose B fraction of the husks of Sorghum grain. Three of these sub-fractions were each found to contain residues of L-arabinose, D-xylose, D-galactose, D-glucose, and D-glucuronic acid and its 4-0-methyl ether. Structural studies confirmed that the three polysaccharides were xylans with the usual )8-l,4-linked main chain. There were considerable differences in the D.P. of these polysaccharides, the values obtained being 993, 2380, and 851. 

The glucuronoarabinoxylan from sorghum-grain husks is composed of L-arabinose, D-xylose, D-glucuronic acid, and 4-0-methyl-D-glucuronic acid (15 18 2 1). Structural studies indicated that the polysaccharide has a main chain of (1 4)-linked jS-D-xylopyranosyl residues, with the uronic acid... 

Wong, J. H., T. Lau, N. Cai, J. Singh, J. E Pederson, W. H. Vensel, W. J. Hurkman, J. D. Wilson, P. G. Lemaux, and B. B. Buchanan. 2009. Digestibility of protein and starch from sorghum Sorghum bicolor) is linked to biochemical and structural features of grain endosperm. Journal of Cereal Science 49 73-82. 

C. A possible structure of grain sorghum condensed tannin. 

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