NC State
Nie, X. N., Liu, J., She, D., Sun, R. C., and Xu, F. (2013). "Physicochemical and structural characterization of hemicelluloses isolated by different alcohols from rice straw," BioRes. 8(3), 3817-3832.


Six alcohol-soluble hemicellulosic preparations from rice straw were comparatively studied, and their physicochemical characterizations were examined. The treatments of the dewaxed rice straw with 60% methanol, 60% ethanol, 60% n-propanol, 60% n-butanol, 60% ethanol containing 0.01 M HCl, and 60% ethanol containing 0.25 M NaOH at 75 ºC for 3 h were able to solubilize 10.4, 10.4, 6.2, 6.5, 7.4, and 55.0% of the original hemicelluloses, respectively. The results showed that methanol and ethanol had similar solubilization capacity of hemicelluloses and gave slightly higher solubility compared to n-propanol and n-butanol. The major monosaccharide of the four neutral alcohol-soluble hemicellulosic fractions was xylose (31.78-36.80%) followed by glucose (26.35-39.39%), galactose (15.05-17.17%), and arabinose (14.93-15.58%), whereas the alkaline ethanol-soluble hemicellulosic fraction contained the highest amount of xylose (59.62%). By combining 1H, 13C, and 2D-HSQC NMR with FT-IR spectroscopy, the alkaline ethanol-soluble hemicellulosic fraction can be structurally defined as 4-O-methyl-α-D-glucurono-L-arabino-D-xylans.
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