Lignin derivatives

A similar strategy consists in the liquefaction of biomass with phenol under acidic conditions to obtain phenolic monomers. The type of monomers obtained vary greatly (Lin et al, 2001). These monomers can be reticulated with the help of temperature and formaldehyde to obtain novolac- or resol-type resins. 

To our knowledge, none of these biomaterials has shown significant biodegradability. 

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Applications. These materials are stiU in developmental infancy. Current production is limited to one commercial process in Europe and a demonstration-scale process in North America. The lignins produced in these processes have potential appHcation in wood adhesives, as flame retardants (qv), as slow-release agents for agricultural and pharmaceutical products, as surfactants (qv), as antioxidants (qv), as asphalt extenders, and as a raw material source for lignin-derived chemicals. 

Tsutsuki, K. and Kondo, R. (1995). Lignin-derived phenolic compounds in different types of peat profiles in Hokkaido, Japan. Soil Science and Plant Nutrition 41 515-527. 

A Comparison of Lignins Derived from Various Woods. J. chem. Soc. 127, 132 (1925). 

Camarero S, Ibarra D, Martinez MJ, Martinez AT (2005) Lignin-derived compounds as efficient laccase mediators for decolorization of different types of recalcitrant dyes. Appl Environ Microbiol 71(4) 1775-1784... 

In addition to the normally suggested, sample pre-treatment procedures used prior to l.c. injection to avoid column contamination, Cig bonded silica-gel cartridges are particularly useful for removal of lignin-derived degradation-products that occur in biomass-conversion samples. 

Three laccase preparations (I, II and III) were isolated from the racellular culture medium of Coriolus versicolor by consecutive fractionation through Sephadex G50 and DEAE Sephadex A25 (84). The laccase III preparation at pH 4.0 reduced the apparent molecular weight of a lignin-derived fraction that had been obtained by eluting the water-soluble extract of a cellulase treated ezomatsu wood residue through... 

Anaerobic biodegradabUity of the components in various effluents (lignin derivatives, resin and fatty acids are known to be highly resistant to anaerobic degradation). 

Survival of Lignin-Derived Structural Units in Ancient Coalified Wood Samples... 

Lignin-derived compounds have been observed in pyrolysis products of low rank coals and associate woody tissue FI- 61. Mycke and Michaelis [2] isolated lignin-derived methoxyphenols from a Miocene coal by catalytic hydrogenolysis. Sigleo [S] reported the presence of phenolic compounds derived from iteration of lignin in pyrolysis products of silicified woody tissue as old as Triassic age. However,... 

In an attempt to delineate the degree of preservation of lignin in pre-Tertiary coal, we examined numerous coalified wood samples ranging in age from Carboniferous to Cretaceous. The samples were initially screened by solid-state l C nuclear magnetic resonance to detect the possible presence of methoxyl carbon. Once such carbons were detected, the samples were subjected to analytical pyrolysis to determine the relative yields of methoxyphenols which would provide an indication of the state of preservation of the lignin-derived structu units. We report here on the identification of lignin-derived methoxyphenols in the coalified wood samples selected for analytical pyrolysis. 

HATCHER LERCH Lignin-Derived Structural Units... 

Table III. Relative Numbers of Methoxyl and Side-Chain Carbons to Gua-iacyl Ring Carbons in Various Lignin Derivatives Isolated from Pinus thun-bergii (25,26)...

As can be seen from Fig 2b, the solid state C-13 nmr spectrum of T. aestivum also shows sets of enhanced resonances at 61 ppm and 169.6-174.9 ppm respectively (24). However, their relative intensities are very different from that observed for L. leucocephala. Indeed, it can immediately be seen that very little reduction of the administered precursor to hydroxymethyl analogues (at 61 ppm) has occurred. On the other hand, the dominant resonances at 169.6 and 174.9 ppm are coincident with bound hydroxycin-namic acids (e.g. ferulic 5a) and its esters (31). Subsequent analysis of its isolated acetal lignin derivative (32) indicated that much of the lignin contained hydroxycinnamate residues (33). 

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