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To enhance the use of wheat bran in chicken feed, a solid-state fermentation approach was used with Lactobacillus paracasei LAC28 and Pediococcus acidilactici BCC-1, along with arabinoxylan-specific degrading enzymes (xylanase, arabinofuranosidase, feruloyl esterase, XAF). The effects of the fermentation process were evaluated both in vitro and in vivo . In the in vitro study, XAF supplementation demonstrated superior performance, significantly reducing the pH of the fermented wheat bran (FWB) and increasing lactic, acetic, and butyric acid levels, total phenol content, and free radical scavenging capacity ( P < 0.05) compared to the XAF-free group. In the in vivo study, broilers were fed diets containing either unfermented wheat bran (UFWB) or FWB (fermented individually with LAC28 or BCC-1). Broilers fed FWB with BCC-1 exhibited significant improvements in body weight gain, intestinal morphology, and nutrient digestibility ( P < 0.05) compared to the control group. Moreover, the FWB established a healthier microbial community in the avian gastrointestinal tract. Overall, this study demonstrated the potential of combining XAF and bacteria to enhance wheat bran fermentation, benefiting broiler intestinal health and growth. This innovative approach holds promise as a cost-efficient and sustainable strategy to improve the nutritional quality of wheat bran for animal feed applications.

Exploring a novel natural cryoprotectant and understanding its antifreeze mechanism allows the rational design of future sustainable antifreeze analogues. In this study, various antifreeze polysaccharides were isolated from wheat bran, and the antifreeze activity was comparatively studied in relation to the molecular structure. The antifreeze mechanism was further revealed based on the interactions of polysaccharides and water molecules through dynamic simulation analysis. The antifreeze polysaccharides showed distinct ice recrystallization inhibition activity, and structural analysis suggested that the polysaccharides were arabinoxylan, featuring a xylan backbone with a majority of Ara f and minor fractions of Man p , Gal p , and Glc p involved in the side chain. The antifreeze arabinoxylan, characterized by lower molecular weight, less branching, and more flexible conformation, could weaken the hydrogen bonding of the surrounding water molecules more evidently, thus retarding the transformation of water molecules into the ordered ice structure.

Despite the potential of lignocellulose in manufacturing value-added chemicals and biofuels, its efficient biotechnological conversion by enzymatic hydrolysis still poses major challenges. The complex interplay between xylan, cellulose, and lignin in fibrous materials makes it difficult to assess underlying physico- and biochemical mechanisms. Here, we reduce the complexity of the system by creating matrices of cellulose, xylan, and lignin, which consists of a cellulose base layer and xylan/lignin domains. We follow enzymatic degradation using an endoxylanase by high-speed atomic force microscopy and surface plasmon resonance spectroscopy to obtain morphological and kinetic data. Fastest reaction kinetics were observed at low lignin contents, which were related to the different swelling capacities of xylan. We demonstrate that the complex processes taking place at the interfaces of lignin and xylan in the presence of enzymes can be monitored in real time, providing a future platform for observing phenomena relevant to fiber-based systems.

Bamboo is a promising biomass resource. However, the complex multilayered structure and chemical composition of bamboo cell walls create a unique anti-depolymerization barrier, which increases the difficulty of separation and utilization of bamboo. In this study, the relationship between the connections of lignin-carbohydrate complexes (LCCs) within bamboo cell walls and their multilayered structural compositions was investigated. The chemical composition, structural properties, dissolution processes, and migration mechanisms of LCCs were analyzed. Alkali-stabilized LCC bonds were found to be predominantly characterized by phenyl glycoside (PhGlc) bonds along with numerous p -coumaric acid (PCA) linkage structures. As demonstrated by the NMR and CLSM results, the dissolution of the LCC during the alkaline pretreatment process was observed to migrate from the inner secondary wall (S-layer) of the bamboo fiber cell walls to the cell corner middle lamella (CCML) and compound middle lamella (CML), ultimately leading to its release from the bamboo. Furthermore, the presence of H-type lignin-FA-arabinoxylan linkage structures within the bamboo LCC was identified with their primary dissolution observed in the S-layer of the bamboo fiber cell walls. The study results provided a clear target for breaking down the anti-depolymerization barrier in bamboo, signifying a major advancement in achieving the comprehensive separation of bamboo components.

Xylooligosaccharides (XOSs) gained much attention for their use in food and animal feed, attributed to their prebiotic function. These short-chained carbohydrates can be enzymatically produced from xylan, one of the most prevalent forms of hemicellulose. In this work, endo-1,4-β-xylanase from Thermotoga maritima was immobilized on cellulose-based beads with the goal of producing xylooligosaccharides with degrees of polymerization (DPs) in the range of 4-6 monomeric units. More specifically, the impact of different spacer arms, tethers connecting the enzyme with the particle, on the expressed enzymatic activity and oligosaccharide yield was investigated. After surface functionalization of the cellulose beads, the presence of amines was confirmed with time of flight secondary ion mass spectrometry (TOF-SIMS), and the influence of different spacer arms on xylanase activity was established. Furthermore, XOSs (DPs 2-6) with up to 58.27 mg/g xylan were obtained, which were greatly enriched in longer oligosaccharides. Approximately 80% of these XOSs displayed DPs between 4 and 6. These findings highlight the importance of topochemical engineering of carriers to influence enzyme activity, and the work puts forward an enzymatic system focusing on the production of longer xylooligosaccharides.

It was recently demonstrated by us that acetyl groups in oligosaccharides can migrate not only within one saccharide unit but also between two different saccharide units. Kinetics of this phenomenon were previously investigated in both mannan model compounds and a naturally occurring polysaccharide. In addition to mannans, there are also several other naturally acetylated polysaccharides, such as xyloglucans and xylans. Both xyloglucans and xylans are some of the most common acetylated polysaccharides in nature, displaying important roles in the plant cells. Considering the various biological roles of natural polysaccharides, it could be hypothesized that the intramolecular migration of acetyl groups might also be associated with regulation of the biological activity of polysaccharides in nature. Consequently, a better understanding of the overall migration phenomenon across the glycosidic bonds could help to understand the potential role of such migrations in the context of the biological activity of polysaccharides. Here, we present a detailed investigation on acetyl group migration in the synthesized xylan and glucan trisaccharide model compounds by a combination of experimental and computational methods, showing that the migration between the saccharide units proceeds from a secondary hydroxyl group of one saccharide unit toward a primary hydroxyl group of the other unit.

Corn bran is an abundant coprocessing stream of corn-starch processing, rich in highly substituted, diferuloyl-cross-linked glucurono-arabinoxylan. The diferuloyl cross-links make the glucurono-arabinoxylan recalcitrant to enzymatic conversion and constitute a hindrance for designing selective enzymatic upgrading of corn glucurono-arabinoxylan. Here, we show that two bacterial feruloyl esterases, wtsFae1A and wtsFae1B, each having a carbohydrate-binding module of family 48, are capable of cleaving the ester bonds of the cross-linkages and releasing 5-5', 8-5', 8-5' benzofuran, and 8- O -4' diferulate from soluble and insoluble corn bran glucurono-arabinoxylan. All four diferulic acids were released at similar efficiency, indicating nondiscriminatory enzymatic selectivity for the esterified dimer linkages, the only exception being that wtsFae1B had a surprisingly high propensity for releasing the dimers, especially 8-5' benzofuran diferulate, indicating a potential, unique catalytic selectivity. The data provide evidence of direct enzymatic release of diferulic acids from corn bran by newly discovered feruloyl esterases, i.e., a new enzyme activity. The findings yield new insight and create new opportunities for enzymatic opening of diferuloyl cross-linkages to pave the way for upgrading of recalcitrant arabinoxylans.

To enable its structural characterization by nuclear magnetic resonance (NMR) spectroscopy, the native structure of cereal water-unextractable arabinoxylan (WU-AX) is typically disrupted by alkali or enzymatic treatments. Here, WU-AX in the wheat flour unextractable cell wall material (UCWM) containing 40.9% ± 1.5 arabinoxylan with an arabinose-to-xylose ratio of 0.62 ± 0.04 was characterized by high-resolution solid-state NMR without disrupting its native structure. Hydration of the UCWM (1.7 mg H 2 O/mg UCWM) in combination with specific optimizations in the NMR methodology enabled analysis by solid-state 13 C NMR with magic angle spinning and 1 H high-power decoupling ( 13 C HPDEC MAS NMR) which provided sufficiently high resolution to allow for carbon atom assignments. Spectral resonances of C -1 from arabinose and xylose residues of WU-AX were here assigned to the solid state. The proportions of un-, mono-, and di-substituted xyloses were 59.2, 19.5, and 21.2%, respectively. 13 C HPDEC MAS NMR showed the presence of solid-state fractions with different mobilities in the UCWM. This study presents the first solid-state NMR spectrum of wheat WU-AX with sufficient resolution to enable assignment without prior WU-AX solubilization.

Wheat is the main ingredient of poultry diet, but its xylan has an adverse impact on poultry production. A novel xylanase from beef cattle rumen metagenome ( RuXyn ) and its effect on the wheat hydrolysis were investigated in the present study. The RuXyn coded for 377 amino acids and exhibited low identity (<40%) to previously reported proteins. The RuXyn was heterologously expressed in Escherichia coli and showed maximum activity at pH 6.0 and 40 °C. The activity of RuXyn could be increased by 79.8 and 36.0% in the presence of Ca 2+ and Tween 20, respectively. The soluble xylan and insoluble xylan in wheat could be effectively degraded by RuXyn and xylooligosaccharides produced accounting for more than 80% of the products. This study demonstrates that RuXyn has substantial potential to improve the application of wheat in poultry production by degrading wheat xylan and the accompanying xylooligosaccharides produced.

α-l-Arabinofuranosidase (Abf), a debranching enzyme that can remove arabinose substituents from arabinoxylan, promotes the hydrolysis of hemicellulose in plant biomass. However, the functional specificity of Abfs from different glycoside hydrolase (GH) families on the digestion of arabinoxylan and their synergistic interaction with xylanase have not been systematically studied. In this work, we characterized three Abfs (AxhA, AbfB, and AbfC) from GH62, GH54, and GH51 families in Aspergillus niger An76. Quantitative transcriptional analysis showed that expression of the axhA gene was upregulated as a result of induction by xylose substrates, whereas expression of the abfB gene was mainly induced by arabinose. Recombinant AxhA, AbfB, and AbfC exhibited different hydrolytic performances. AxhA showed the highest catalytic activity toward wheat arabinoxylan (WAX) and tended to hydrolyze monosubstituted arabinofuranose units, whereas AbfB had higher catalytic activity on AN and debranched arabinan (DAN), having the ability to cope with mono- and disubstituted arabinofuranose units. Furthermore, AbfC had greater arabinofuranosidase activity on p -nitrophenyl-α-l-arabinofuranoside ( p NP-AraF) than on other substrates. Moreover, three Abfs displayed obvious synergistic action with GH11 xylanase XynB against WAX and barley husk residues. The elucidation of the degradation mechanisms of Abfs will lay a theoretical foundation for the efficient industrialized transformation of arabinoxylans.

A novel enzyme Bi76 comprising GH10, E&#95;set&#95;Esterase&#95;N, and CE1 modules was identified, with the highest homology (62.9%) with a bifunctional endoxylanase/feruloyl esterase among characterized enzymes. Interestingly, Bi76 hydrolyzed glucan substrates besides xylans and feruloylated substrates, suggesting that it is the first characterized trifunctional endoxylanase/endoglucanase/feruloyl esterase. Analyses of truncation variants revealed that GH10 and E&#95;set&#95;Esterase&#95;N + CE1 modules encoded endoxylanase/endoglucanase and feruloyl esterase activities, respectively. Synergism analyses indicated that endoxylanase, α-l-arabinofuranosidase, and feruloyl esterase acted cooperatively in releasing ferulic acid (FA) and xylooligosaccharides from feruloylated arabinoxylan. The interdomain synergism of Bi76 overmatched the intermolecular synergism of TM1 and TM2. Importantly, Bi76 exhibited good capacity in producing FA, releasing 5.20, 4.38, 2.12, 1.35, 0.46, and 0.19 mg/g from corn bran, corn cob, wheat bran, corn stover, rice husk, and rice bran, respectively. This study expands the trifunctional endoxylanase/endoglucanase/feruloyl esterase repertoire and demonstrates the great potential of Bi76 in agricultural residue utilization.

A 6.2 m high immature bamboo ( Phyllostachys nigra ) was divided into seven fractions. The bamboo cell walls and lignin samples from young to old were characterized by 1 H- 13 C correlation heteronuclear single-quantum coherence (HSQC) nuclear magnetic resonance (NMR) spectroscopy both qualitatively and semiquantitatively. Mature bamboo and bamboo shoot samples were used as comparison references. HSQC-NMR analysis proved that cellulose and arabinoxylan have already deposited in bamboo shoot, and cellulose amount increased during growth. Lignin side chain linkage formation started from β-ether (β- O -4), then phenylcoumaran (β-5), and finally resinol (β-β). Ferulic acid and p -coumaric acid ( p CA) were formed at the earlier stages in the immature bamboo, and the p CA proportion decreased throughout the lignification process. We propose that the bamboo lignification process is distinct from both woody and other herbaceous plants, where syringyl units deposited at the early stage and polymerized with the β- O -4 linkage. Then guaiacyl units formed gradually, and finally, p -hydroxyphenyl units formed.

The high fiber content of cereal coproducts used in animal feed reduces the digestibility and nutrient availability. Therefore, the aim of this study was to elucidate the ability of two carbohydrase complexes to degrade the cell wall of wheat, maize, and rice during in vitro digestion. One complex was rich in cell-wall-degrading enzymes (NSPase 1), and the other was similar but additionally enriched with xylanases and arabinofuranosidases (NSPase 2). Degradation of arabinoxylan, the main cereal cell wall polysaccharide, was followed directly by gas-liquid chromatography (GLC) and indirectly through phenolic acid liberation as quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The effect was additionally visualized using a unique multispectral autofluorescence approach. Wheat fractions, in particular aleurone, were susceptible to degradation as judged from the redistribution of arabinoxylan (25% reduction in insoluble arabinoxylan), whereas the highest relative liberation of ferulic acid was observed in rice bran (6%). All cereal fractions, except for maize, had a higher release of ferulic acid with NSPase 2 than NSPase 1 (38% in rice and wheat bran, 30% in wheat whole grain, and 28% in wheat aleurone). Thus, the carbohydrase complexes were able to degrade important cell wall components during in vitro digestion but apparently through different mechanisms in wheat, maize, and rice.

Wheat bran is a major byproduct of the wheat industry and a rich source of cellulosic and hemicellulosic compounds. We developed a facile and reproducible method to generate functional nanomaterials from wheat bran derived polysaccharide, Arabinoxylan (AX). We first established that AX derived from wheat bran was chemically equivalent to commercially available AX extracted from wheat flour. Through facile chemical modification, positive and negatively charged domains were introduced along AX backbone, which in turn induced local electrostatic and hydrophobic interactions promoting the formation of nanoparticulate structures. The extracted, chemically modified AX was characterized using FTIR, 1 H NMR, and elemental analysis. We observed that, while both anionic and cationic AX self-assemble into stable, spherical nanoparticles with a low polydispersity index, the unmodified AX did not exhibit such self-organizational properties. To form functionally active nanomaterials, we further complexed negatively charged CRISPR-Cas9 DNA with cationic AX. Through gel electrophoretic studies, we identified that, at a feed ratio of DNA to AX of 1:15, AX is capable of forming polyplexes with DNA in the form of nanoparticles with an average hydrodynamic diameter of ∼100 nm and surface charge of -1.40 ± 0.91 mV. We envision that chemically modified AX, originally sourced from agricultural waste materials and not from food products, can be used as functional nanomaterials for gene delivery in the agrochemical sector thus catalyzing the circular approach of sustainability.

Interactions between gluten proteins and water-extractable arabinoxylan (WEAX) during the heating stage are crucial for the organoleptic quality of high-fiber cereal products. To reveal the molecular mechanism of WEAX on gluten characteristic upon heating, the current study comparatively investigated the effects of WEAX with different molecular weights ( M w ) on the heat-evoked conformational variation and polymerization behavior of gluten. Results showed that WEAX, especially low M w WEAX (L-WEAX), facilitated the polymerization ability of α-/γ-gliadins into glutenins, whereas high M w WEAX (H-WEAX) reduced the polymerizing temperature of glutenin and gliadin. L-WEAX could develop more hydrogen bonds with tyrosine of gluten and stabilize the secondary structure more evidently than H-WEAX upon heating. Compared with disulfide bridge formation, hydrophobic interactions were not the driving force involved in the heat-induced polymerization behavior affected by WEAX. WEAX evoked the reinforced glutenin network and heterogeneous distribution of gliadin, with a more uniform molecular surface developed for gluten.

Arabinoxylan oligosaccharides (AXOS) are a complex mixture of cereal derived, water-soluble prebiotics, obtained by enzymatic hydrolysis of arabinoxylan, a group of dietary fibers exerting numerous nutritional and health-beneficial effects. Such complex biomolecular mixtures are notoriously difficult to characterize without initial physical fractionation. Here we present the in situ analysis of AXOS using a variety of state-of-the-art sensitivity-enhanced 13 C-DOSY methods, enabling virtual separation and identification of the components. Three dimensional correlation plots displaying 13 C diffusivity (DOSY: Diffusion Ordered SpectroscopY), relaxation parameters (TOSY: raTe of relaxation Ordered SpectrscopY), and chemical shift offer a unique way to elucidate the composition of mixtures. We have demonstrated this multifaceted 13 C probed correlation strategy in standard mixtures of aliphatic and aromatic compounds, before implementing it on AXOS. These 3D-DOSY-TOSY plots in combination with 2D-NMR correlation experiments offer unprecedented clarity for assigning chemical functions, molecular size distribution, and dynamics of oligosaccharide mixtures.

Xylogucan (XG) fractions with different molar masses were prepared while preserving the natural structure of the XG. The solubility of the fractions was investigated using light scattering, chromatography, and microscopy techniques. The conformational changes of the XG molecules and their association and phase separation were investigated together with concentration and molar mass changes. The knowledge gained was then applied to investigate the interaction of different XG fractions at cellulose model surfaces using a quartz crystal microbalance with dissipation. The results indicate that there is a cluster formation and phase separation of the XG molecules at the cellulose/water interface induced by the increase in XG concentration close to the surface. Concomitantly, the adsorption regimes are altered for the XG fractions depending on the solubility properties, indicating that the insolubility, association, and phase separation of XGs in aqueous media affect their interaction with cellulose. The study is of vital importance for improving the functionality of sustainable materials made from xyloglucan/cellulose natural composites.

Multifunctional bioplastics have been prepared by amorphous reassembly of cellulose, hemicelluloses (xylan), and hydrolyzed lignin. For this, the biopolymers were dissolved in a trifluoroacetic acid-trifluoroacetic anhydride mixture and blended in different percentages, simulating those found in natural woods. Free-standing and flexible films were obtained after the complete evaporation of the solvents. By varying xylan and hydrolyzed lignin contents, the physical properties were easily tuned. In particular, higher proportions of hydrolyzed lignin improved hydrodynamics, oxygen barrier, grease resistance, antioxidant, and antibacterial properties, whereas a higher xylan content was related to more ductile mechanical behavior, comparable to synthetic and bio-based polymers commonly used for packaging applications. In addition, these bioplastics showed high biodegradation rates in seawater. Such new polymeric materials are presented as alternatives to common man-made petroleum-based plastics used for food packaging.

The present study aims to evaluate the effect of the growth conditions and the cultivar on the total and water-extractable (W-E) arabinoxylan (AX) in barley. For this purpose, nine barley varieties from two different years were analyzed. The total AX content ranged from 5.97 to 8.98 wt % d.m., while the W-E AX ranged from 0.06 to 0.35 wt % d.m. The W-E AX molecular properties were characterized by high-pressure size exclusion chromatography (HPSEC)-triple detector array (TDA). The molecular weight was between 2.3 × 10 5 and 12.6 × 10 5 Da, the polydispersity was between moderate and broad (1.1 < M w / M n < 4.3), and the conformation was a stiff semiflexible coil (0.5 < α < 1.3). The results indicate that the year influences the content of total AX and W-E AX and some molecular characteristics of W-E AX, such as its polydispersity and its conformation. Finally, the results demonstrated that the W-E AX can be used as an index of the malting attitude of barley because it positively correlates with germinative energy and kernel dimension.

Bacterial cellulose (BC) consists of a complex three-dimensional organization of ultrafine fibers which provide unique material properties such as softness, biocompatibility, and water-retention ability, of key importance for biomedical applications. However, there is a poor understanding of the molecular features modulating the macroscopic properties of BC gels. We have examined chemically pure BC hydrogels and composites with arabinoxylan (BC-AX), xyloglucan (BC-XG), and high molecular weight mixed-linkage glucan (BC-MLG). Atomic force microscopy showed that MLG greatly reduced the mechanical stiffness of BC gels, while XG and AX did not exert a significant effect. A combination of advanced solid-state NMR methods allowed us to characterize the structure of BC ribbons at ultra-high resolution and to monitor local mobility and water interactions. This has enabled us to unravel the effect of AX, XG, and MLG on the short-range order, mobility, and hydration of BC fibers. Results show that BC-XG hydrogels present BC fibrils of increased surface area, which allows BC-XG gels to hold higher amounts of bound water. We report for the first time that the presence of high molecular weight MLG reduces the density of clusters of BC fibrils and dramatically increases water interactions with BC. Our data supports two key molecular features determining the reduced stiffness of BC-MLG hydrogels, that is, (i) the adsorption of MLG on the surface of BC fibrils precluding the formation of a dense network and (ii) the preorganization of bound water by MLG. Hence, we have produced and fully characterized BC-MLG hydrogels with novel properties which could be potentially employed as renewable materials for applications requiring high water retention capacity (e.g. personal hygiene products).

The extensive characterization of glycosidic linkages in carbohydrates remains a challenge because of the lack of known standards and limitations in current analytical techniques. This study encompasses the construction of an extensive glycosidic linkage library built from synthesized standards. It includes an improved liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantitation of glycosidic linkages derived from disaccharides, oligosaccharides, and polysaccharides present in complicated matrices. We present a method capable of the simultaneous identification of over 90 unique glycosidic linkages using ultrahigh-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UHPLC/QqQ MS) operated in dynamic multiple reaction monitoring (dMRM) mode. To build the library, known monosaccharides commonly found in plants were subjected to partial methylation to yield partially derivatized species representing trisecting, bisecting, linear, and terminal structures. The library includes glycosidic linkage information for three hexoses (glucose, galactose, and mannose), three pentoses (xylose, arabinose, and ribose), two deoxyhexoses (fucose and rhamnose), and two hexuronic acids (glucuronic acid and galacturonic acid). The resulting partially methylated monosaccharides were then labeled with 1-phenyl-3-methyl-5-pyrazolone (PMP) followed by separation and analysis by UHPLC/dMRM MS. Validation of the synthesized standards was performed using disaccharide, oligosaccharide, and polysaccharide standards. Accuracy, reproducibility, and robustness of the method was demonstrated by analysis of xyloglucan (tamarind) and whole carrot root. The synthesized standards represent the most comprehensive group of carbohydrate linkages to date.

The molecular solubility of softwood arabinoglucuronoxylan (AGX) has been thoroughly investigated, and it has been shown that the chemical and physical structures of the extracted hemicellulose are not significantly influenced by different purification steps, but a transient molecular solubility of AGX was observed in aqueous media at low concentrations (1 g/L) when the dissolved macromolecules had a hydrodynamic diameter of up to 10 nm. A phase separation was detected when the concentration was increased to 15 g/L leading to an association of the smaller molecules into fractal structures with a considerably larger diameter, even though the dispersions were still transparent to ocular inspection. Dynamic Light Scattering and Cryo-Transmission Electron Microscopy showed dimensions in the range of 1000 nm. The phase separation of the sample was further characterized by estimating the χ-interaction parameter of AGX in water using the Flory-Huggins theory, and the results supported that water is a poor solvent for AGX. This behavior is crucial when films and hydrogels based on these biopolymers are made, since the association will dramatically affect barrier and mechanical properties of films made from these materials.

Model hemicellulose-cellulose composites that mimic plant cell wall polymer interactions were prepared by synthesizing deuterated bacterial cellulose in the presence of glucomannan or xyloglucan. Dilute acid pretreatment (DAP) of these materials was studied using small-angle neutron scattering, X-ray diffraction, and sum frequency generation spectroscopy. The macrofibril dimensions of the pretreated cellulose alone were smaller but with similar entanglement of macrofibrillar network as native cellulose. In addition, the crystallite size dimension along the (010) plane increased. Glucomannan-cellulose underwent similar changes to cellulose, except that the macrofibrillar network was more entangled after DAP. Conversely, in xyloglucan-cellulose the macrofibril dimensions and macrofibrillar network were relatively unchanged after pretreatment, but the cellulose I β content was increased. Our results point to a tight interaction of xyloglucan with microfibrils while glucomannan only interacts with macrofibril surfaces. This study provides insight into roles of different hemicellulose-cellulose interactions and may help in improving pretreatment processes or engineering plants with decreased recalcitrance.

This work aims at designing functional biomaterials through selective chemical modification of xylan from beechwood. Acidic hydrolysis of xylan led to well-defined oligomers with an average of six xylose units per chain and with an aldehyde group at the reductive end. Reductive amination was performed on this aldehyde end group to introduce an azide reactive group. "Click chemistry" was then applied to couple these hydrophilic xylans moieties with different hydrophobic fatty acid methyl esters that were previously functionalized with complementary alkyne functions. The resulting amphiphilic bio-based conjugates were then self-assembled using three different methods, namely, direct solubilization, thin-film rehydration/extrusion, and microfluidics. Well-defined micelles and vesicles were obtained, and their high loading capacity with propiconazole as an antifungal active molecule was shown. The resulting vesicles loaded with propiconazole in a microfluidic process proved to significantly improve the antifungal activity of propiconazole, demonstrating the high potential of such xylan-based amphiphiles.

Xylooligosaccharides (XOS) and arabinoxylooligosaccharides (AXOS) could be used to selectively favor growth of certain gut bacterial groups. The objective of this research was to understand how the structural differences of XOS and AXOS influenced the growth of Bacteroides species commonly found in the intestine. We report that the specific structural details of XOS and AXOS dictate the differential growth of Bacteroides species in the intestine. We also investigated the expression of two polysaccharide utilization loci (PULs) in a strain of Bacteroides ovatus upon growth on AXOS using three different susC transcripts as sentinel reporter genes. 2 3 -α-l-Arabinofuranosyl-xylotriose (A4) was shown to upregulate small xylan PUL gene expression, while 2 3 ,3 3 -di-α-l-arabinofuranosyl-xylotriose (A6) decreased expression of this PUL. These results reveal new details about the potentially very specific structure-function relationship of XOS and AXOS that could be used in targeted alteration of the microbial population in the gut through dietary interventions to maintain health.

Macromolecular dynamics in biological systems, which play a crucial role for biomolecular function and activity at ambient temperature, depend strongly on moisture content. Yet, a generally accepted quantitative model of hydration-dependent phenomena based on local relaxation and diffusive dynamics of both polymer and its adsorbed water is still missing. In this work, atomistic-scale spatial distributions of motional modes are calculated using molecular dynamics simulations of hydrated xyloglucan (XG). These are shown to reproduce experimental hydration-dependent 13 C NMR longitudinal relaxation times ( T 1 ) at room temperature, and relevant features of their broad distributions, which are indicative of locally heterogeneous polymer reorientational dynamics. At low hydration, the self-diffusion behavior of water shows that water molecules are confined to particular locations in the randomly aggregated XG network while the average polymer segmental mobility remains low. Upon increasing water content, the hydration network becomes mobile and fully accessible for individual water molecules, and the motion of hydrated XG segments becomes faster. Yet, the polymer network retains a heterogeneous gel-like structure even at the highest level of hydration. We show that the observed distribution of relaxations times arises from the spatial heterogeneity of chain mobility that in turn is a result of heterogeneous distribution of water-chain and chain-chain interactions. Our findings contribute to the picture of hydration-dependent dynamics in other macromolecules such as proteins, DNA, and synthetic polymers, and hold important implications for the mechanical properties of polysaccharide matrixes in plants and plant-based materials.

The arabinosyl side chains of grass arabinoxylans are partially acylated by p-coumarate ( pCA) and ferulate (FA). These aromatic side chains can cross-couple wall polymers resulting in modulation of cell wall physical properties. The determination of p-coumaroylated and feruloylated arabinose units has been the target of analytical efforts with trifluoroacetic acid hydrolysis the standard method to release feruloylated and p-coumaroylated arabinose units from arabinoxylans. Herein, we report on a more robust method to measure these acylated units. Acidolysis of extractive-free grass samples in a dioxane/methanol/aqueous 2 M HCl mixture provided the methyl 5- O- p-coumaroyl- and 5- O-feruloyl-l-arabinofuranoside anomers ( pCA-MeAra and FA-MeAra). These conjugates were readily analyzed by liquid chromatography combined with both UV and MS detection. The method revealed the variability of the relative acylation of arabinose units by pCA or FA in grass cell walls. This methodology will permit delineation of hydroxycinnamate acylation patterns in arabinoxylans.

As the main hemicellulose of poplar, the interaction of xylan with lignin was expected to have profound effect on biomass recalcitrance. In this paper, the dynamic changes of xylan and lignin in poplar cell wall during a mild pretreatment using γ-valerolactone (GVL) was investigated using chemical and microscopic techniques. Synergetic dissolution of branched xylan and lignin from the secondary wall of the fiber cell was found to play a major role in opening the cell wall structure for enzymatic attack. In the case of the removal of xylan and lignin reaching a certain level, β-O-4' cleavage of lignin which destroyed its interaction with hydrophobic cellulose face was found to make great contribution to the enhanced enzymatic hydrolysis. The deep understanding of this process could lead to a new insight into the understanding of the plant cell wall architecture and provide basic information for biomass processing.

A chemo-enzymatic pathway was developed to transform 4-O-methylglucuronic acid (MeGlcpA) containing xylo-oligosaccharides from beechwood into clickable monomers capable of polymerizing at room temperature and in aqueous conditions to form unique polytriazoles. While the gluco-oligosaccharide oxidase (GOOX) from Sarocladium strictum was used to oxidize C6-propargylated oligosaccharides, the acid-amine coupling reagents 1-ethyl-3-(3-(dimethylamino)propyl) carbodiimide (EDAC) and 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMT-MM) were employed and compared for their ability to append click functionalities to carboxylic acid groups of enzyme-treated oligosaccharides. While DMT-MM was a superior coupling reagent for this application, a triazine side product was observed during C-1 amidation. Resulting bifunctional xylo-oligosaccharide monomers were polymerized using a Cu(I) catalyst, forming a soft gel which was characterized by 1 H NMR, confirming the triazole product.

We report in this contribution that while low molecular weight hemicellulosic building blocks are known not to interact with cellulosic materials, their multivalent presentation on a polymeric scaffold significantly enhanced the binding interactions that are remarkably in the same range as those usually observed for lectin-carbohydrate interactions. We developed a poly(propargyl methacrylate) scaffold on which we conjugated, by "post-click" reaction, a variety of azide reducing-end functionalized xyloglucan oligosaccharides with controlled enzymatic-mediated rate of degalactosylation. Bottlebrush-like xyloglucan oligosaccharide glycopolymers (poly(XGO n )) were obtained and their self-assemblies in aqueous solution were investigated using dynamic light scattering (DLS). We demonstrated that increasing the extent of degalactosylation promoted self-association of poly(XGO n ), which we attribute to the appearance of hydrophobic domains. A sharp thermoresponsiveness, which corresponds to a decrease in aggregate size with increasing temperature, was observed when the extent of degalactosylation was 30% or greater. Importantly, isothermal titration calorimetry (ITC) and polarized/depolarized DLS revealed that poly(XGO n ) exhibit a significant capacity to interact with nanocrystalline cellulose (NCC) surfaces particularly for the nondegalactosylated form, emphasizing the important role of galactosyl residues in the binding mechanism and in the 3-dimensional structures of glycopolymers.

Byproducts from quinoa are not yet well explored sources of hemicellulose or products thereof. In this work, xylan from milled quinoa stalks was retrieved to 66% recovery by akaline extraction using 0.5 M NaOH at 80 °C, followed by ethanol precipitation. The isolated polymer eluted as a single peak in size-exclusion chromatography with a molecular weight of >700 kDa. Analysis by Fourier transform infrared spectroscopy and nuclear magnetic resonance (NMR) combined with acid hydrolysis to monomers showed that the polymer was built of a backbone of β(1 → 4)-linked xylose residues that were substituted by 4-O-methylglucuronic acids, arabinose, and galactose in an approximate molar ratio of 114:23:5:1. NMR analysis also indicated the presence of α(1 → 5)-linked arabinose substituents in dimeric or oligomeric forms. The main xylooligosaccharides (XOs) produced after hydrolysis of the extracted glucuronoarabinoxylan polymer by thermostable glycoside hydrolases (GHs) from families 10 and 11 were xylobiose and xylotriose, followed by peaks of putative substituted XOs. Quantification of the unsubstituted XOs using standards showed that the highest yield from the soluble glucuronoarabinoxylan fraction was 1.26 g/100 g of xylan fraction, only slightly higher than the yield (1.00 g/100 g of xylan fraction) from the insoluble fraction (p < 0.05). No difference in yield was found between reactions in buffer or water (p > 0.05). This study shows that quinoa stalks represent a novel source of glucuronoarabinoxylan, with a substituent structure that allowed for limited production of XOs by GH10 or GH11 enzymes.

This study investigated the effects of water-extractable arabinoxylan (WEAX) on gluten by thermal treatment. Fourier transform infrared spectroscopy (FTIR) results showed that heating significantly decreased β-sheets and β-turn structures in gluten proteins between 25 and 55 °C. The addition of WEAX caused a transition from β-turn to β-sheets at >55 °C. The ratio of weakly hydrogen-bonded β-sheets to strongly hydrogen-bonded β-sheets demonstrated an increasing trend with temperature increasing, but WEAX can hinder this process. FT-Raman results revealed that a hydrophilic environment was developed with 5% WEAX at 25 °C, and phenolic hydroxyl on ferulic acid can form new H-bonds with the phenyl groups of the nondissociated Tyr residues. A 5% WEAX content is helpful for gluten to maintain its original gauche-gauche-gauche conformation of disulfide bond upon heating. In addition, WEAX can reduce the elasticity of gluten and form a soft texture at 25, 55, and 75 °C.

Wheat arabinoxylan was treated with two α-arabinofuranosidases exhibiting different mode of action to create three different polymeric substrates. These three substrate preparations were characterized by xylopyranose backbone sugars that are (1) singly substituted by arabinose at C2 or C3, (2) doubly substituted by arabinose at C2 and C3, and (3) largely unsubstituted. All xylan preparations were grafted with glycidyl methacrylate using cerium ammonium nitrate and then evaluated in terms of graft yield and adsorption to cellulose surfaces. The highest graft yield was observed for the xylan preparation characterized by a largely unsubstituted xylopyranose backbone. Furthermore, QCM-D analyses revealed that grafted xylans exhibited a two-stage desorption pattern, which was not seen with the ungrafted xylans and was consistent with increased water sorption. Accordingly, this study demonstrates the potential of arabinofuranosidases to increase the yield and influence the viscoelastic properties of grafted xylans used as biobased cellulose coatings.

Lignocellulosic biomass is mainly constituted by cellulose, hemicellulose, and lignin and represents an important resource for the sustainable production of biofuels and green chemistry materials. Xylans, a common hemicellulose, interact with cellulose and often exhibit various side chain substitutions including acetate, (4-O-methyl) glucuronic acid, and arabinose. Recent studies have shown that the distribution of xylan substitutions is not random, but follows patterns that are dependent on the plant taxonomic family and cell wall type. Here, we use molecular dynamics simulations to investigate the role of substitutions on xylan interactions with the hydrophilic cellulose face, using the recently discovered xylan decoration pattern of the conifer gymnosperms as a model. The results show that α-1,2-linked substitutions stabilize the binding of single xylan chains independently of the nature of the substitution and that Ca 2+ ions can mediate cross-links between glucuronic acid substitutions of two neighboring xylan chains, thus stabilizing binding. At high temperature, xylans move from the hydrophilic to the hydrophobic cellulose surface and are also stabilized by Ca 2+ cross-links. Our results help to explain the role of substitutions on xylan-cellulose interactions, and improve our understanding of the plant cell wall architecture and the fundamentals of biomass pretreatments.

Green, all-polysaccharide based microcapsules with mechanically robust capsule walls and fast, stimuli-triggered, and switchable permeability behavior show great promise in applications based on selective and timed permeability. Taking a cue from nature, the build-up and composition of plant primary cell walls inspired the capsule wall assembly, because the primary cell walls in plants exhibit high mechanical properties despite being in a highly hydrated state, primarily owing to cellulose microfibrils. The microcapsules (16 ± 4 μm in diameter) were fabricated using the layer-by-layer technique on sacrificial CaCO 3 templates, using plant polysaccharides (pectin, cellulose nanofibers, and xyloglucan) only. In water, the capsule wall was permeable to labeled dextrans with a hydrodynamic diameter of ∼6.6 nm. Upon exposure to NaCl, the porosity of the capsule wall quickly changed allowing larger molecules (∼12 nm) to permeate. However, the porosity could be restored to its original state by removal of NaCl, by which permeants became trapped inside the capsule's core. The high integrity of cell wall was due to the CNF and the ON/OFF alteration of the permeability properties, and subsequent loading/unloading of molecules, could be repeated several times with the same capsule demonstrating a robust microcontainer with controllable permeability properties.

The cleavage of the C2-C3 bond in the building units of 1 → 4-linked polysaccharides by periodate formally results in two aldehyde units, which are present in several masked forms. The structural elucidation of such polysaccharide dialdehydes remains a big challenge. Since polysaccharide derivatives are increasingly applied in materials technology, unveiling the exact structure is of utmost importance. To address this issue for xylan, dialdehyde xylan (DAX, oxidation degree of 91.5%) has been synthesized as water-soluble polymer. The ATR-FTIR spectrum of DAX showed free aldehyde to be absent and exhibited a characteristic absorption at 858 cm(-1) related to hemiacetal groups. By a combination of 1D and 2D NMR techniques, it was confirmed that oxidized xylan is present as poly(2,6-dihydroxy-3-methoxy-5-methyl-3,5-diyl-1,4-dioxane). Based on GPC analysis, the DAX polymer shows a slightly lower molar mass (6.6 kDa) compared to the starting material (7.7 kDa) right after oxidation, and degraded further after one month of storage in 0.1 M NaCl solution (4.3 kDa). The oxidized xylan demonstrated lower thermal stability upon TGA analysis and a greater amount of residual char (20.6%) compared to the unmodified xylan (13.7%).

The temperature-dependence of xyloglucan (XG) adsorption onto smooth cellulose model films regenerated from N-methylmorpholine N-oxide (NMMO) was investigated using surface plasmon resonance spectroscopy, and it was found that the adsorbed amount increased with increasing temperature. This implies that the adsorption of XG to NMMO-regenerated cellulose is endothermic and supports the hypothesis that the adsorption of XG onto cellulose is an entropy-driven process. We suggest that XG adsorption is mainly driven by the release of water molecules from the highly hydrated cellulose surfaces and from the XG molecules, rather than through hydrogen bonding and van der Waals forces as previously suggested. To test this hypothesis, the adsorption of XG onto cellulose was studied using cellulose films with different morphologies prepared from cellulose nanocrystals (CNC), semicrystalline NMMO-regenerated cellulose, and amorphous cellulose regenerated from lithium chloride/dimethylacetamide. The total amount of high molecular weight xyloglucan (XGHMW) adsorbed was studied by quartz crystal microbalance and reflectometry measurements, and it was found that the adsorption was greatest on the amorphous cellulose followed by the CNC and NMMO-regenerated cellulose films. There was a significant correlation between the cellulose dry film thickness and the adsorbed XG amount, indicating that XG penetrated into the films. There was also a correlation between the swelling of the films and the adsorbed amounts and conformation of XG, which further strengthened the conclusion that the water content and the subsequent release of the water upon adsorption are important components of the adsorption process.

We present wetting, hygroscopicity, and interfacial activity of hemicellulose with respect to etherification and contrast it to their potential as interfacial modifiers, which is demonstrated by oil-in-water emulsification containing up to 60 vol% of the oil phase. Tunable amphiphilicity of hardwood and softwood hemicelluloses, xylans, and galactoglucomannans, respectively, was accomplished via controlled etherification. A series of degree of substitution (DS) of hydroxypropylated and 3-butoxy-2-hydroxypropylated ("butylated") grades was synthesized. The hemicellulose ethers were characterized by gel permeation chromatography, spectroscopic techniques, such as NMR, and contact angle measurements. An attenuated total reflectance infrared method was developed for fast identification of the DS. Near infrared analysis was utilized to explore the hygroscopicity of the material and to perform principle component analysis. The modification to butylated grades decreased the hygroscopicity, whereas the hydroxypropylated grades bound moisture. All of the hemicellulose ethers were water-soluble. The interfacial tension of the aqueous hemicellulose solutions was determined by pendant-drop tensiometer, and it was demonstrated to be dependent on the degree of modification.

Arabinoxylans are one group of dietary fiber components in cereal grains, and specific health benefits have been linked with their molecular fine structures and hence with physicochemical properties such as solubility in aqueous media. To characterize the fiber quality for functional foods, starchy endosperm and bran fractions from 11 durum wheat lines were analyzed for total and water-soluble arabinoxylans, (1,3;1,4)-β-glucan, and bound ferulic acid. The arabinoxylan contents ranged from 11 to 16.4% (w/w) in bran and from 1.5 to 1.8% in the starchy endosperm. Of the starchy endosperm arabinoxylans, 37% was soluble in water. No correlation was found between arabinoxylan content and bound ferulic acid in bran, although a relatively high level of this antioxidant was found in endosperm (38.3 μg/g endosperm flour). Enzymatic fingerprinting was performed to define the major fine structural features of arabinoxylans from both regions of the grain. Five major oligosaccharides released by xylanase hydrolysis were identified and characterized in the 11 durum lines. In addition, DP5, DP6, and DP7 oligosaccharides containing five, six, and seven pentosyl residues, respectively, were purified.

Native cellulose nanocrystals (CNCs) are valuable high quality materials with potential for many applications including the manufacture of high performance materials. In this work, a relatively effortless procedure was introduced for the production of CNCs, which gives a nearly 100% yield of crystalline cellulose. However, the processing of the native CNCs is hindered by the difficulty in dispersing them in water due to the absence of surface charges. To overcome these difficulties, we have developed a one-step procedure for dispersion and functionalization of CNCs with tailored cellulose binding proteins. The process is also applicable for polysaccharides. The tailored cellulose binding proteins are very efficient for the dispersion of CNCs due to the selective interaction with cellulose, and only small fraction of proteins (5-10 wt %, corresponds to about 3 μmol g(-1)) could stabilize the CNC suspension. Xyloglucan (XG) enhanced the CNC dispersion above a fraction of 10 wt %. For CNC suspension dispersed with carboxylmethyl cellulose (CMC) we observed the most long-lasting stability, up to 1 month. The cellulose binding proteins could not only enhance the dispersion of the CNCs, but also functionalize the surface. This we demonstrated by attaching gold nanoparticles (GNPs) to the proteins, thus, forming a monolayer of GNPs on the CNC surface. Cryo transmission electron microscopy (Cryo-TEM) imaging confirmed the attachment of the GNPs to CNC solution conditions.

Herein, we report a novel class of latex particles composed of a hemicellulose, xyloglucan (XG), and poly(methyl methacrylate) (PMMA), specially designed to enable a biomimetic modification of cellulose. The formation of the latex particles was achieved utilizing reversible addition-fragmentation chain transfer (RAFT) mediated surfactant-free emulsion polymerization employing XG as a hydrophilic macromolecular RAFT agent (macroRAFT). In an initial step, XG was functionalized at the reducing chain end to bear a dithioester. This XG macroRAFT was subsequently utilized in water and chain extended with methyl methacrylate (MMA) as hydrophobic monomer, inspired by a polymerization-induced self-assembly (PISA) process. This yielded latex nanoparticles with a hydrophobic PMMA core stabilized by the hydrophilic XG chains at the corona. The molar mass of PMMA targeted was varied, resulting in a series of stable latex particles with hydrophobic PMMA content between 22 and 68 wt % of the total solids content (5-10%). The XG-PMMA nanoparticles were subsequently adsorbed to a neutral cellulose substrate (filter paper), and the modified surfaces were analyzed by FT-IR and SEM analyses. The adsorption of the latex particles was also investigated by quartz crystal microbalance with dissipation monitoring (QCM-D), where the nanoparticles were adsorbed to negatively charged model cellulose surfaces. The surfaces were analyzed by atomic force microscopy (AFM) and contact angle (CA) measurements. QCM-D experiments showed that more mass was adsorbed to the surfaces with increasing molar mass of the PMMA present. AFM of the surfaces after adsorption showed discrete particles, which were no longer present after annealing (160 °C, 1 h) and the roughness (Rq) of the surfaces had also decreased by at least half. Interestingly, after annealing, the surfaces did not all become more hydrophobic, as monitored by CA measurements, indicating that the surface roughness was an important factor to consider when evaluating the surface properties following particle adsorption. This novel class of latex nanoparticles provides an excellent platform for cellulose modification via physical adsorption. The utilization of XG as the anchoring molecule to cellulose provides a versatile methodology, as it does not rely on electrostatic interactions for the physical adsorption, enabling a wide range of cellulose substrates to be modified, including neutral sources such as cotton and bacterial nanocellulose, leading to new and advanced materials.

Tomato is a known functional food due to its content of bioactive compounds. Herein, polysaccharides were extracted from mucilage of tomatoes, and a purified fraction (PTOK) was analyzed by sugar composition, methylation, and NMR spectroscopy analysis. The results showed the presence of an arabinoxylan, having (1→4)-linked β-d-Xylp units in the main chain, which carried a low proportion of branching (∼5.6%), at O-2 and O-3 position, with side chains constituted by single Araf or Xylp units. Intraperitoneal administration of the arabinoxylan in mice significantly reduced the number of abdominal constrictions induced by 0.6% acetic acid and the inflammatory phase of nociception induced by 2.5% formalin, indicating that it had an antinociceptive effect on inflammatory pain models, amplifying the biological role displayed by arabinoxylans in the diet. Furthermore, this study reports the presence of an arabinoxylan in a dicotyledon plant, and also it is the first study of polysaccharides from mucilage of tomatoes.

The phase diagram of mixtures of xyloglucan (XG) and amylopectin (AMP) in aqueous solution is presented. Water-in-water emulsions prepared from mixtures in the two-phase regime were studied in detail, and the interfacial tension was determined. It is shown that the emulsions can be stabilized by addition of β-lactoglobulin microgels (βLGm), but only at pH ≤ 5.0. Excess βLGm preferentially entered the AMP phase at pH > 5.0 and the XG phase at lower pH. The inversion was caused by adsorption of XG onto βLGm that started below pH 5.5. It is shown that modification of the surface of particles by coating with polysaccharides is a potential lever to control stabilization of water-in-water emulsions.

Cell wall material from whole oat grains was sequentially extracted to study the structural characteristics of individual arabinoxylan (AX) populations. Araf was singly substituted at both O-3 (mainly) and O-2 positions of Xylp, and no disubstitution of Xylp with Araf residues was found in oat AXs. Both highly substituted and sparsely substituted segments were found in AXs in Ba(OH)2 extracts, whereas AXs in 1 and 6 M NaOH extracts were rarely branched and easily aggregated. Both O-2-linked GlcA and 4-O-MeGlcA residues were present in oat AXs. A series of AX oligomers with galactose as a substituent was detected for the first time in oats. The present study suggested that the distribution of Araf was contiguous in oat AXs, different from the homogeneous distribution of Araf in wheat and barley AXs, which might result in different fermentation patterns in humans and animals.

Carbohydrate-binding modules (CBMs) are key components of many carbohydrate-modifying enzymes. CBMs affect the activity of these enzymes by modulating bonding and catalysis. To further characterize and study CBM-ligand binding interactions, neutron crystallographic studies of an engineered family 4-type CBM in complex with a branched xyloglucan ligand were conducted. The first neutron crystal structure of a CBM-ligand complex reported here shows numerous atomic details of hydrogen bonding and water-mediated interactions and reveals the charged state of key binding cleft amino acid side chains.

A major challenge of combinatorial therapy is the unification of the pharmacokinetics and cellular uptake of various drug molecules with precise control of the dosage thereby maximizing the combined effects. To realize ratiometric delivery and synchronized release of different drugs from a single carrier, a novel approach was designed in this study to load dual drugs onto the macromolecular carrier with different molar ratio by covalently preconjugating dual drugs through peptide linkers to form drug conjugates. In contrast to loading individual types of drugs separately, these drug conjugates enable the loading of dual drugs onto the same carrier in a precisely controllable manner to reverse multidrug resistance (MDR) of human hepatoma (HepG2) cells. As a proof of concept, the synthesis and characterization of xyloglucan-mitomycin C/doxorubicin (XG-MMC/DOX) conjugates were demonstrated. This approach enabled MMC and DOX to be conjugated to the same polymeric carrier with precise control of drug dosage. The cytotoxicity and combinatorial effects were significantly improved compared to the cocktail mixtures of XG-MMC and XG-DOX as well as the individual conjugate of the mixture. Moreover, the results also showed that there was an optimum ratio of dual drugs showing the best cytotoxicity effect and greatest synergy among other tested polymeric conjugate formulations.

Cranberry juice has been recognized as a treatment for urinary tract infections on the basis of scientific reports of proanthocyanidin anti-adhesion activity against Escherichia coli as well as from folklore. Xyloglucan oligosaccharides were detected in cranberry juice and the residue remaining following commercial juice extraction that included pectinase maceration of the pulp. A novel xyloglucan was detected through tandem mass spectrometry analysis of an ion at m/z 1055 that was determined to be a branched, three hexose, four pentose oligosaccharide consistent with an arabino-xyloglucan structure. Two-dimensional nuclear magnetic resonance spectroscopy analysis provided through-bond correlations for the α-L-Araf (1→2) α-D-Xylp (1→6) β-D-Glcp sequence, proving the S-type cranberry xyloglucan structure. Cranberry xyloglucan-rich fractions inhibited the adhesion of E. coli CFT073 and UTI89 strains to T24 human bladder epithelial cells and that of E. coli O157:H7 to HT29 human colonic epithelial cells. SSGG xyloglucan oligosaccharides represent a new cranberry bioactive component with E. coli anti-adhesion activity and high affinity for type 1 fimbriae.

To elucidate the influence of wood polysaccharide components on lignin formation in vitro, models for polysaccharide matrix in wood secondary cell wall were fabricated from two types of bacterial cellulosic films, flat film (FBC) and honeycomb-patterned film (HPBC), as basic frameworks by depositing xylan onto the films. An endwise type of dehydrogenative polymerization, "Zutropfverfahren", of coniferyl alcohol was attempted in the films with/without xylan. The resultant dehydrogenation polymer (DHP) was generated inside and outside xylan-deposited films, whereas DHP was deposited only outside the films without xylan. The amount of the generated DHP in the xylan-deposited films was larger than that in the films without xylan. The frequency of 8-O-4' interunitary linkage in DHP was also increased by the xylan deposition. These results suggest that xylan acts as a scaffold for DHP deposition in polysaccharides matrix and as a structure regulator for the formation of the 8-O-4' linkage. In addition, mechanical properties, i.e., tensile strength and modulus of elasticity (MOE), of both cellulosic films were found to be augmented by the deposition of xylan and DHP. Especially, DHP deposition remarkably enhanced MOE. Such effects of xylan on DHP formation and augmentation of mechanical strength were clearly observed for HPBC, revealing that HPBC is a promising framework model to investigate wood cell wall formation in vitro.

Improved moisture stability is desired in cellulose biocomposites. In order to clarify nanostructural effects, a new approach is presented where water and polymer matrix mobilities are characterized separately. Nanocomposites from cellulose nanofibers (CNF) in the xyloglucan (XG) biopolymer matrix are investigated at different hydration states. Films of XG, CNF, and CNF/XG composites are subjected to detailed (2)H and (13)C NMR relaxation studies. Since the (2)H NMR signal arises from heavy water and the (13)C signal from the polysaccharides, molecular water and polymer dynamics is for the first time investigated separately. In the neat components, (2)H transverse relaxation (T2) data are consistent with water clustering at the CNF fibril surfaces, but bulk spread of moisture in XG. The new method results in a description of water interaction with the nanoscale phases. At low hydration, water molecules at the CNF/XG interface exhibit higher water mobility than in neat CNF or XG, due to locally high water concentration. At the same time, CNF-associated interphase segments of XG show slower NMR-dynamics than that in neat XG.

In the process of gene mining for novel α-L-arabinofuranosidases (AFs), the gene Celf&#95;3321 from Cellulomonas fimi ATCC 484 encodes an AF, termed as AbfCelf, with potent activity, 19.4 U/mg under the optimum condition, pH 6.0 and 40 °C. AbfCelf can hydrolyze α-1,5-linked oligosaccharides, sugar beet arabinan, linear 1,5-α-arabinan, and wheat flour arabinoxylan, which is partly different from some previously well-characterized GH 51 AFs. The traditional substrate-specificity analysis for AFs is labor-consuming and money costing, because the substrates include over 30 kinds of various 4-nitrophenol (PNP)-glycosides, oligosaccharides, and polysaccharides. Hence, a preliminary structure and mechanism based method was applied for substrate-specificity analysis. The binding energy (ΔG, kcal/mol) obtained by docking suggested the reaction possibility and coincided with the experimental results. AbfA crystal 1QW9 was used to test the rationality of docking method in simulating the interaction between enzyme and substrate, as well the credibility of the substrate-specificity analysis method in silico.