Toshiyuki Takano

• Professor (Full) at Kyoto University

Prolonging the lifespan of timber structures requires early detection of latent deterioration in wood coatings before visible damage occurs. This study combines attenuated total reflectance‐Fourier transform infrared (ATR‐FTIR) spectroscopy with partial least squares (PLS) regression to predict deterioration induced by accelerated weathering (xenon...

Solid dispersion materials of abietic acid (ABA) were prepared with methylcellulose (MC), hydroxypropyl methylcellulose (HPMC), and sodium carboxymethylcellulose (CMC-Na) using a conventional solvent evaporation method. In these materials, ABA was incorporated in an amorphous form. During dissolution tests, ABA from ABA/MC and ABA/HPMC solid disper...

The dynamic adsorption and desorption behaviors of rosin colloids onto and from CNFs and TOCNFs in aqueous media were investigated using QCM-D measurements. Gum rosin colloids (GR-C) were well adsorbed onto CNFs, but not well adsorbed onto TOCNFs. Maleic anhydride modification of GR had little effect on the surface charge but contributed to particl...

This study presents an approach for nondestructive detection of inapparent deterioration in waterborne acrylic coatings (containing cellulose nanofibers (CNFs)) for wood by using mid‐infrared spectroscopy and machine learning. The method evaluates films that mimic coatings before and after 500 h of accelerated weathering, equivalent to roughly 1 ye...

Fruit pedicels act as bridges between the fruit and the shoot. They have secondary thickened cell walls that presumably function in mechanical support, water and nutrient transport. Stone cells are cells with a secondary cell wall thickening. In pears, yet not in apples, the stone cells affect the flesh texture. There have been few reports on stone...

Solid dispersion materials of abietic acid (ABA) in mechanically fibrillated cellulose nanofiber (CNF), TEMPO-oxidized cellulose nanofiber (TOCNF), and partially deacetylated chitin nanofiber (ChNF) without or with aluminum sulfate (Alum) were prepared using a conventional solvent-evaporation method. ABA was retained in basically an amorphous form...

Hydroxypropyl cellulose (HPC) is a stable molecule that presents cholesteric liquid crystal (ChLC) behavior in aqueous systems. However, this ChLC nature has not been fully utilized. In the present study, carboxy groups were introduced to HPC as a means to modify its aqueous ChLC characteristics. 2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO)-oxidati...

The root bark of yellow ginseng (Rennellia elliptica Korth.) is traditionally used as tonic and aphrodisiac by local people in West Kalimantan, Indonesia. This study determined the aphrodisiac activity of the ethanol extract of yellow ginseng root in male DDY mice. A Completely Randomized Design was used in this study, with 5 treatments, i.e., nega...

The demethylation of guaiacyl/syringyl (G/S)-type (G/S = 1/1) and syringyl (S)-type dehydrogenation polymers (DHPs) using iodocyclohexane (ICH) under reflux in DMF was performed to afford demethylated G/S- and S-DHPs in moderate yields. Along with significant structural changes, such as side-chain cleavage and recondensation, as observed using hete...

Developing durable and simple glucose sensing materials is essential to enable the general population an easy method for testing their glucose levels under different environmental conditions. Hence, materials that enable enzyme‐free and intuitive glucose sensing are required. In this study, a system based on an aqueous solution, which enables simpl...

Electro-oxidation of lignin dimer model compounds bearing β−O−4, β−5, and β−β linkages and synthetic lignin (guaiacyl-type dehydrogenation polymer [G-DHP]) in the presence of different mediators previously used in the laccase mediator system (LMS), that is, promazine hydrochloride (PZH), N-hydroxyphthalimide (NHPI), and 2,2′-azino-bis(3-ethyl benzo...

Cellulose, which comprises D-glucose and L-glucose (D,L-cellulose), was synthesized from D-glucose (1D) and L-glucose (1L) via cationic ring-opening polymerization. Specifically, the ring-opening copolymerization of 3-O-benzyl-2,6-di-O-pivaloyl-β-D-glucopyranoside (2D) and 3-O-benzyl-2,6-di-O-pivaloyl-β-D-glucopyranoside (2L), synthesized from comp...

Cellulose, which comprises D-glucose and L-glucose (D,L-cellulose), was synthesized from D-glucose ( 1D ) and L-glucose ( 1L ) via cationic ring-opening polymerization. Specifically, the ring-opening copolymerization of 3- O -benzyl-2,6-di- O -pivaloyl-β-D-glucopyranoside ( 2D ) and 3- O -benzyl-2,6-di- O -pivaloyl-β-D-glucopyranoside ( 2L ), synth...

In the original publication of the article, the letter “ l ” in the section headings was published incorrectly as “l”. It should appear as “ l ” throughout the article.

The enantiomer of natural “d-cellulose” (= “l-cellulose”), which consists of l-glucose, was synthesized from l-glucose via cationic ring-opening polymerization. l-Glucose (1L) was converted to 3-O-benzyl-2,6-di-O-pivaloyl-β-l-glucose 1,2,4-orthopivalate (6L) by five reaction steps. l-Glucose and its derivatives showed almost the same reactivity as...

The existence and formation of covalent lignin‐carbohydrate (LC) linkages in plant cell walls has long been a matter of debate in terms of their roles in cell wall development and biomass utilization. Of the various putative LC linkages proposed to date, evidence of the native existence and formation mechanism of phenyl‐glycoside (PG)‐type LC linka...

This paper reports a new concept for the biorefinery of lignocellulosic biomass where the derivatisation and fractionation of lignocellulose are accomplished at the same time. Methylation of sawdust of Larix kaempferi (Lamb.) Carrière in dimethyl sulfoxide/tetrabutylammonium fluoride followed by fractionation provided three different polymeric deri...

A biomimetic approach to the surface modification of nanocellulose is proposed. This strategy was inspired by plant cell-wall lignification, in which lignin, a hydrophobic biopolymer, tightly assembles cellulose microfibrils and matrix polysaccharides to confer the cell walls with essential mechanical properties. Enzymatic dehydrogenative polymeriz...

The aromatic composition of lignins is considered an important trait that affects the physico-chemical properties of lignocellulosic biomass. However, our knowledge of the relationship between lignin structure and biomass utilization properties remains limited, especially in monocotyledonous grass species, despite their potential as biomass feedsto...

l-Coniferin (1L), which is an enantiomer of natural coniferin (d-coniferin (1D)), was prepared from l-glucose according to the conventional method for compound 1D. The reactivity of l-glucose and its derivatives was found to be almost same as that of the corresponding d-glucose and its derivatives during the preparation for compound 1L. Compound 1L...

Affecting factors to the acyl chitosan isothiocyanate synthesis by N-phenylthiocarbamoylation and the following acylation was investigated using octyl 2-amino-2-deoxy-β-D-glucopyranoside as a model compound. It was found from the acetylation of N-phenylthiocarbamoyl glucosamine derivative with acetic anhydride/pyridine that the glucosamine isothioc...

This paper describes the synthesis of methylcelluloses end-functionalized with peptides and an investigation into their functions. We found that aqueous solutions of methylcellulose end-functionalized not only with carbohydrates but also with peptide segments, such as di(arginine) and di(glutamic acid), behave as thermoresponsive supramolecular hyd...

Among numerous analytical techniques developed for lignins, solution-state multidimensional NMR provides unparalleled details of the polymers’ structural features to be elucidated. With an ability to diagnostically identify and approximate the diverse array of the structural elements in lignin polymers, the NMR techniques are becoming essential in...

Various photosensitizer‐bound cellulose derivatives, in which photosensitizer moieties and substituent groups with long alkyl chains were introduced onto the O‐6 position of cellulose for photon‐to‐electron conversion and O‐2 and O‐3 positions for Langmuir–Blodgett (LB) film formability, respectively, were prepared. The LB monolayer films of porphy...

3,6-Di-O-hexanoyl-N-[4-(N,N-diphenylamino)-1-phenyl] thiocarbamoyl chitosan was prepared from 3,6-di-O-hexanoyl chitosan isothiocyanate in a 78% yield, and spin-coated films of the chitosan derivative and tris(2-phenylpyridine)iridium (Ir(ppy)3) were fabricated. Ultraviolet-visible absorption spectra and photoluminescence spectra of the films indic...

Rennelia elliptica Korth.is locally known as yellow ginseng and has been used as aphrodisiac and folklore medicine. The purpose of the present study was to investigate the LD50 and safety of ethanolic root bark extract of yellow ginseng by acute oral toxicity in DDY mice. The acute oral toxicity study was conducted in accordance with the OECD 425 g...

Introduction The rhizome of Angiopteris evecta is of academic interest in Kalimantan, Indonesia, from an ethnobotanical perspective. Angiopteroside is a substance of pharmaceutical importance that is found in the rhizome of A. evecta. Objective The aims of this research are to improve the extraction method for angiopteroside from the rhizome, comp...

Parasitic plants in the family Orobanchaceae are destructive weeds of agriculture worldwide. The haustorium, an essential parasitic organ used by these plants to penetrate host tissues, is induced by host‐derived phenolic compounds called haustorium‐inducing factors ( HIF s). The origin of HIF s remains unknown, although the structures of lignin mo...

This paper describes the design and synthesis of new trehalose-type diblock methylcellulose analogues with nonionic, cationic, and anionic cellobiosyl segments, namely 1-(tri-O-methyl-cellulosyl)-4-[β-D-glucopyranosyl-(1 → 4)-β-D-glucopyranosyloxymethyl]-1H-1,2,3-triazole (1), 1-(tri-O-methyl-cellulosyl)-4-[(6-amino-6-deoxy-β-D-glucopyranosyl)-(1 →...

The influences of two structural modifications on the photocurrent generation performance of the Langmuir–Blodgett (LB) film of the 6-O-phthalocyaninyl cellulose derivative were investigated. These structural modifications were the substituent groups at the O-2 and O-3 positions, and the central metal of the phthalocyanine moiety. Specifically, 6-O...

Main conclusion: Regulation of a gene encoding coniferaldehyde 5-hydroxylase leads to substantial alterations in lignin structure in rice cell walls, identifying a promising genetic engineering target for improving grass biomass utilization. The aromatic composition of lignin greatly affects utilization characteristics of lignocellulosic biomass a...

Demethylation of guaiacyl-type synthetic lignin (GDHP) with three different reagents, 1-dodecanethiol (DSH), hydroiodic acid (HI), and iodocyclohexane (ICH), was investigated as a basic study for lignin functionalization. Demethylation did not proceed efficiently in the reaction with DSH, although cleavage of the lignin side chains and nucleophilic...

Various Langmuir–Blodgett (LB) films of tetraphenylporphyrin (TPP)-bound acyl celluloses with different degrees of substitution of the TPP groups (DSTPP) and different acyl groups were prepared. TPP-bound acyl celluloses with DSTPP values less than 0.38 and myristoyl groups as the O-2 and O-3 substituents were suitable for obtaining LB mono-layer f...

This paper describes a versatile pathway to heterobifunctional/telechelic cellulose ethers, such as tri-O-methyl cellulosyl azide and propargyl tri-O-methyl celluloside, having one free C-4 hydroxyl group attached to the glucosyl residue at the non-reducing end for the use in Huisgen 1,3-dipolar cycloaddition and copper(I)-catalyzed azide-alkyne cy...

6-O-[Acetylacetonato-bis(2,2′-bipyridine)ruthenium(II)]-2,3-di-O-myristyl cellulose (3) was prepared from 2,3-di-O-myristyl cellulose (1) by two reaction steps in 37.7 % total yield. The LB monolayer film of compound 3 was successfully deposited onto an indium tin oxide electrode by a vertical dipping method and showed photocurrent generation perfo...

A regio-selectively squaraine (SQ)-bounded cellulose derivative (4) with a degree of substitution of SQ (DSSQ) of 0.55 was prepared from 6-O-(4-methoxytrityl) cellulose (1) by three reaction steps in 77% total yield. Lauryl SQ carboxylate (8) was also prepared as a reference sample. The photostability of SQ moieties of compound 4 in CHCl3 was not i...

Oxidation reactions of a non-phenolic β-O-4-type lignin model compound [4-ethoxy-3-methoxyphenylglycerol-β-guaiacyl ether (1)] were conducted in an electrolytic mediator system (EMS) using 2,2,6,6-tetramethyl-1-piperidinyloxyl radical (TEMPO) or 4-acetoamido-TEMPO (AcNH-TEMPO) as mediators. The results revealed that the electrolytes strongly influe...

We recently observed that the decanoylation of N-phenylthiocarbamoyl chitosan (2) with a mixture of decanoic anhydride and pyridine at 60 °C for 24 h afforded N,N-(decanoyl)phenythiocarbamoyl-/2-isothiocynato chitosan decanoate (3b) rather than the expected product N,N-(decanoyl)phenylthiocarbamoyl chitosan decanoate (3a). This result suggested tha...

The selective lignin degradation in a LCC was proceeded with the γ-TTSA method, which is a selective cleavage method for β-O-4 linkages in lignins, in order to obtain more precise information concerning LCC bonding sites. To this purpose, crude MWL from Eucalyptus globulus, containing lignin and xylan, was treated by the γ-TTSA method. This approac...

Bacteria-derived enzymes that can modify specific lignin substructures are potential targets to engineer plants for better biomass processability. The Gram-negative bacterium Sphingobium sp. SYK-6 possesses a Cα-dehydrogenase (LigD) enzyme that has been shown to oxidize the α-hydroxy functionalities in β–O–4-linked dimers into α-keto analogues that...

Chitosan (1) was reacted with phenylisothiocyanate in 5% AcOH/H2O to give N-phenylthiocarbamoyl chitosan (2) with a degree of substitution (DS) of N-phenylthiocarbamoyl groups of 0.86 in 87.1% yield. The following acylation of compound 2 with hexanoyl chloride in the presence of pyridine afforded 3,6-di-O-2,3-hexanoyl chitosan isothiocyanate (4a) w...

The reaction of 6-amino-6-deoxycelluloe (1) with hematin in the presence of N,N′-carbonyldiimidazole and 1,8-diazabicyclo[5.4.0]undec-7-ene in N,N-dimethylformamide at 50°C for four days afforded hematin-appended 6-aminocellulose (2). Compound 2 was more stable than hematin, and retained the oxidation activity of hematin, even after being treated a...

This article describes the first observation of crystallization-induced microphase separation in thin film and bulk cellulose triacetate-block-poly(γ-benzyl-l-glutamate) (PBLG) [cellulose triacetate (CTA)-b-PBLG] via copper-catalyzed azide–alkyne cycloaddition (CuAAC) between azido-functionalized CTA at the reducing end and alkyne-functionalized PB...

Twelve monolignol (coniferyl alcohol, sinapyl alcohol and p-coumaryl alcohol) beta-glycosides (beta-glucosides, beta-galactosides, beta-xylosides and beta-mannosides) were synthesised to obtain fundamental NMR data for the analysis of phenyl glycoside type lignin-carbohydrate complexes (LCCs). That is, the 1,2-trans glycosides (the beta-glucosides,...

Glycoside formation in organic synthesis is believed to occur along a reaction path involving an activated glycosyl donor with a covalent bond between the glycosyl moiety and the leaving group, followed by formation of contact ion pairs with the glycosyl moiety loosely bound to the leaving group, and eventually solvent-separated ion pairs with the...

The 6-O-phthalocyanine cellulose deriv., 2,3-di-O-myristyl-6-O-[p-(9(10),16(17),23(24)-tri-tert-butyl-2-zinc(II)phthalocyaninyl-benzoyl)cellulose (8e) was synthesized in a high yield with the degree of substitution of 0.33 for the phthalocyaninyl group (DSphthalocyanine) via the esterification of 2,3-di-O-myristyl cellulose (1) with the mono-substi...

Milled wood lignin (MWL) of Eucalyptus globulus has been treated by a selective degradation method for beta-O-4 linkages, which lets the lignin carbohydrate complexes (LCC) intact. The method consists of four reaction steps: (1) gamma-tosylation, (2) thioetherification, (3) sulfonylation and (4) mild alkali treatment (gamma-TTSA method). Each step...

The tandem Staudinger/aza-Wittig reaction of the 6-azido-6-deoxycellulose derivative (2) with triphenylphosphine and carbon disulfide afforded the corresponding 6-isothiocyanato-6-deoxycellulose derivative (3) in 47.3% yield. Compound 3 was further reacted with 4'-aminobenzo-15-crown ether to afford the crown ether-containing 6-N-thioureido-6-deoxy...

A review. Synthesis and characterization of cellulose, xylan and glucomannan derivs. and their properties are studied for applications. Various end-functionalized cellulose derivs. were prepd. by introduction of functional groups at the reducing-end. Prepn. and characterization of cellulose diblock copolymers, graft copolymers with cellulose side-c...

The electrooxidns. of nonphenolic lignin model compds. in an electrolytic mediator system (EMS) were studied with several laccase mediators, including N-hydroxyphthalimide (NHPI), 1-hydroxybenzotriazole (HBT), violuric acid (VLA), 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO), and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS), under the...

The residual wood meal left after milled wood lignin (MWL) isolation [milled wood residue (MWR)] of 5-yr-old Eucalyptus globulus was fractionated to afford a xylan-lignin fraction (X-L) in 2.9% yield (based on MWR) by the method reported previously. X-L was further fractionated with the lignin solvent 1,4-dioxane/water (9:1, vol./vol.) to give a so...

Cross‐linking of various types of pre‐oxidized lignins with oligo(oxyalkylene)‐,‐diglycidyl ethers under alkaline conditions were demonstrated to afford mechanically stable lignin xerogels with free swelling capacities of up to 75 g H2O per g of cross‐linked lignin depending on the type of lignin, pre‐activation (pH, type of alkali hydroxide), ex...

A selective cleavage method for beta-O-4 linkages (the gamma-TTSA method) was introduced in previous works, which consists of four reaction steps: (1) gamma-tosylation, (2) thioetherification, (3) sulfonylation, and (4) mild alkali degradation. This method was applied to the degradation of a lignin polymer model (dehydrogenation polymer, DHP) consi...

2,3-Di-O-myristyl-6-O-(zinc(II) phthalocyaninyl) cellulose (5) was synthesized from cellulose (1) by five reaction steps via 6-O-(3′,4′-dicyanophenyl)-2,3-di-O-myristyl cellulose (4). The key reaction was phthalocyanine-ring formation on a cellulose backbone, that is, the reaction of compound 4 with o-phthalodinitrile in the presence of hexamethyld...

A novel synthetic method to link acetylated cellulose derivatives with methylated cellulose derivatives via Huisgen 1,3-dipolar cycloaddition was developed to produce 1,2,3-triazole-linked diblock copolymers consisting of hydrophilic cellobiose or low-molecular-weight cellulose and a hydrophobic 2,3,6-tri-O-methyl-cellulose. Huisgen 1,3-dipolar cyc...

For the first time, 2-O-methyl- (2MC) and 3,6-di-O-methyl-cellulose (36MC) were synthesized via 3-O-allyl- and 3-O-methyl-cellulose, respectively. Position 6 of 3-O-allyl- and 3-O-methyl-cellulose was protected with the 4-methoxytrityl groups. The reaction time and temperature were optimized to achieve a high regioselectivity at C-6 and to prevent...

The residual wood meal left after milled wood lignin (MWL) isolation (MWR) was extd. with the cellulose solvent lithium chloride/N,N-dimethylacetamide (LiCl/DMAc) to obtain a sol. fraction (C-L) and an insol. fraction (C-L-residue). The C-L-residue was further extd. with the hemicellulose solvent 3 M NaOH to give a sol. fraction named hemicellulose...

The direct anodic oxidation of non-phenolic lignin model compounds was investigated to understand their basic behaviors. The results of cyclic voltammetry (CV) studies of monomeric model, such as 1-(4-ethoxy-3-methoxyphenyl)ethanol, are interpreted as the oxidation for C-alpha-carbonylation did not proceed in the reaction without a catalyst, but a...

The N-hydroxyphthalimide (NHPI)-mediated indirect electro-oxidation of non-phenolic lignin model compounds has been investigated for selective C-alpha-carbonylation of lignin. A cyclic voltammogram of NHPI in 0.1 M LiClO4/CH3CN with 2,6-lutidine interpreted that NHPI can act as a mediator in the indicated process in the range 0.5-0.8 V vs. Ag/Ag+....

The alpha-TSA method has been developed for the cleavage of beta-O-4 linkages in lignin. It consists of three steps: ( 1) thioetherification at alpha-position of beta-O-4 substructures, ( 2) sulfonylation, and ( 3) mild alkali treatment of the alpha-sulfone derivative. The method was tested on a nonphenolic dimeric beta-O-4 lignin model compound, n...

Comb-shaped copolymers with cellobiose acetate or cellulose triacetate (CIA) side-chains. PPMA-g-(CTA2-C15) and PPMA-g-(CTA13-C15), were prepared by grafting N-(15-azidopentadecanoyl)-2,3,6-tri-O-acetyl-4-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-beta-D-glucopyranosylamine (CTA2-C15-N-3) and N-(15-azidopentadecanoyl)-tri-O-acetyl-beta-cellul...

6-Azafulleroid-6-deoxy-2,3-di-O-myristoylcellulose (3) was synthesized from 6-azido-6-deoxycellulose (1) by two reaction steps. The myristoylation of compound 1 with myristoyl chloride/pyridine proceeded smoothly to give 6-azido-6-deoxy-2,3-di-O-myristoylcellulose (2) in 97.0% yield. The reaction of compound 2 with fullerene (C(60)) was carried out...

Cellulose chains bearing N-lipoyl group at the reducing-end as a sulfide linker, self-assembled on the surface of gold nanoparticles (CELL2Au, CELL13Au, and CELL41Au with the number average degrees of polymerization (DPn) of 2, 13, and 41, respectively) were prepared. CELL2Au, CELL13Au, and CELL41Au were obtained via deprotection of the cellulose t...

Self-assembled cellulose-pyrene nanoparticles were prepared from amphiphilic cellulose derivatives carrying a single pyrene group at the reducing-end, N-(1-pyrenebutyloyl)-β-cellulosylamine (CELL13Py and CELL30Py, the number average degrees of polymerization (DPn) of 13 and 30, respectively) and N-(15-(1-pyrenebutyloylamino)-pentadecanoyl)-β-cellul...

New carbohydrate-based surfactants consisting of hydrophilic cellobiosyl and hydrophobic glucosyl residues, methyl β-d-glucopyranosyl-(1→4)-α-d-glucopyranosyl-(1→4)-2,3,6-tri-O-methyl-α-d-glucopyranoside 1 (GβGαMα, G: glucopyranosyl residue, α and β: α-(1→4)- and β-(1→4) glycosidic bonds, M: methyl group), 2 (G(β)G(β)M(α)), 3 (G(β)G(α)M(β)), 4 (G(β...

In order to elucidate the characteristic features of commercial methylcellulose precisely, O-methylcellulose model copolymers consisting of 2,3,6-tri-O-methylanhydroglucose unit (236MeAGU) and 2-O-methylanhydroglucose unit (2MeAGU) with various composition ratios were synthesized via cationic ring-opening copolymerization of the corresponding gluco...

Cellulose triacetate (CTA) derivatives having a disulfide group at the reducing-end (CTA2S, CTA13S, CTA41S), with number average degrees of polymerization (DPns) of 2, 13 and 41, respectively, were prepared. The CTA-self-assembled gold nanoparticles (CTA2Au, CTA13Au, and CTA41Au) were obtained through the reduction of gold salt (HAuCl4) with CTASs....

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Persimmon (Diospyros kaki Thunb.) accumulates soluble condensed tannin (CT) in fruit which is responsible for its astringency trait. In this study, we analyzed the CT composition in persimmon fruit with phloroglucinol, and identified and characterized novel epigallocatechin-3-O-gallate-phloroglucinol (EGCG-P) adducts as one of the main CT component...

Regioselectively ethylated celluloses, 2‐ O ‐ ( 1 ), 3‐ O ‐ ( 2 ), and 6‐ O ‐ethyl‐ ( 3 ) celluloses were synthesized via ring‐opening polymerization of glucopyranose orthopivalate derivatives. The number‐average degrees of polymerization ( DP n s) of compounds 1 and 2 were calculated to be 10.6 and 49.4, respectively. Three kinds of compound 3 wit...

It is known that the conventional dehydrogenative polymerization of sinapyl alcohol (S-alc) gave syringyl synthetic lignins (S-DHPs), but in extremely low yields. In this article, to examine the contribution of syringyl quinone methide intermediates (S-QM) on S-DHP production, horseradish peroxidase (HRP)-catalyzed dehydrogenative polymerization of...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Horseradish peroxidase (HRP)-catalyzed dehydrogenative polymerization of guaiacyl (G) and syringyl (S)-type monolignol γ-O-glucosides, isoconiferin (iso-G) and isosyringin (iso-S), which contain a hydrophilic glucosyl unit on γ-position of coniferyl alcohol and sinapyl alcohol, respectively, was monitored by gel permeation chromatography coupled wi...

The solvent pH effect in the horseradish peroxidase (HRP)-catalyzed polymerization of sinapyl alcohol (S-alc) and analogously, sinapyl alcohol γ-O-glucoside (isosyringin, iso-S) was investigated particularly focusing on the behavior of syringyl-type quinone methide intermediates (S-type QMs) under acidic conditions. At first, the HRP-catalyzed poly...

6-O-Alkyl-celluloses with well-defined ratio of ethyl and methyl groups at position 6 were prepared by ring-opening copolymerization of 6-O-ethyl and 6-O-methyl glucose 1,2,4-orthopivalate derivatives. An aqueous solution of 6-O-ethyl-cellulose having no methyl group was found to be thermo-responsive to be turbid at ~70°C. An aqueous solution of 6-...

2,6-Di-O-ethyl (2E6E) (1), 2-O-ethyl-6-O-methyl (2E6M) (2), and 6-O-ethyl-2-O-methyl (6E2M) (3) celluloses were synthesized via ring-opening polymerization of glucose orthopivalate derivatives. 2,6-Di-O-methyl cellulose (2M6M) was insoluble in any common solvents, though it was not expected. On the other hand, cellulose derivative 1 (2E6E) was solu...

(13)C-Perlabeled cellulose was obtained in a seven-step approach from (13)C(6)-labeled d-glucose with a cationic ring-opening polymerization as the key step. Isopropylidene protection, benzylation of the remaining free 3-O-position and subsequent deprotection afforded 3-O-benzyl-(13)C(6)-glucose (2). Regioselective bis-pivaloylation followed by sub...

A cellulose macromonomer, N-(15-methacryloyloxypentadecanoyl)-tri-O-acetyl-beta-cellulosylamine (CTA-C15-MA (2); M(2)) with number averaged degree of polymerization (DP(n)) = 13), was copolymerized with methyl methacrylate (MMA; M(1)) to give cellulosic copolymer with CTA side chains, PMMA-g-(CTA-C15) (3-A). An absolute molecular weight determined...

Model experiments for synthesis of a comb-shaped copolymer with cellulose side-chains were performed with cellobiose derivatives. A novel cellobiose monomer, N-(15-methacryloyloxypentadecanoyl)-2,3,6-tri-O-acetyl-4-O-(2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl)-β-d-glucopyranosylamine (2) was prepared from heptaacetylcellobiosyl- amine. Homopolymeri...

The syntheses of two perdeuterated ionic liqs. (ILs), 1-ethyl-3-methylimidazolium acetate and 1-butyl-3-methylimidazolium acetate, were described. The targets were obtained from perdeuterated imidazole in three-step sequences starting with ethylation and butylation, resp. The resulting perdeuterated 1-alkyl imidazoles were purified, and subsequentl...

Horseradish peroxidase (HRP)-initiated dehydrogenative polymerizations of guaiacyl (G) and syringyl (S)-type monolignol γ-O-glucosides, isoconiferin (iso-G) and isosyringin (iso-S), which contain a hydrophilic glucosyl unit on γ-position of coniferyl alcohol (G-alc) and sinapyl alcohol (S-alc), respectively, were monitored by UV spectroscopy to stu...

Horseradish peroxidase (HRP)-catalyzed dehydrogenative copolymerization of guaiacyl (G)-type monolignol glycoside (isoconiferin, coniferyl alcohol γ-O-β-d-glucopyranoside, iso-G) and syringyl (S)-type monolignol glycoside (isosyringin, sinapyl alcohol γ-O-β-d-glucopyranoside, iso-S) were performed in continuous dehydrogenation mode (end-wise polyme...

Formaldehyde adsorption and release tests of karamatsu (Larix leptolepis) bark and bark ingredients were performed. Karamatsu bark had good formaldehyde adsorption ability that was better than microcrystalline cellulose. An acetone-soluble fraction from karamatsu bark, which might contain bark tannin, had excellent formaldehyde adsorption ability,...

The reaction of (+)-catechin with formaldehyde vapor was investigated as a model reaction of formaldehyde adsorption of (+)-catechin. It was found by H nuclear magnetic resonance spectroscopy, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and gel permeation chromatography of the product that the vapor reaction of (+)...

Horseradish peroxidase–catalyzed dehydrogenative polymerizations of the p-hydroxyphenyl monolignol glucoside (triandrin (1P)) and the syringyl monolignol glucoside (isosyringin (1S)) resulted in the formation of water-soluble lignin-like polymers (DHPs). The polymerization of 1P gave highly polymerized DHPs in high yields as did previously reported...

The syntheses of several perdeuterated substances—some of them isotopically labeled (15N) in addition—are described, which act as direct solvents of cellulose either on their own, such as N-methylmorpholine N-oxide (NMMO), 1-butyl-3-methylimidazolium acetate (BMIM-OAc), or 1-ethyl-3-methylimidazolium acetate (EMIM-OAc), or in combination with auxil...

Azide ion as a quinone methide scavenger in the horseradish peroxidase-catalyzed polymerization of sinapyl alcohol Key words Azide ion · Dehydrogenation polymer (DHP) · Horseradish peroxidase (HRP) · Quinone methide · Sinapyl alcohol

Microwave heating was applied to the reactions involved in the synthesis of 6-amino-6-deoxycellulose, 4. These included, cellulose solubilization, bromination at C-6, displacement of bromine with azide ion, and reduction of the azido group to an amino group. Compared to conventional heating, this approach had the advantages of shortening reaction t...

The ATR-FTIR method (with KRS-5 IRE and an incident angle 6 = 45 °) was applied for determining the surface degree of substitution (DSs) of a cellulose acetate film. Acetylation of a regenerated cellulose film with Ac2O/AcOH at 100°C for 24 h without pretreatment gave no results, whereas that with AcOH pretreatment, at room temperature, afforded a...

Six highly regioregular O-methycelluloses (rr-MCs) with DS of 1.0 or 2.0, that is, 2-0- (2MC), 3-0- (3MC), 6-0- (6MC), 2,3-di-O- (23MC), 2,6-di-O- (26MC) and 3,6-di-O- (36MC) methylcelluloses were prepared. According to the water solubility test applied, all rr-MCs were insoluble at a 2% concentration, suggesting that the regioregularity of the rr-...

Copolymerization of 3,6-di-O-methyl-α-D-glucopyranose 1,2,4-orthopivalate (1), of 3-O-allyl-6-O-methyl-α-D-glucopyranose 1,2,4-orthopivalatc (2), 3,6-di-O-allyl-α-D-glucopyranose 1,2,4-orthopivalate (3) proceeded similarly with homopolymerization of compounds 1, 2 and 3, giving the corresponding stereo-regular β-1,4-glucans 4 and 5. with heterogene...