Lignins, 3-0-4 linkage

In this paper, the molecular shape and micelle or aggregate formation of LCC molecules, the nature of the sugar-lignin linkage, and the molecular weights of LCC s will be documented on chemical or physicochemical grounds. 

Fig 6 5.2. Cleavage patterns in the hydrogenolvsis of interunitary lignin linkages... 

Although the approximate contents of major lignin linkages are now reasonably well understood [23,277], the chemical structure of lignin, unlike cellulose or hemicellulose, still cannot be precisely defined. Since carbon-carbon... 

Figure 9.15 Statistical scheme of the glucomannan-linked lignin from spruce. The structure contains 25 phenylpro-pane units with a total of 4 free phenolic hydroxyl groups. The proportion of inter-unit lignin linkages is 12 P-0-4 (2 in dibenzodioxocin), 5 P-5, 4 5-5 (2 in dibenzodioxocin), 1 4-0-5, 1 p—P, 1 P-1, 1 coniferaldehyde, 1 coniferyl alcohol.

The types and frequencies of several prominent interunitary lignin linkages are summarized in Table 1. 

Effect of lignin linkages with other plant cell wall components on in vitro and in vivo NDF digestibility of forages and potential energy yield... 

Figure 7 Schematic representation of lignin including syringul (S), guaiacyl (G), and p-hydroxyphenyl (H) phenylpropanoid moieties, and lignin—lignin linkages. Adapted from Lupoi et...

Table 1. Types and Frequencies of Interunitary Linkages in Softwood and Hardwood Lignins (Number of Linkages per 100 Units)...

Proton and carbon-13 nmr spectroscopy provides detailed information on all types of hydrogen and carbon atoms, thus enabling identification of functional groups and types of linkages ia the lignin stmcture. Detailed a ssignments of signals ia proton and carbon-13 nmr spectra have been pubHshed... 

Karhunen, P Rummakko, P. Sipila, J. Brunow, G. Kilpelainen, I. Dibenzo- dioxocins a novel type of linkage in softwood lignins. Tetrahedron Lett. 1995, 36, 169-170. 

Hatfield, R. D. Vermerris, W. Lignin formation in plants. The dilemma of linkage specificity. Plant Physiol. 2001, 126, 1351-1357. 

Sasaki, S. Nishida, T. Tsutsumi, Y. Kondo, R. Lignin dehydrogenative polymerization mechanism a poplar cell wall peroxidase directly oxidizes polymer lignin and produces in vitro dehydrogenative polymer rich in P-O-4 linkage. FEBS Lett. 2004, 562, 197-201. 

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