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Lignocresol was isolated from softwood with p-cresol using sulfuric acid and phase separation. An alkaline treatment of the lignocresol, followed by acidification, selectively yielded a guaiacyl coumaran, G1, in the acid-soluble fraction. With further alkaline treatment of G1 in 0.5 M of NaOH solution at 170 °C for 60 min, it was strongly suggested that a guaiacyl benzofuran derivative, G2, was obtained by the elimination of formaldehyde, based on analytical data of the reaction mixture. The process is very unique and well-designed based on the reactivity of Cα-ethers, or Cα-OH, Cβ-aryl-ethers, and Cγ-OH of lignin, although condensation reactions via formaldehyde occurred in parallel to give condensed products with a diarylmethane structure. Because these phenolic dimers, G1 and G2, were recovered from the guaiacyl unit linked with the neighboring guaiacyl units via two Beta-aryl-ether bonds, they are promising lignin-derived chemicals that are obtainable in a high yield.

Hardwood lignin in eucalyptus was first converted to hardwood lignocresol through a phase separation process utilizing wood meal, sulfuric acid, and p-cresol at ambient temperature. A syringyl methyl benzofuran, S2 was selectively obtained via a syringyl-type phenolic dimer with a coumaran ring, S1 by NaOH treatments of hardwood lignocresol at 170 °C. Our process controls the reactivity of Cα linkages, Cβ-aryl-ethers, and Cγ-OH in sequence, successfully resulting in a high yield of specific aromatic chemicals from hardwood lignin based on the successiveness of Cβ-aryl-ethers between syringyl units.

The cost of cellulase is a major factor limiting the enzymatic hydrolysis of cellulosic biomass. Thus, immobilization of cellulase would be an important advancement. Lignophenol is a lignin-based functional phenolic polymer synthesized from a lignocellulosic material and a phenol derivative at ambient temperature. Cellulase derived from Trichoderma reesei is easily immobilized by softwood and hardwood lignocresol simply by mixing to produce a water-insoluble lignophenol-cellulase complex. Enzymatic hydrolysis performances of cellulases immobilized on lignocresols are approximately 80–90% and 30–50% relative to that of free cellulase in the hydrolysis of carboxymethylcellulose (CMC) and filter paper, respectively. Cellulase was active enough even after adsorption on lignocresols. Limited physical contact between solid substrates and immobilized cellulase due to the presence of lignocresol seems to lead to lower enzymatic activity for solid substrates. Hardwood lignocresol-immobilized cellulase exh...

Steam-exploded eucalyptus wood chips were treated with p-cresol and 72% sulfuric acid at ambient temperature. Steam-exploded lignin was isolated as acetone-soluble and diethyl ether-insoluble compounds from the cresol layer. The lignin extraction yield was only 47%, and the amount of cresol grafted to lignin was much less than that in the case of eucalyptus lignin without steam explosion. Clearly, the steam explosion process depolymerized native lignin, and simultaneously, promoted polymerization via labile benzyl positions. The steam-exploded eucalyptus lignin adsorbed more Trichoderma reesei cellulase; however, its enzymatic activity was less than that of eucalyptus lignin that did not undergo steam explosion. It is evident that pretreatment potentially affects the affinity between lignin and cellulase and the resultant saccharification efficiency.

A model lignin-binding cellulase was prepared from Trichoderma reesei cellulase and lignocresol, which was synthesized from softwood or hardwood lignin. Filter paper was incubated with the lignocresol-cellulase complex, and it was observed that only a limited amount of cellulase migrated to the filter paper. The cellulase adsorption isotherms for the lignocresols and filter paper were fitted to a Langmuir absorption model, and the determined Langmuir constants were as follows: softwood lignocresol>hardwood lignocresol>>filter paper. The calculations demonstrated that lignin-binding cellulase can potentially be recovered by the addition of a sufficient quantity of cellulosic substrate. As a result, the lignocresol-binding cellulase is highly stable and lignocresol can potentially be used for immobilizing cellulase in the active state.

Lignin is the most abundant and complicated natural polymer, forming long-term carbon flow in the ecosystem. Lignin is composed of phenyl propane units which are the combination of glycerol- and polyhydric phenol units. A key for sequential functionality control is how to control C1- (7%) and C2- (50%) aryl ethers selectively. The cleavage of C1 aryl ethers results in the transformation of polymer structures from network to linear-type, and that at C2 leads to depolymerization to dimer–oligomer level. The originally designed sequential transformation system includes two steps: 1st step; the selective control of C1 structures to give 1,1-bis(aryl)propane type units, leading to the standardization of C1 functionality, 2nd step; the selective control of C2 structures using intramolecular switching devices [1,1-bis(aryl)propane-2-O-aryl ether units], leading to the change of molecular weight and phenolic activity. The polymers, lignophenols, derived from native lignin through C1 control are multi-functional lignin-based materials, linear types of lignin subunits with phenol derivatives at C1. Sequential applications have been designed originally.

Lignophenol (LP)-graft-poly(2-ethyl-2-oxazoline) (POZO) was prepared to reuse lignin, an industrial waste material, and to produce novel LP-based polymer blends with poly(vinyl chloride) (PVC), poly(bisphenol A carbonate) (PC), polyvinylpyrrolidone (PVP), and polystyrene (PSt) as commodity polymers. The resulting graft polymer was soluble in various types of organic solvents such as chloroform, THF, acetone, and methanol, unlike LP. The miscibility of LP-graft-POZO with commodity polymers was measured by differential scanning calorimetry (DSC) to determine the glass transition temperatures (Tg). In the cases of the blends of LP-graft-POZO with PVC, PC, and PVP, the Tg values decreased during the second scan. Moreover, in the cases of the blends with PVC and PVP, the Tg values were not detected during the third scan. Therefore, it was inferred that LP-graft-POZO was miscible with PVC, PC, and PVP while forming single phases; in particular, the blends of LP-graft-POZO with PVC and PVP exhibited a secondary miscibility because the Tg values were not detected. Furthermore, the blend of LP-graft-POZO with PC exhibited better thermostability than LP and LP-graft-POZO. These results indicated that LP blended with POZO could be used as a polymer additive and as an adhesive to combine different polymers, organic–inorganic polymers, etc. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Lignophenol is a novel lignin-based functional polymer. Hydrothermal decomposition of ligno- p -cresol derived from softwood (Douglas fir) was studied from 300 to 400 °C as a candidate technology for modification of the molecular structure and the recovery of monophenols. Ligno- p -cresol was promptly depolymerized probably by hydrolysis of aryl ether linkages and the half was converted to ether-soluble compounds at 300 °C for 10 min. With increasing temperature and reaction time, the yields of char and gas were increased, indicating the acceleration of carbonization and decomposition of monophenols. The monophenols obtained were mainly p -cresol and guaiacol. Their yields only exceed 10% at 365 °C and 60 min probably due to the inefficient pyrolysis of 1,1-bis aryl structures.

Enzymatic hydrolysis of cellulosic biomass by cellulase has been receiving attention. Since the cost of cellulase has a big impact on the price of the products, it is important to develop cheaper alternatives. Here we report on the production of a novel immobilized cellulase. A functional lignin-based phenolic polymer “lignophenol” (p-cresol type : ligno-p-cresol) was synthesized from Hinoki wood meal and p-cresol through the phase separation system developed for selective separation of lignocellulosic components. Commercial cellulase derived from Trichoderma reeseiwas easily immobilized on lignophenol simply by mixing to give water-insoluble cellulase-lignophenol complex. Immobilization reached more than 100 mg/g-lignophenol with an enzymatic activity of about 60% compared to free cellulase. With lower immobilization loads, cellulase exhibited lower activity. Cellulase did not significantly detach from lignophenol by mixing with acetate buffer, indicating that the cellulase immobilized by a simple physical adsorption is stable.

Lignophenol is a lignin-based polymer which highly conserves the native lignin structure. Through simple adsorption experiments between Trichoderma reesei cellulase and softwood lignophenol synthesized from Hinoki cypress and p-cresol, several ideas were obtained on non-productive cellulase binding to lignin expected during enzymatic saccharification of cellulosic substrates. Cellulase is promptly bound to lignin within 10 min. The adsorption reaches a saturated value, indicating that cellulase adsorption on lignin is not multi-layered. Maximum adsorption is observed at around the isoelectric point of cellulase and, at the same time, phenolic hydroxyl groups in lignin seem to enhance cellulase binding. Cellulase bound to lignin maintains its enzymatic activity and probably functions as an immobilized cellulase in saccharification liquor.

Hydroxyl-group-alkoxylated lignophenols (LPs) with various types of alkyl halides were prepared by Williamson ether synthesis to reutilize lignin, an industrial waste material, and make it processable. As compared with raw LP, alkoxylated LPs exhibited good organosolubility and thermal stability (temperatures at 5% loss in weight were estimated to be more than 330 °C by thermogravimetric analyses). Alkoxylated LPs could also form transparent thin films; in particular, films of hexyloxyl LPs exhibited high refractive indices (≈1.55) similar to that of bisphenol A-based poly(carbonate) (PC). Furthermore, these films had lower birefringence (

Lignin is one of the components in the plant cell wall, after cellulose, making up 20-30% of the global plant biomass. Lignophenols (LPs) are derivatives of lignin with high phenolic function and antioxidant properties. However, their medicinal property is not well characterised. Apolipoprotein-B (apo-B) is an essential component in very low-density lipoprotein, and high levels of serum apolipoprotein-B (apo-B) are a major factor for coronary heart disease. In this study, we examined the effect of lignophenols on apo-B secretion in HepG2 cells. HepG2 cells were treated with varying concentrations of LPs and 0.8 mm sodium oleate. LPs decreased oleate-induced apo-B secretion in a dose-dependent manner. LPs also decreased oleate-induced microsomal triglyceride transfer protein (MTTP) mRNA expression and cellular total cholesterol, suggesting that lipid bioavailability and lipidation of lipoprotein are likely involved in the decreased secretion of apo-B. Furthermore, LPs decreased oleate-induced mature sterol regulatory element binding protein 2 (SREBP-2), a transcription factor that activates cholesterol biosynthesis. This is the first study to show that LPs can decrease oleate-induced apo-B secretion in HepG2 cells. The modulations of MTTP mRNA expression, cellular total cholesterol metabolism and mature SREBP-2 expression may be important factors in the regulation of apo-B secretion by LPs.

Two kinds of quaternary amine type lignophenol derivatives were prepared and tested for the adsorption behavior of Au(III), Pd(II), Pt(IV), Cu(II), Fe(III), and Zn(II) in hydrochloric acid medium. Both the derivatives were found to exhibit excellent selectivity for precious metals with negligible adsorption for other metal ions. The adsorption isotherm study established the Langmuir type adsorption model, and from the respective adsorption isotherms, the maximum loading capacities for Au(III), Pd(II), and Pt(IV) were evaluated. Ionic interaction between the positive moiety of quaternary amine functional groups and the anionic chloride complexes formed by the precious metal ions in acidic chloride media was concluded as the main adsorption mechanism.

A tertiary amine type adsorption gel was prepared by the immobilization of dimethylamine onto crosslinked lignophenol (CLP) matrix. This novel product was studied for its adsorption behavior for Au(III), Pd(II), Pt(IV), Cu(II), Zn(II), Ni(II), and Fe(III) in 0.5–6 M hydrochloric acid medium. From our previous study, crosslinked lignophenol (CLP) is known to hold solo selectivity for Au(III). After modification to dimethylamine type adsorbent (DMA-CLP), an extended selectivity of Au(III), Pd(II), and Pt(IV) was observed. The maximum loading capacity for these three metal ions was evaluated by isotherm study. For Au(III) an impressive value of 7.2 mol/kg of DMA-CLP was observed. The feasibility of recovery of precious metals from a mixture containing several other metal ions was studied in batch mode by using both model solution and actual industrial solution obtained after aqua regia leaching of metal components in obsolate e-devices. In addition, a number of adsorption–elution cycles were produced so as to know the feasibility of multiple uses.

本研究では，ファイバーボード工業のゼロエミッション化を目指し，実際に市場に出回っているファイバーボードと，工程廃棄物として生じる成型前ファイバーを相分離系変換処理し，分子素材原料の供給拠点としてなり得るのか，その価値を検討した。その結果，工程廃棄物である蒸煮処理を受けた後Waxを添加されたファイバーは,粉砕および脱脂処理を行わなくても，分子素材誘導原料として十分に利用できるということが明らかとなった。また，接着剤添加後のサンプルから誘導されたリグノフェノールには，熱硬化処理にかかわらず，ユリア-メラミン樹脂由来の成分がごくわずかに含まれていたが，主な性状にはほとんど相違は見られなかった。炭水化物については，MDFのいずれのサンプル糖組成もコントロール試料と類似しており，MDFが分子素材原料の供給拠点として，今後大きな可能性を持っているといえる。

In order to achieve sustainable conversion of lignocellulosics through the phase-separation process, p-hydroxybenzoic acid (p-HBA) attached to core lignin through ester linkage was used as a reagent for lignin conversion. During the phase-separation treatment with p-HBA, the viscosity of reaction mixture was higher, compared with the phase-separation treatment with p-cresol. By centrifugation of the reaction mixture, the thick interfacial solid materials were formed. The yields of lignophenol, its low molecular weight fraction (separated to the organic layer) and the interfacial solid fraction were about 30%, 30% and 40%, respectively. In case of phase-separation treatment with p-cresol, the yields of lignophenol and its low molecular weight fraction (separated to the organic layer) were about 73% and 27%, respectively. The peak ratio of phenol to guaiacol plus syringol in the pyrogram of lignophenol (p-HBA type) was higher than those of lignophenol (p-cresol type) and Klason lignin. The peak of non-conjugated carbonyl group in the FT-IR spectrum of lignophenol (p-HBA type) was higher than that of the material synthesized without p-HBA. These results indicated that p-HBA was grafted to EFB lignin. The lignophenol (p-HBA type) had higher thermal stability, compared with lignophenols (p-Cresol type). The interfacial solid material between the organic and aqueous layers had higher thermal stability than sulfuric acid lignin. These results suggest the formation of lignin network through p-HBA.

This study investigated the effects of lignin-derived lignophenols (LPs) on the oxidative stress and infiltration of macrophages in the kidney of streptozotocin (STZ)-induced diabetic rats. The diabetic rats were divided into four groups with 0%, 0.11%, 0.33% and 1.0% LP diets. The vehicle-injected controls were given a commercial diet. At 5 weeks, superoxide (O(2)(-)) production, macrophage kinetics, the degree of fibrosis in glomeruli and mRNA expression for monocyte chemoattractant protein-1 (MCP-1) were examined. The NADPH-stimulated O(2)(-) levels in the kidney of the diabetic rats treated with 1.0% LP were significantly lower than those in untreated diabetic rats. The number of macrophages, levels of MCP-1 mRNA expression and degree of glomerular fibrosis increased in untreated LP and these levels were significantly lower in 1.0%LP-treated rats. The results suggested that LPs suppress the excess oxidative stress, the infiltration and activation of macrophages and the glomerular expansion in STZ-induced diabetic kidneys.

For the synthesis of a new biologically functional polymer from a natural resource by an environment-friendly method, the laccase-catalyzed polymerization of a lignin-based macromonomer, lignocatechol, was carried out for the first time in ethanol-phosphate buffer solvent system to give crosslinked polymers in good yields. Lignocatechol was prepared by the phase separation system of lignin and catechol in aqueous sulfuric acid. The copolymerization was also performed with urushiol to afford the corresponding copolymers in high yields. The polymerization mechanism was estimated by the IR and pyrolysis GC-MS measurements, suggesting that the polymerization proceeded mainly at the catechol ring through a quinone radical intermediate. The thermal properties were measured by the DSC, TG, and TMA analyses, indicating that the polymers had high thermal stabilities because of the crosslinked structures. In addition, it was found that the resulting polymers had the affinity of bovine serum albumin (BSA) and glucoamylase.

The adsorption behavior of crosslinked lignophenol gel for various metal ions from chloride media was investigated. The gel was found to exhibit selectivity only for Au(III) over a wide range of hydrochloric acid concentration. Also, ethylenediamine group immobilized lignophenol gel (EN–lignin) was found to be selective also for Pd(II) and Pt(IV) with enhanced efficiency for Au(III).