Jun 16, 2011... acetylation, and methylation reactions were analyzed. The band intensity changes depended upon the nature of the chemical treatments. ...

Received December 27, 1995X Abstract: A novel (possibly unique) lignin isolated from kenaf bast fibers had a high syringyl:guaiacyl ratio, was highly etherified, and was high in ?-ether units with predominantly erythro stereochemistry. Moreover, it was extensively side-chain acetylated (primarily at ?), implicating 4-hydroxycinnamyl acetates as monomers in ...

We describe the synthesis and NMR spectroscopic analysis of three artificial lignin polymers containing only the beta-O-4 substructure: syringyl-type homopolymer, p-hydroxyphenyl-type homopolymer and guaiacyl/syringyl-type heteropolymer. Using gel permeation chromatography, the weight-average degree of polymerization (DP(w)) of the three polymers was determined as 19.2, 38.6, ...

... kraft POM delignified pulps were isolated by mild acid hydrolysis. Analyses of the residual lignins show that during ... ...

Lignin is a renewable resource material that is being evaluated for the low cost production of carbon fiber for automotive and other applications. Solvent extraction of a commercial hardwood lignin product yielded a purified lignin free of the contaminants typical of lignins derived from the ...

Two Streptomyces strains, S. viridiosporus T7A and S. setonii 75Vi2, were grown on softwood, hardwood, and grass lignocelluloses, and lignocellulose decomposition was followed by monitoring substrate weight loss, lignin loss, and carbohydrate loss over time. Results showed that both Streptomyces strains substantially degraded both the ...

Two Streptomyces strains, S. viridosporus T7A and S. setonii 75Vi2, were grown on softwood, hardwood, and grass lignocelluloses, and lignocellulose decomposition was followed by monitoring substrate weight loss, lignin loss, and carbohydrate loss over time. Results showed that both Streptomyces strains substantially degraded both the ...

Eleven gram-negative aerobic bacteria (Pseudomonadaceae and Neisseriaceae) out of 122 soil isolates were selected for their ability to assimilate poplar dioxane lignin without a cosubstrate. Dioxane lignin and milled wood lignin degradation rates ranged between 20 and 40% of initial content after 7 days in mineral medium, as determined ...

Eleven gram-negative aerobic bacteria (Pseudomonadaceae and Neisseriaceae) out of 122 soil isolates were selected for their ability to assimilate poplar dioxane lignin without a cosubstrate. Dioxane lignin and milled wood lignin degradation rates ranged between 20 and 40% of initial content after 7 days in mineral medium, as determined ...

There is little information available on the variation in lignin content of growth rings in hardwoods. This study examines whether infrared microscopy can detect intra-incremental differences in the chemical composition of three hardwoods (R. pseudoacacia, P. Americana, and G. triacanthos) and the effect of such differences on the ...

Pyrolysis, GC and mass spectrometry were performed on milled wood lignins and wood samples. Among the major pyrolysis products identified from loblolly pine lignin were: guaiacol, 4-methylguaiacol, 4-vinylguaiacol, vanillin, coniferaldehyde and coniferyl alcohol. White oak lignin pyrolysis products included: guaiacol, 4-methylguaiacol, ...

The primary objective of this research is the isolation and identification of microbes, which are ectosymbiotes of wood-inhabiting insects, which degrade native hardwood lignins into substances including appetite stimulants. Thus far the hardwood substrat...

A feasibility study was conducted to assess the utilization of lignin, isolated from a steam-exploded hardwood (Tulip poplar) with 95% ethanol and 0.1n NaOH, as a potential adsorbent for hazardous waste treatment. Eight organic compounds and two heavy met...

The results of investigations of the topological and supramolecular structures of lignins are considered. The experimental data on the hydrodynamic and conformational properties of dilute solutions of hardwood and softwood lignins are generalised. The relationship between hydrodynamic and fractal properties of ...

Jun 16, 2011 ... Keywords: Wood chemistry, Chemical composition, Lignocellulose, Spectroscopy, Spectral analysis, Bleaching, Hydrogenation, Acetylation, ...

which depolymerizes lignin and polyphenols; N-acetyl-glucosaminidase which hydrolyzes chitin metabolites extracellular enzymes capable of degrading lignin, cellulose, and organic N, which are dominant components

Project Objective: Our long-term goal is to genetically engineer higher value raw materials with desirable wood properties to promote energy efficiency, international competitiveness, and environmental responsiveness of the U.S. forest products industry. The immediate goal of this project was to produce the first higher value softwood raw materials engineered with a wide range of syringyl ...

A nongravimetric acetyl bromide lignin (ABL) method was evaluated to quantify lignin concentration in a variety of plant materials. The traditional approach to lignin quantification required extraction of lignin with acidic dioxane and its isolation from each plant sample to construct a ...

The analytic composition of red alder wood and wheat straw, and their cellulose, hemicellulose, lignin, and extractive components are summarized. An enzyme mechanism is proposed to explain the reddish orange darkening of red alder chips when exposed to air. The discovery of the catalytic effect of aluminum salts upon the organic solvent delignification of ...

Our previous studies have shown that hypergravity inhibits growth and promotes lignin forma-tion in inflorescence stems of Arabidopsis thaliana by up-regulation of genes involved in lignin biosynthesis (Tamaoki et al. 2006, 2009). In the present study, we have examined whether ethylene is involved in these responses using an ethylene-insensitive ...

Pretreatment of hardwood biomass with supercritical ammonia dramatically enhances the susceptibility of the substrate to enzymic hydrolysis. The pretreatment of both hardwoods and softwoods increases the substrate nitrogen content via amidation reactions and increases total pore volume without increasing maximum pore width. Pretreatment does not ...

Hardwood 4-O-methylglucuronoxylans (MGX) are classically isolated by a delignification step, using a sodium chlorite solution, followed by alkaline extraction, an efficient, although potentially polluting process. In this work, we propose a chlorine-free environmentally-friendly process for MGX extraction from Castanea sativa Mill. Chestnut sawdust was first delignified using ...

degradation of leaf litter to produce more DOC and less CO2, especially if rates of lignin depolymerization, regardless of the form, can suppress the decomposition of plant detritus that is high in lignin and low in N). In contrast, N applied to relatively low-lignin, high-N litter can stimulate decomposition (Carreiro

The degree of polymerization (DP) of softwood and hardwood milled wood lignin samples and their branching were quantitatively evaluated by a novel end group titration approach using QQ-HSQC, 31P-NMR and DFRC coupled with 31P-NMR analysis techniques. The DP of lignin can be calculated when the C9 formula, the quantitative amount of ...

A series of non-wood plant fibers, namely kenaf, jute, sisal and abaca, have been analyzed upon pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) of the whole material. The pyrolysis products mainly arise from the carbohydrate and lignin moieties of the fibers. The lignin-derived phenols belonged to the p-hydroxyphenylpropanoid (H), ...

Lignin in plant cell wall is a source of useful chemicals and also the major barrier for saccharification of lignocellulosic biomass for producing biofuel and bioproducts. Enzymatic lignin degradation/modification process could bypass the need for chemical pretreatment and thereby facilitate bioprocess consolidation. Herein, we reveal our new discovery in ...

Lignin concentration can be measured in plants by the acetyl bromide-soluble lignin spectrophotometric method; however, as with any spectrophotometric method, a reliable standard is needed. In the present experiments, lignin was extracted from each of the forages under study with the acetyl ...

Specifically radiolabeled (/sup 14/C-lignin)lignocelluloses and (/sup 14/C-polysaccharide)lignocelluloses were prepared from a variety of marine and freshwater wetland plants including a grass, a sedge, a rush, and a hardwood. These (/sup 14/C)lignocellulose preparations and synthetic (/sup 14/C)lignin were incubated anaerobically with ...

Specifically radiolabeled [¹⁴C-lignin]lignocelluloses and [¹⁴C-polysaccharide]lignocelluloses were prepared from a variety of marine and freshwater wetland plants including a grass, a sedge, a rush, and a hardwood. These [¹⁴C]lignocellulose preparations and synthetic ...

In order to gain information about lignin molecular characteristics with a direct bearing on the remarkable susceptibility of some Austral hardwoods to biological delignification, milled-wood lignins were isolated and analyzed by spectroscopic techniques in the solid state. Cross polarization and magic-angle spinning 13C nuclear ...

This paper deals with the photobleaching of acetylated wood. The acetylated spruce wood was irradiated by artificial sunlight emitted from xenon lamp with covering several kinds of band-pass filter. The lightness (L(*)) of acetylated wood increased with integral irradiance. The chroma (?C(*)) decreased by light-irradiation with ...

Quick quantitative HSQC (QQ-HSQC) was applied to quantitative evaluation of different inter-unit linkages in an array of milled softwood and hardwood and technical lignins by using the guaiacyl C2 and syringyl C2-C6 signals as internal standards. The results were found to be highly reproducible and comparable with earlier literature reports. The advantage ...

Research accomplishments during the latter phases of a three-part program to utilize biomass material are reported. Methods of delignification and characterization of by-product lignins and conversion processes of biomass components to chemical feedstocks are described. The former involves catalyzed pulping of hardwood and bagase, and the isolation and ...

Research demonstrated that a Basidiomycete fungus, Irpex lacteus, isolated from active galleries of the beetle Xyloterinus politus in Quercus (oak) trees, degraded approximately five times as much lignin from the standard hardwood substrate, No. 002 wood,...

The electrochemical conversion of biomass-derived compounds, obtained through thermochemical pretreatments, into valuable organic chemicals, petrochemical substitutes, and energy-intensive chemicals is investigated. A hardwood-derived lignin obtained from...

The mechanism of delignification of hardwoods by 'neutral' (moderately alkaline) sulphite solutions has been studied by considering the reactions of appropriate lignin model compounds, the influence of pulping conditions, particularly time and temperature...

This appendix volume contains papers on the following topics: the associative effects among organosolv lignin components; the effect of heating and quenching rates on volatiles produced from combustion-level-heat-flux pyrolysis of biomass; and the effect ...

The analytic composition of red alder wood and wheat straw, and their cellulose, hemicellulose, lignin, and extractive components are summarized. An enzyme mechanism is proposed to explain the reddish orange darkening of red alder chips when exposed to ai...

The conversion of the wood components--cellulose, hemicelluloses, and lignin--from low-quality southern hardwoods to useful chemicals in a systematic integrated manner was examined. Specific objectives included prehydrolysis of the hemicelluloses for opti...

This study examines the conversion of hemicellulsoe, cellulose, and lignin from low-quality southern hardwoods to useful chemicals in a systematic integrated manner. Specific objectives include prehydrolysis of the hemicelluloses for optimum conversion to...

Progress is reported on the project to convert hemicelluloses, lignin, and cellulose from low-quality southern hardwoods into useful chemicals in a systematic, integrated manner. Specific objectives include prehydrolysis of hemicelluloses for optimum conv...

This project studies the conversion of the wood components (hemicelluloses, cellulose, and lignin) from low-quality southern hardwoods to useful chemicals in a systematic integrated manner. Specific objectives include prehydrolysis of the hemicelluloses f...

A cDNA clone encoding the lignin-related enzyme caffeoyl?CoA 3-O-methyltransferase (CCoAOMT) was isolated from a Pinus radiata cDNA library derived from differentiating xylem. Suppression of PrCCoAOMT expression in P.�radiata tracheary element cultures affected lignin content and composition, resulting in a lignin polymer containing ...

About 100 individual organic compounds were determined in urban aerosols collected at Gent, Belgium. The compounds were identified by gas chromatography-mass spectrometry, and quantitative data were obtained by gas chromatography-flame ionization detection. Measurements of the particulate mass and of organic and elemental carbon mass were also made. Aerosol samples from a winter and a summer ...

To characterize the lignin structures and lignin-carbohydrate complex (LCC) linkages, milled wood lignin (MWL) and mild acidolysis lignin (MAL) with a high content of associated carbohydrates were sequentially isolated from ball-milled poplar wood. Quantification of their structural features has been achieved by ...

The surface energy of lignin films spin-coated onto oxidized silicon wafer has been determined from contact angle measurements of different test liquids with varying polar and dispersive components. Three different lignin raw materials were used, a kraft lignin from softwood, along with milled wood lignin from ...

In the present study, a steam explosion wood pre-treatment process, optimized earlier with respect to ethanol production, has been applied to both softwoods (Picea abies and Pinus sylvestris) and hardwoods (Betula verrucosa and Populus tremula). The alkaline extractable lignins have then been isolated to investigate lignin separation ...

A feasibility study was conducted to assess the utilization of lignin, isolated from a steam-exploded hardwood (Tulip poplar) with 95% ethanol and 0.1n NaOH, as a potential adsorbent for hazardous waste treatment. Eight organic compounds and two heavy metals were selected to allo...

This research is to explore conditions under which the lignin-rich residue from TVA's two stage hardwood based wood saccharification pilot plant can be used as a prepolymer for phenol-formaldehyde resin products and other thermosetting plastics. Six speci...

An ionic liquid, 1-butyl-3-methylimidazolium chloride ([Bmim]Cl), was used to dissolve Japanese fir (Abies sachallnensis MAST) wood. Milled woods prepared by planetary ball-milling for 8 h dissolved completely in [Bmim]Cl at 100 �C in 2 h. The dissolved woods were then subjected to in situ acetylation, and the fully acetylated woods were regenerated from ...

It is steadily being recognized that plant lignin structure can no longer be adequately represented by synthetic preparations, obtained by treatment of the monolignols with peroxidase H{sub 2}O{sub 2} in vitro. Indeed, differences in lignin composition and structure between species, tissues, and even subcellular locations indicate that a highly ...

Lignins derived from abundant and renewable resources are nontoxic and extremely versatile in performance, qualities that have made them increasingly important in many industrial applications. We have shown recently that liquefaction of lignin extracted from aspen wood resulted in a 90% yield of liquid. In this paper, the hydrothermal treatment of five ...

Lignins derived from abundant and renewable resources are nontoxic and extremely versatile in performance, qualities that have made them increasingly important in many industrial applications. We have shown recently that liquefaction of lignin extracted from aspen wood resulted in a 90% yield of liquid. In this paper, the hydrothermal treatment of five ...

To produce ethanol from hardwood it is desirable to fractionate the hardwood in order to produce a relatively pure cellulosic pulp for dilute acid hydrolysis. An experimental investigation of continuous steam hydrolysis of tulip poplar wood chips indicates that over 90% of the lignin present can be extracted by 0.1N sodium hydroxide, ...