A mouse monoclonal antibody was generated against a beta-O-4 oligomer-p-aminohippuric acid-(pAHA)-bovine serum albumin (BSA) conjugate. Competitive ELISA showed that the antibody reacted specifically with beta-O-4 oligomer conjugate and did not react with other dimeric model compound conjugates containing the beta-5, beta-beta, or 5-5 linkages. This antibody reacted with both the beta-O-4 linked guaiacyl and syringyl structures. In Chamaecyparis obtusa, labeling was strong in the secondary walls (SW), and weak in the compound middle lamella (CML). In Betula grossa, labeling was strong in the outer SW of wood fibers and uniform in the SW of vessel elements and the inner part of the SW of wood fibers. In contrast, labeling was strong in wood fibers rich in syringyl lignin in Quercus crispula and weak in CML, including cell corners, the SW of vessel elements, and vasicentric tracheids rich in guaiacyl lignin. In Phyllostachys edulis, labeling was uniform in developing fiber SW and stronger in inner part in developed fiber SW. The localization patterns were like those of feruloyl arabinoxylan epitopes. This novel antibody will be an effective tool to immunolocalize the beta-O-4 linked structure of lignin in plant cell walls.

Microbial conversion offers an alternative approach to modifying the structure of bioactive compounds, enabling selective transformations that are often difficult to achieve and more eco-friendly than chemical synthesis. In this study, rubiadin was bioconverted using the endophytic fungus Lasiodiplodia theobromae strain GKBT-02, isolated from Rennellia elliptica (Rubiaceae). Because rubiadin is limited in nature, it was synthesized from phthalic anhydride and 2,6-dihydroxytoluene. The microbial conversion was carried out in glucose-yeast extract-peptone (GYP) liquid medium at room temperature for 4 days, yielding 20.6% of the converted product. The chemical structure of the bioconversion product was elucidated through 1D- and 2D-NMR, mass spectrometry, and comparison with published data, leading to its identification as 6-hydroxyrubiadin. In the in-vitro MTT assay, 6-hydroxyrubiadin exhibited slightly weaker antiproliferative activity than that of rubiadin, with IC₅₀ values of 0.19 and 0.22 μM against MCF-7 and T47D cancer cell lines, respectively. Docking studies further revealed that both rubiadin and 6-hydroxyrubiadin displayed potent EGFR inhibitory activity, with the converted product showing stronger interactions with the epidermal growth factor receptor (EGFR) than the commercial EGFR inhibitor used as a positive control.

This study describes a novel method for synthesizing ethyl cellulose (EC) via the metal-catalyzed reductive deoxygenation of commercial cellulose triacetate (CTA). Herein we explore suitable combinations of group 13 metal catalysts and hydrosilanes that enable the conversion of acetyl groups on CTA to ethyl groups, followed by the characterization and functional analysis of the resulting EC. The combination of InBr3 and triethylsilane successfully reduced CTA with various molecular weights, affording EC derivatives with ethyl, acetyl, and triethylsilyl substituents. The removal of the acetyl and triethylsilyl groups yielded water-soluble ECs with a degree of substitution of ethyl groups between 0.5 and 0.7. NMR analyses revealed that the reductively synthesized ECs unexpectedly had ethyl groups preferentially substituted at the C6 position (≈60%), contrary to EC synthesized by the SN2 reaction, which show preferential ethylation at the C2 position. Moreover, the ECs obtained via reduction exhibited different aggregation behaviors in aqueous solutions from those synthesized via nucleophilic substitution. These results indicate that the reductive deoxygenation of CTA affords EC with a substitution pattern distinct from that of conventionally synthesized ones, leading to unique functions. This study paves the way for a new synthetic paradigm that expands structural and functional diversity of cellulose ethers.

Chirality is a fundamental feature involved in most biological processes. While it can be rather readily observed on the molecular or microscopic level, enantioselective interactions on the macroscopic level are not as well understood. We chemically synthesized l-cellulose, the enantiomer of native cellulose with chains of different length by polymerizing an l-glucose-based precursor. A sufficiently high degree of polymerization was crucial for the successful application of this material as a chiral selector. After derivatization, coating onto silica, and packing into columns, the functionalized material was tested in a chiral high-performance liquid chromatography setup to investigate the enantioselective interplay between the modified cellulose mirror images and chiral molecules. We report the first-ever application of synthetic l-cellulose instead of the common column materials based on the natural d-polysaccharide counterparts. An inversion of the analyte elution order of (R) and (S) enantiomers due to reversed interaction strength with the stationary phase was observed for all tested analytes.

This work describes a model study for synthesis of cellulose-based block copolymers, investigating selective coupling of peracetyl beta-d-cellobiose and perethyl beta-d-cellobiose at their reducing-ends by olefin cross-metathesis (CM). Herein we explore suitable pairs of omega-alkenamides that permit selective, quantitative coupling by CM. Condensation reactions of hepta-O-acetyl-beta-d-cellobiosylamine or hepta-O-ethyl-beta-d-cellobiosylamine with acyl chlorides afforded the corresponding N-(beta-d-cellobiosyl)-omega-alkenamide derivatives with an aromatic olefin or linear olefinic structures. Among the introduced olefinic structures, CM of the undec-10-enamide (Type I olefin) and the acrylamide (Type II olefin) gave the hetero-block tetramers, N-(hepta-O-ethyl-beta-d-cellobiosyl)-N '-(hepta-O-acetyl-beta-d-cellobiosyl)-alkene-alpha,omega-diamides, with >98 % selectivity. Moreover, selectivity was not influenced by the cellobiose substituents when a Type I olefin with a long alkyl tether was used. Although the amide carbonyl group could chelate the ruthenium atom and reduce CM selectivity, the results indicated that such chelation is suppressed by sterically hindered pyranose rings or the long alkyl chain between the amido group and the double bond. Based on this model study, selective end-to-end coupling of tri-O-ethyl cellulose and acetylated cellobiose was accomplished, proving the concept that this model study with cellobiose derivatives is a useful signpost for selective synthesis of polysaccharide-based block copolymers.

For the first time, stone cells in pear and apple pedicel were studied. The lignification of the pedicel outer part was correlated with flesh, and the secondary cell wall biosynthesis genes were activated. 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 cell formation in pear and apple pedicels; therefore, we studied these cells for the first time. The apple pedicel had few stone cells in the cortex. The formation of stone cells in pear continued until seven weeks after flowering (WAF), and the density was significantly higher than in apple. The stone cell formation degree (SFD) of pear was 3.6–7.1 times higher than that of apple. Total lignin and lignin non-condensed structure (G and S units) content in the pear pedicle outer part was 1.5–2.7 times higher than that of the apple at harvest. The SFD of the pedicel outer part had a positive correlation with the G and S units content of the flesh. The total lignin and G and S units content between flesh and the pedicel outer part were positively correlated. Correlation analysis revealed a positive relationship between fruit and pedicel formation of the stone cells. The WGCNA showed that NST3 was linked to NAC028, MYB46, CESA, POD, LAC, and VSR6. These genes were highly expressed in the outer part of the pear pedicel, while they were suppressed in that issue of the apple at 4 WAF.

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., negative control (1% Na-CMC), positive control (sildenafil citrate) (5 mg/kg BW), yellow ginseng ethanol extract (50 mg/kg), yellow ginseng ethanol extract (100 mg/kg BW), yellow ginseng ethanol extract (250 mg/kg BW). The treatment was administered orally once a day by oral gavage. The duration of extract administration was 3, 5, and 10 days. The results showed that the administration of yellow ginseng ethanol extract at a dose of 250 mg/kg BW for 3 days increased libido as an indication of aphrodisiac activity. The administration of yellow ginseng extract for 10 days indicated prolonged ejaculation. However, this result was not statistically significant (p>0.05) compared to negative and positive control treatments.

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 heteronuclear single quantum coherence (HSQC) NMR spectra, the phenolic-OH content of the demethylated DHPs increased, as expected. The tannin-like properties, such as the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging ability, iron(III) binding ability, and bovine serum albumin (BSA) adsorption ability, of the demethylated DHPs increased with increasing reaction time. In particular, the BSA adsorption ability was significantly enhanced by demethylation of the G/S- and S-DHPs, and was better than that of G-DHP reported previously. These results indicate that hardwood lignin containing both G and S units is more suitable than softwood lignin containing only G units for functionalization through demethylation into a tannin-like polymer, which has applications as a natural oxidant, metal adsorbent, and protein adsorbent.

Electro-oxidation of lignin dimer model compounds bearing beta-O-4, beta-5, and beta-beta 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-ethylbenzothiazoline-6-sulfonic acid) (ABTS), was investigated. The characteristics of the electro-oxidations of the lignin dimer model compounds were reflected in the electro-oxidation of G-DHP. The three mediators effectively mediated the electro-oxidation of G-DHP, although they showed different reaction selectivities toward the three major lignin linkages of G-DHP. Specifically, PZH preferentially mediated the oxidation of beta-O-4 and beta-beta linkages over beta-5 linkages, NHPI preferred beta-O-4 linkages over beta-5 and beta-beta linkages, and ABTS preferred beta-O-4 and beta-beta linkages over beta-5 linkages under the present conditions. NHPI and ABTS tended to mediate C alpha-C beta cleavage in contrast to PZH, and the three mediators all mediated the conversion of coniferyl alcohol end-units. Consequently, PZH, NHPI, and ABTS were found to be promising mediators for the electrolytic mediator system of lignin.

In this paper, we developed a microbial route to fabricate wood-inspired biomimetic composites comparable to natural wood. Focusing on the chemical composition of woody biomass, we performed in situ bioprocessing of bacterial cellulose (BC) imbibed in modified cationic lignin (Catlig), which exhibited significant bioactivity in improving the microbial growth dynamics. The structural and morphological characteristics were enhanced by the formation of hydrophobic and electrostatic interactions between BC and Catlig during biosynthesis. Microbially derived BC/Catlig composites exhibited enhanced thermal stability and crystallinity, with oriented cellulose fibers. The tensile properties, toughness, and specific strength of BC/Catlig composites were comparable to those of a heavy wood species (Zelkova serrata) under hydrated conditions and synthetic soft materials.

Transition-metal complexes Mn(acac)2, Mn(bpy)3, Fe(acac)2, and Fe(bpy)3 were investigated as mediators in lignin oxidation with an electrolytic mediator system (EMS). Fe(bpy)3 was screened among them as a mediator in the bulk electrolysis of a lignin dimer model compound (4-ethoxy3-methoxyphenylglycerol-beta-guaiacyl ether: 3G) and guaiacyl-type dehydrogenation polymer (G-DHP) by experiments using the lignin monomer model compound 1-(4-ethoxy-3-methoxyphenyl)ethanol. In Fe(bpy)3-mediated electro-oxidations of compound 3G, both C alpha-C beta cleavage and C alpha-carbonylation proceeded efficiently in 0.1 M LiClO4/70%-CH3CN/H2O, whereas C alpha- carbonylation predominated in 10%-dioxane/0.1 M acetate buffer (pH 4). Fe(bpy)3-mediated electro-oxidation of G-DHP also proceeded efficiently via both C alpha-C beta cleavage and C alpha-carbonylation in 0.1 M LiClO4/70%-CH3CN/ H2O. The oxidation was promoted by the addition of 2,6-lutidine as a base. By contrast, the Fe(bpy)3-mediated electro-oxidations of G-DHP did not proceed efficiently in 10%-dioxane/0.1 M acetate buffer (pH 4) with or without 2,6-lutidine under the present conditions. It was reconfirmed that electrolyte was also one of the important factors in lignin oxidation with EMS. Consequently, Fe(bpy)3 was found to be a promising mediator of lignin EMS for lignin modification and degradation.

Various acylates and phenylcarbamates of (ethyl)cellulose (EC) were synthesized by acylation and carbanilation, respectively, of the residual hydroxyls of an EC (ethyl DS = 2.50). The acyl substituents adopted were propionyl, butyryl, cyclohexanoyl, and adamantoyl groups, and the phenylcarbamoyl substituents included 3-chlorophenylcarbamoyl, 4-chlorophenylcarbamoyl, 3-methylphenylcarbamoyl, and bare phenylcarbamoyl groups. Chiral nematic mesophases of the EC derivatives, formed in chloroform, acetic acid (AA), and dichloroacetic acid (DCA), were examined by various optical techniques for evaluation of the helical pitch (P) in a set of absolute value and twist sense. The lyotropic samples prepared with DCA (20 degrees C) always assumed a right-handed chiral nematic structure, regardless of the degree of acyl (or phenylcarbamoyl) substitution (DSAcyl (or DSPC), <= 0.50). The chiral nematic series with AA (20 degrees C) and chloroform (5 degrees C) showed an inversion of the twist sense from being left-handed to right-handed, when DSAcyl (or DSPC) of each derivative was increased. The critical DS value for the inversion varied depending on the chain length, bulkiness, and polar nature of the employed substituent. For all of the lyotropic series explored, it was generalized that a temperature elevation strengthens a lefthanded twisting power in each chiral nematic mesophase. Reversal of the twist handedness was also observed in a cycle of heating and cooling of some chiral nematics in AA. This was interpreted as being due to compensation in the strength of the two chiral interactions, i.e., steric repulsion and dispersion interaction between mesogenic molecules, contributing in mutually opposite signs to the twisting power (2 pi P-1) of the mesophase.

This work demonstrates a unique approach of utilizing alkali lignin (AL), as smart additive to in situ BC fermentation in which it concurrently acts as promoter to microbial growth as well as reinforcing filler for fabrication of multifunctional composites. Traditionally, BC fermentation is accompanied by inhibitor formation with sudden drop in pH leading to low yield and biomass growth. AL due to its antioxidant nature prevents formation of gluconic acid as byproduct, at ∼0.25 wt.% AL based on inhibitory byproduct kinetics. Interestingly, AL self-assembles to form primary and secondary structures in BC pores, resulting in simultaneous improvement in thermal stability as well as toughness. The BC/AL films show strong UV-blocking capacity with prolonged radical scavenging activity and preventing browning of freshly cut apples making it suitable as food packaging. Therefore, present work opens up new avenues for fabrication of high-performance BC-based composites through selection of smart materials which can simultaneously improve BC bioprocessing.

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 compounds 1D and 1L, respectively, in a 1:1 ratio, afforded 3-O-benzyl-2,6-di-O-β-D,L-glucopyranan (3DL) with a degree of polymerization (DPn) of 28.5 (Mw/Mn = 1.90) in quantitative yield. The deprotection of compound 3DL and subsequent acetylation proceeded smoothly to afford acetylated compound 4DL with a DPn of 18.6 (Mw/Mn = 2.08). The specific rotation of acetylated compound 4DL was + 0.01°, suggesting that acetylated compound 4DL was optically inactive cellulose triacetate. Furthermore, before acetylation, compound 4DL was an optically inactive cellulose comprising an almost racemic mixture of D-glucose and L-glucose. Compound 4DL was an amorphous polymer. This is the first reported synthesis of optically inactive D,L-cellulose.

: Carbohydrate-binding modules (CBMs) are non-catalytic protein domains that bind to carbohydrates, and have been well studied in microorganisms. Endogenous CBMs in aquatic invertebrates, however, have not yet been identified, and little is known about their ecological significance to wetland environments. Using an approach of characterizing a recombinant CBM ( Cj Cel9A) from a brackish bivalve, Corbicula japonica , this work identified Cj Cel9A-CBM ʼ s cellulose-binding activity. Scatchard plot analysis in the study of Cj Cel9A-CBM binding to α -cellulose showed a high corresponding partitioning coefficient (K r ) of 20.33, indicating Cj Cel9A-CBM ʼ s high affinity for cellulose. In addition, this affinity tolerated a high ion concentration buffer system, consistent with C. japonica ʼ s adaption to brackish wetland environments. Moreover, immuno-scanning electron microscopy (immuno-SEM) suggested that Cj Cel9A-CBM binds to α -cellulose unevenly, which was further determined to be caused by its higher affinity for crystalline cellulose (Cellulose I, mostly seen in plant leaves). Together, these findings suggest that Cj Cel9A-CBM is capable of immobilizing its associated catalytic domain on environmental crystalline cellulose (i.e., fallen leaves) in wetland sediments. Most importantly, they could provide a reasonable answer to a question recognized broadly in wetland ecologists, namely, why many wetland sediments have constant cellulase activities, although the sediments are being washed almost every day.

Liquid crystallinity of (hydroxypropyl)cellulose (HPC) derivative in aqueous solution was examined to develop eco-friendly liquid-crystalline system. Bulky adamantoyl group (adamantyl ester) was introduced as a substituent on HPC, and the effects of the degree of adamantoyl substitution (DSAd), polymer concentration, and temperature on the chiroptical properties, especially coloration and turbidity, of the aqueous lyotropics were investigated by circular dichroism, CD, and ultraviolet–visible–near-infrared, UV–Vis–NIR, spectrophotometry. Adamantates of HPC (Ad- HPCs) with extremely low DSAd (< 0.1) were successfully synthesized by acylation of HPC with 1-adamantanecarbonyl chloride in tetrahydrofuran. Ad-HPCs of DSAd ≤ 0.08 were highly soluble in water, and the concentrated aqueous solutions formed a right-handed cholesteric liquid-crystalline phase to impart vivid reflective colorations. The cholesteric helical pitch P, comparable to the wavelength of maximal reflectance λmax, increased with increasing DSAd of Ad-HPC and with decreasing polymer concentration. Wide-angle X-ray diffractometry, WAXD, revealed that the increases of P were attributable to the decrease of the twist angle ϕ between adjacent thin nematic layers. The aqueous Ad-HPC lyotropics were phase-separated and became turbid at an elevated temperature of > ∼30°C. Such a lower critical solution temperature (LCST)-type phase separation behavior of the Ad-HPC/water system was also affected by the hydrophobic adamantoyl group; the observed cloud point Tc was shifted to lower temperature side with increase in DSAd, presumably due to the heightening of hydrophobic interactions between the solute Ad-HPCs in water.

Lignin content, composition, and linkage types were investigated in pear fruit cultivars and related species. Lignin content increased during early stages and then decreased toward ripening in the core and flesh of "Gold Nijisseiki" and "Alexandrine Douillard". The lignin content was highest at harvest in Chinese quince. Only trace amounts of lignin were detected in apple flesh. The lignin content was low in Japanese pears "Ohshu", "Hosui", and "Kosui", and the noncondensed lignin index was high in flesh. The lignin type was guaiacyl-syringyl (GS) in these pears and related species. The S/G ratio at harvest varied widely (0.75-2.64) and increased during early stages and remained constant toward harvest in "Gold Nijisseiki" and "Alexandrine Douillard". "Gold Nijisseiki" and "Alexandrine Douillard" were determined to be G- and S-lignin-rich types, respectively. β-Aryl ether, phenylcoumaran, and resinol interunit linkage types were detected among monolignol bonds, and β-Aryl ether units were the main linkages in the pear.