Lignin-carbohydrate linkage

Wood cell wall, 21 4 cellulose in, 21 5-8 chemical composition of, 21 5-16 hemicelluloses in, 21 8-10 lignin-carbohydrate linkages in, 22 14-15... 

Lundquist K, Simonson R, Tingsvik K (1980) Studies on lignin carbohydrate linkages in milled wood lignin preparations Sven Papperstidn 83 452-454... 

The phenolic hydroxyl and etherified benzyl alcohol group can be selectively oxidized by periodate [385] and 2,3-dichloro-5,6-dicyano-l, 4-benzoquinone (DDQ) [386], respectively. The periodate oxidation of guaiacyl and syringyl nuclei yields 0-quinones plus methanol and has been used to estimate the phenolic hydroxyl group content of lignin. DDQ oxidation has been applied to estimate the content of lignin-carbohydrate linkages [28]. 

Balakshin, M. Y, Capanema, E. A., and Chang, H. M. (2007) MWL fraction with a high concentration of lignin-carbohydrate linkages Isolation and 2D NMR spectroscopic analysis. Holzforschung 61(1), 1-7. 

BO Lindgren. The lignin-carbohydrate linkage. Acta Chem Scand 12 447-452, 1958. 

K Lundquist, R Simonson, K Tingsvik. Lignin carbohydrate linkages in milled wood lignin preparations from spruce wood. Sven Papperstidn 86 R44-R47, 1983. 

Proper extraction process needs special requirements to fractionate a certain hemicellulose or mixture of hemicelluloses. However, the presence of lignin network as well as ester and ether lignin-carbohydrate linkages limits the hemicellulose extraction... 

The extraction of the wood residue with dimethylsulfoxide (DMSO) after extraction of MWL produces Bjorkman s LCC [23] which has been considered for a long time as the classical and unique LCC preparation. Other solvents and water were also used to extract LCC preparations from the residue obtained after MWL isolation [17-19,35]. The concentration of lignin-carbohydrate linkages by enzymatic hydrolysis of the carbohydrate components of the DMSO-extracted LCC preparations [36] is a useful approach for LCC linkages analysis. 

The MWEL is a very representative preparation to study ether lignin-carbohydrate linkages in wood since it would appear that it contains all of the original ether linkages [20]. Therefore, it is very appropriate to study the ether LCC linkages with the help of wet chemistry methods, such as meth-ylation and DDQ degradative techniques. However, in contrast to the CEL, the MWEL is not completely soluble in NMR solvents, and therefore its analysis by high-resolution spectroscopic methods is not viable. 

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