Straw hemicelluloses

FTIR spectra of extracted wheat straw hemicellulose and cellulose do not exhibit this band (spectra not shown). From this point, the extracted wheat straw XRPP is also assigned to pectic substances. The intensity ratio of the bands i>as(COO ) at 1608 cm" and j (C 0) ester at 1740 cm corresponds to fully deesterified pectin and Me pectate... 

However, oral administration of these polysaccharides had no effect. Hemi-celluloses from different higher plants caused regression of solid Sarkoma 180 in mice but not of ascites tumor. Arabinoglucuronoxylan isolated from wheat-straw hemicellulose was completely devoid of activity, whereas arabinoglucoxylan was highly active (Nakahara 31)). 

Garde, A., Jonsson, G., Schmidt, A. S., and Ahring, B. K. 2002. Lactic acid production from wheat straw hemicellulose hydrolysate by Lactobacillus pentosus and Lactobacillus brevis. Bioresour. Technol., 81,217-223. 

The xylanase produced by Agaricus bisporus158 degraded rice-straw hemicellulose, initially to L-arabinose and the xylo-oligosaccharides of d.p. 3= 2. D-Xylose was liberated upon prolonged hydrolysis. 

Fig. 5 FTIR spectra of commercial xylan from birch wood (line 1) and FTIR spectra of wheat straw hemicellulose extracted with 0.25 mol/1 NaOH/30 °C (tine 2), 0.50 mol/1 NaOH/30 °C (line 3), 0.25 mol/ 1 NaOH/55 °C (line 4), and 0.50 mol/1 NaOH/55 °C (line 5) all the treatments for 2 h...

Nigam, J. N. (2001). Ethanol production from wheat straw hemicellulose hydrolysate by Pichia stipitis. Journal of Biotechnology, 87, 17—27. 

Figure 9.9 TG curves of wheat straw and its components in a dynamic Nj atmosphere. I, wheat straw II, wheat straw holocellulose III, wheat straw hemicellulose IV, wheat straw lignin...

Attempts have been made to characterize the rice-straw hemicelluloses that may act as binding constituents in the manufacture of paper. ... 

Wheat straw hemicellulose stearates were synthesized in DMF/LiCl by using 1-3 eq. acid chloride in the presence of triethylamine or pyridine and DMAP (4). DS values between 0.18 and 1.71 were obtained depending on the reaction conditions. A maximum DS of 1.71 was realized with 3 eq. acylating reagent after 30 min at 75°C. It was found that the polymer degradation is lower than 8% at short reaction times and temperatures below 75 C. A notable degradation occurs during the acylation at 85 C. 

The conversion of water-soluble wheat straw hemicellulose with succinic anhydride in aqueous alkaline solutions yields carboxyl groups containing products (6). The DS values of the products are rather low (<0.26) due to side-reactions in the aqueous medium. Despite the low functionalization, the thermal stability is increased and applications as thickening agents and metal ion binders are proposed. 

Sun, Runcang Sun, X. F. Bing, X. Succinoylation of Wheat Straw Hemicelluloses with a Low Degree of Substitution in Aqueous Systems. J. Appl Polym. Sci. 2002, 83, 757-766. 

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