Saccharification, of wood

The two most important natural pentoses, 1 -arabinose and 1 -xylose, occur in nature as polymeric anhydrides, the so-called pentosans, viz. araban, the chief constituent of many vegetable gums (cherry gum, gum arabic, bran gum), and xylan, in wood. From these pentapolyoses there are produced by hydrolysis first the simple pentoses which are then converted by sufficiently strong acids into furfural. This aldehyde is thus also produced as a by-product in the saccharification of wood (cellulose) by dilute acids. Furfural, being a tertiary aldehyde, is very similar to benzaldehyde, and like the latter undergoes the acyloin reaction (furoin) and takes part in the Perkin synthesis. It also resembles benzaldehyde in its reaction with ammonia (p. 215). 

E. E. Harris, Saccharification of Wood, Forest Products Lab. Rept. No. R1476, March, 1945. 

Enzymatic Hydrolysis. Saccharification of wood polysaccharides to sugars can be accomplished by enzymatic techniques instead of acid hydrolysis. The U.S. Army Natick Laboratories developed a method for conversion of cellulose to glucose with a cellulose enzyme from an active strain of the fungus Trichoderma viride. However, extensive pretreatment of wood is necessary before sufficient enzymatic hydrolysis will take place. 

Scholler saccharification process. Industrial saccharification of wood using 0.5% sulfuric acid at 170-180 degrees and 165-180 lb/sq inch pressures. Recovered sugars are fermented to produce about 40 gal alcohol per ton of dry wood. 

Saccharification, of wood, 4, 153-188 Saccharinic acids, 12, 35-79 fom-carbon, 13, 169-188 Schardinger dextrins, 12, 189-260 Seaweeds,... 

C, [ago -75°- -19 (H O) p-DL-xylo-pyranose, OL-form, mp. 129 -131 °C. The L-forms are not natural. An aqueous solution of X. at, e.g., 31 °C, contains 36.5% a-pyranose, 63% )S-pyranose, <1% a-and /3-furanose, and 0.02% aldehyde. X. is obtained technically from the saccharification of wood and from the residues of cellulose production or, respectively, by isolation from xylans or from ears of corn by hydrolysis with dilute acids. Reduction of X. furnishes xylitol which can be used as a sugar substitute. X. itself would also be suitable for use as a sweetener but has only half the sweetness of saccharose and also shows laxative effects. 

Cellulose an unbranched plant polysaccharide, M, 300,000-500,000, consisting of pi,4-linked glucose units. C. is enzymatically hydrolysed to the disaccharide cellobiose. It can be hydrolysed to D-glucose by treatment with concentrated acids, such as 40% HCl or 60-70 % H2SO4 at high temperature. This process, called saccharification of wood, is used to produce fermentable sugar from wood. 

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