Enzymatically liberated lignin

As can be seen, the cellulolytic action of the fungus has indeed brought about a two-fold increase in the yield of extractable lignin. The native and enzymatically liberated lignins were then chemically compared and found to be identical in all respects examined (Table 4). 

Table 5- Comparison of the Native and Enzymatically Liberated Lignins from White Scots Pine with Spruce Native Lignin (99).

Moreover, the identity of the native and enzymatically liberated lignins from this softwood is further corroborated by their ultraviolet and infrared absorption spectra (79), (99). (See page 88,92 and Fig. 1 and 5.)... 

Consequently, the native and enzymatically liberated lignins from white Scots pine, oak, birch, maple, kiri1 wood and bagasse were oxidized with nitrobenzene in alkali. The method of Stone 113) was applied quantitatively in this study. The amount of each degradation product obtained from each of the lignins is listed in Table 12 110). 

VI. Discussion of Analytical Data of Native and Enzymatically Liberated Lignins. 

This section will deal with the absorption spectra of the native and enzymatically liberated lignins from various woody tissues. With the exception of aspen native lignin, bagasse native and enzymatically liberated lignins and kiri native lignin, all the native lignins and their derivatives have one maximum at about 280 mp. Some of these results are included in Table 43. The absorption curves of some native and enzymatically liberated lignins are presented in Fig. 4. 

Ultraviolet spectroscopic studies on bagasse native lignin demonstrated that (a) the native and enzymatically liberated lignins are identical, and (b) that it has a molecular constitution somewhat different from other lignins (54), (107), (111). (See Fig. 2.)... 

Hi — — Investigations on Lignin and Lignification. XII. A Study of Lignin Formation Based on the Oxidation of Native and Enzymatically Liberated Lignins. Proc. nat. Acad. Sci. USA. 39, 80 (1953). 

In Table 6 4 3 are shown the yields of monomeric products recovered from milled wood lignin (MWL) and enzymatically liberated lignin (EL) fractions successively isolated from poplar wood and subjected to various degradation procedures (Lapierre 1986) These values reveal that acidolysis, which should allow the characterization of the same lignin structures as thioacidolysis,... 

Isolation of two trimeric compounds with lactone ring. Holzforschung 35 183-187 Yeboah SA, Wang S-H, Griffiths PR (1984) Effect of pressure on diffuse reflectance infrared spectra of compressed powders. Appl Spectrosc 38 259-264 Zavarin E, Nguyen C, Romero E (1982) Preparation of enzymatically liberated lignin from naturally brown-rotted wood. J Wood Chem Technol 2 343-37... 

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