The influence of oxygen (0–50 bar) on the molar mass and composition of hemicelluloses after hydrothermal treatment of spruce chips was studied in a batch reactor setup at 130 °C–160 °C. Purified ...galactoglucomannan was studied as a reference. The dissolved oxygen enhanced significantly the depolymerization of hemicelluloses from over 15,000 g/mol to 180 g/mol (monomers) as well as promoted acids formation from the monosaccharides. About 2–3 times faster depolymerization was observed already with rather low amounts of oxygen (2–8 bar), while the kinetics of depolymerization was significantly slower in inert atmosphere. The decrease in pH from neutral to as low as 2.5 lead to an autocatalytic effect on the polysaccharide hydrolysis and the consecutive reactions of monosaccharides. The results emphasize the importance of performing hydrothermal treatment under inert atmosphere if large polymeric hemicellulsoses are desired or if monosaccharides are targeted in hydrolysis of hemicelluloses. If autocatalysis begins, it is difficult to stop.
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Eremurus Hissaricus (E.hissaricus) is a native plant of Tajikistan that has been used in traditional medicine and whose raw components have been identified as having potential for the domestic ...economy. We have found that carbohydrates comprise 80–85% of the root biomass, from which we have characterized two types of polysaccharides: A water-soluble polysaccharide (WSP) and an acid-soluble polysaccharide (ASP), with 23% and 8% yields, respectively. The results from FTIR, HPAEC-PAD, HPSEC, methylation linkage analysis and NMR spectroscopy (1H, 13C, zTOCSY, HSQC, HSQCTOXY and HMBC) demonstrated that WSP has a backbone of (1 → 4)-linked β-d-mannopyranosyl and β-d-glucopyranosyl residues in a 1.5:1 M ratio, having acetylated groups, with weight-average molecular weights of 495 kDa. Analyses of ASP indicate that it is comprised of d-galactose, d-mannose, and d-glucose in a molar ratio of 1.8: 1.6: 1.0, which is consistent with a branched galactoglucomannan polysaccharide with (1 → 4)-linked β-pyranose configurations, and weight-average molecular weight of 179 kDa. The FTIR absorption bands in the region of 875–890 cm 1 and NMR spectroscopy data confirm the presence of β-pyranose configuration of main polysaccharide backbone in the both ASP and WSP samples. These polysaccharides are an available raw material with the potential for use in a number of industrial applications.
The most widely-used wall materials for spray-dried microencapsulation have limitations in cost-effectiveness, health benefits and sustainability. Wood hemicelluloses, by-products of the forestry ...industry, including galactoglucomannans and glucuronoxylans have the potential to be utilized as innovative wall materials. This study investigated the applicability of galactoglucomannan and glucuronoxylan and their mixtures with carboxymethylcellulose as wall materials for microencapsulation of bilberry juice, in comparison to gum arabic. The results indicated that galactoglucomannan and glucuronoxylan have a relatively high anthocyanin encapsulation efficiency (71–73%), which was similar to that of gum arabic (76%). The addition of carboxymethylcellulose reduced the encapsulation efficiency of wood hemicelluloses to 46–54%. Microencapsulated powders prepared with wood hemicelluloses were considerably higher in total phenolic content and antioxidant activities than those prepared with gum arabic, and mixtures of wood hemicelluloses with carboxymethylcellulose. The results indicate that wood hemicelluloses are efficient wall materials for spray-dried microencapsulation of bioactive compounds.
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•Studied wood hemicelluloses included galactoglucomannan and glucuronoxylan.•Wood hemicelluloses are effective wall materials for spray drying of bilberries.•Encapsulation efficiency of galactoglucomannan and glucuronoxylan was 71–73%.•Adding carboxymethylcellulose reduced hemicelluloses' encapsulation efficiency.•Hemicelluloses added phenolic and antioxidant activities to their bilberry powders.
Eremurus Hissaricus (E.hissaricus) is a native plant of Tajikistan that has been used in traditional medicine and whose raw components have been identified as having potential for the domestic ...economy. We have found that carbohydrates comprise 80–85% of the root biomass, from which we have characterized two types of polysaccharides: A water-soluble polysaccharide (WSP) and an acid-soluble polysaccharide (ASP), with 23% and 8% yields, respectively. The results from FTIR, HPAEC-PAD, HPSEC, methylation linkage analysis and NMR spectroscopy (1H, 13C, zTOCSY, HSQC, HSQCTOXY and HMBC) demonstrated that WSP has a backbone of (1 → 4)-linked β-d-mannopyranosyl and β-d-glucopyranosyl residues in a 1.5:1 M ratio, having acetylated groups, with weight-average molecular weights of 495 kDa. Analyses of ASP indicate that it is comprised of d-galactose, d-mannose, and d-glucose in a molar ratio of 1.8: 1.6: 1.0, which is consistent with a branched galactoglucomannan polysaccharide with (1 → 4)-linked β-pyranose configurations, and weight-average molecular weight of 179 kDa. The FTIR absorption bands in the region of 875–890 cm 1 and NMR spectroscopy data confirm the presence of β-pyranose configuration of main polysaccharide backbone in the both ASP and WSP samples. These polysaccharides are an available raw material with the potential for use in a number of industrial applications.
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•Water- and acid-soluble polysaccharides were isolated from Eremurus Hissaricus roots.•FTIR and NMR spectroscopy analysis show β-d-pyranose configuration of the WSP&ASP.•The WSP contains glucomannan, while ASP is comprised of galactoglucomannan.•The NMR spectra clearly established the presence of acetyl groups in both polysaccharides.•The molecular weight of WSP and ASP determined by HPSEC was 495 kDa and 179 kDa.
•AZWSP extracted of yellow hawthorn fruit pulps.•The backbone of AZWSP was mainly composed of a β-d-Glucose and β-d-Mannose residues linked to side chains of α-d-galactose.•Interesting in vitro ...indigestibility, prebiotic and antioxidant activities.
The polysaccharide obtained from Crataegus azarolus fruit, by water extraction followed by ethanol precipitation and fractionation using copper complex, shows physiological activities: prebiotic and antioxidant. The total acid hydrolysis shows that the polysaccharide consists of galactose, glucose, mannose and rhamnose. The employed physico-chemical techniques of the polysaccharide sequences approach (FT-IR, MALDI-TOF-MS spectrometry, 1H and 13C NMR) indicate that it is a Galactoglucomannan, the main chain consists of major amounts of β-(1→4)-linked glucose and mannose residues with monosaccharide branches of α-(1→6) galactose and O-acetyl substituents. The properties of this new glucomannan suggest that it could find an application as a prebiotic in the food industry.
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Owing to their superior mechanical strength and structure similarity to the extracellular matrix, nanocelluloses as a class of emerging biomaterials have attracted great attention in ...three-dimensional (3D) bioprinting to fabricate various tissue mimics. Yet, when printing complex geometries, the desired ink performance in terms of shape fidelity and object resolution demands a wide catalogue of tunability on the material property. This paper describes surface engineered biomimetic inks based on cellulose nanofibrils (CNFs) and cross-linkable hemicellulose derivatives for UV-aided extrusion printing, being inspired by the biomimetic aspect of intrinsic affinity of heteropolysaccharides to cellulose in providing the ultrastrong but flexible plant cell wall structure. A facile aqueous-based approach was established for the synthesis of a series of UV cross-linkable galactoglucomannan methacrylates (GGMMAs) with tunable substitution degrees. The rapid gelation window of the formulated inks facilitates the utilization of these wood-based biopolymers as the feeding ink for extrusion-based 3D printing. Most importantly, a wide and tunable spectrum ranging from 2.5 to 22.5 kPa of different hydrogels with different mechanical properties could be achieved by varying the substitution degree in GGMMA and the compositional ratio between GGMMA and CNFs. Used as the seeding matrices in the cultures of human dermal fibroblasts and pancreatic tumor cells, the scaffolds printed with the CNF/GGMMA inks showed great cytocompatibility as well as supported the matrix adhesion and proliferative behaviors of the studied cell lines. As a new family of 3D printing feedstock materials, the CNF/GGMMA ink will broaden the map of bioinks, which potentially meets the requirements for a variety of in vitro cell–matrix and cell–cell interaction studies in the context of tissue engineering, cancer cell research, and high-throughput drug screening.
To avoid human health endangerment via the food chain, the investigation of Cd's effects on plant growth and development, and the discovery of various compounds that would mitigate the toxic effects ...of Cd, are essential. Galactoglucomannan oligosaccharides (GGMOs) are biologically active compounds, which improve the growth and development of plants. Therefore, the impact of GGMOs on the mitigation of Cd toxicity on maize (Zea mays L.) protoplasts was the main objective of this research. Here, protoplast viability, de novo cell wall regeneration on protoplasts' surface and Cd-uptake by protoplasts were studied. To study the influence of different treatments over time, the protoplasts were sampled on various days during the 14-day-long cultivation. The medium containing 2,4-dichlorophenoxyacetic acid, 6-benzylaminopurine, and GGMOs in a 10−9 M concentration with a pH of 3.8 was found to be optimal for protoplast cultivation. The toxic effect of Cd2+, which was evident already on the 2nd day of cultivation, resulted in decreased protoplast viability, the de novo cell wall regeneration, and in increased Cd-uptake. However, the application of GGMOs on Cd-stressed protoplasts increased cell wall regeneration. Fully or partly regenerated cell walls decreased the uptake of Cd2+ through the plasma membrane and improved protoplast viability. This is the first study that confirmed that biologically active oligosaccharides promote cell wall regeneration on the protoplast surface in both non-stress and Cd-stress conditions.
•Auxin, cytokinin, and pH have substantial role in protoplast viability maintenance.•GGMOs increased the protoplast viability in both non- and Cd-stress conditions.•The cell wall regeneration was higher in the presence of GGMOs.•GGMOs decreased the uptake of Cd by maize protoplasts.•Decreased Cd uptake was related to the enhanced cell wall formation.
In the context of sustainability transition to effectively utilize renewable biopolymers in building functional materials, we report a dynamic reversible nanocomposite hydrogel via thiolated ...galactoglucomannan (GGMSH) and TEMPO-oxidized cellulose nanofibrils (T-CNF) by deploying a UV-triggered thiol-disulfide exchange reaction. By adjusting the compositional content of GGMSH, the viscoelastic properties of the hydrogel precursors are tuneable and the crosslinking degree of disulfide bonds in these hydrogels dictates their mechanical properties upon UV irradiation. The nanocomposite hydrogels of GGMSH/T-CNF demonstrate robust self-healing properties, attributed to the dynamically reversible disulfide bonds and strong hydrogen bonds between T-CNF and GGMSH. For the hydrogel system of GGMSH/T-CNF/bovine serum albumin (BSA), the swelling behaviour of nanocomposite hydrogels largely dominated the release of BSA out of the hydrogels, suppressing the effect of redox-responsive stimuli with the addition of glutathione. Still, the cytotoxicity test proved a low cytotoxicity of the nanocomposite hydrogel and provided promising reference value to exploit this class of natural polymer-based hydrogel systems in biomedical applications.
•Redox-responsive hydrogel is constructed with UV-triggered thiol-disulfide bonds in binary nanocomposite of T-CNF and GGMSH.•Bovine serum albumin (BSA) as an interactive nanofiller improved the mechanical characteristics of nanocomposite hydrogel.•GGMSH/T-CNF/BSA hydrogel possesses fast self-healing properties thanks to the thiol-disulfide exchange reaction.•GGMSH/T-CNF/BSA hydrogel supports an immediate release of laden protein and showed good cytocompatibility.
According to traditional Chinese medicine theory, Ganoderma lucidum (G. lucidum) presents certain effects for nourishing nerves and calming the mind. G. lucidum polysaccharides (GLPs) have various ...biological activities; however, the structural characterization and the structure-activity relationship in anti-neuroinflammation of GLPs needs to be further investigated. In this work, the crude polysaccharide GL70 exhibited a remarkable impact on enhancing the spatial learning and memory function, as well as reducing the anxiety symptoms of the lipopolysaccharide (LPS)-induced rat model of Alzheimer's disease (AD). A galactoglucomannan (GLP70-1-2) was isolated from GL70, and characterized by monosaccharide composition, partial acid hydrolysis, methylation, and NMR analysis. The backbone of GLP70-1-2 was →6)-α-D-glcp-(1 → 6)-β-D-galp-(1 → 6)-β-D-manp-(13 → 4)-α-D-Glcp-(1 → 6)-α-D-glcp-(1 → 2)-β-D-galp-(1 → 4)-α-D-glcp-(1 → 6)-β-D-manp-(1 → 2)-β-D-galp-(12 → 6)-β-D-glcp-(1 → 6)-β-D-glcp-(1→ with two side chains attached to O-4 of →6)-β-D-galp-(1→ and O-3 of →6)-β-D-glcp-(1→, respectively. In addition, GLP70-1-2 exhibited remarkable efficacy in decreasing the level of pro-inflammatory factors in LPS-activated BV2 cells through the TLR4/MyD88/NF-κB pathway. Collectively, GLP70-1-2 exhibited significant anti-neuroinflammatory activity and may have the potential for developing as a drug for AD.
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