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In the current study, the effects of fermentation manners on the structure and immunomodulatory activity of polysaccharide in longan wine or vinegar were investigated. Compared to longan polysaccharide (CP1), polysaccharide in longan wine (CP2) or vinegar (CP3 and CP4) had smaller molecular weights, and was consisted of more mannose, arabinose, rhamnose, galactose and less glucose. After purification, the major fraction (P1-P4) was obtained from CP1-CP4, respectively. The structures and immunoregulatory activities of P1-P4 were characterized. Fermentation and purification were favorable to increase the immunoregulatory activities of P2-P4, which were contributed to their different structural features. The structure-activity relationship analysis indicated that molecular weight, mannose, rhamnose, glucuronic acid, glucose and arabinose were significantly associated with the cytokines secretion. Compared with other polysaccharides, P3 displayed better immunomodulatory activity due to its lower molecular weight, lower contents of rhamnose and glucose, and higher levels of mannose and arabinose by activating MAPK and PI3K/Akt signaling pathways.

Dendrobium officinale, which is a medicine food homology plant, contains many metabolites, especially polysaccharides and flavonoids. Unlike flowers and stems, which are the most frequently harvested organs for a variety of uses, leaves tend to be discarded. This study assessed main metabolites in leaves to identify the most appropriate timing of collection during harvest, which was divided into three stages (S1-S3: 8, 10, and 11 months after sprouting, respectively). Metabolomic and transcriptomic analyses of S1-S3 were performed. Water-soluble polysaccharides (WSPs), flavonoids and free amino acids (FAAs) were detected in leaves. WSPs decreased from S1 to S3 but flavonoids and some FAAs (e.g., phophoserine) increased from S1 to S2, then decreased from S2 to S3. In all three stages, mannose was the dominant monosaccharide among WSPs, followed by glucose. In S2, 35 flavonoids were identified, the most abundant being rutin, schaftoside and vitexin, while 34 FAAs were identified in all three stages, the most abundant being tyrosine, phosphoserine and alanine. A total of 2584, 3414 and 2032 differentially expressed genes (DEGs) were discovered in S1 vs S2, S1 vs S3 and S1 vs S3, respectively. Correlation analysis revealed that five DEGs (DoSUS, DoXYLA, DoFRK, DoGMP, and DoCSLA), two DEGs (DoDFR, and DoANS) and a single DEG (DoPGAM) were involved in the metabolism of WSPs, flavonoids and phosphoserine, respectively. The findings of this study lay a foundation for the commercial exploitation of metabolites in the harvested leaves of D. officinale, and the use of detected DEGs in applied genetic studies.

In the complex tumor microenvironment (TME), tumor-associated macrophages (TAMs) play an important role in immunosuppression and tumor growth; hence, tumor cells are no longer the only target during tumor treatment. However, how to simultaneously target both tumor cells and TAMs to effectively eliminate the tumor remains a challenge. Herein, based on the specific receptors for cancer cells and TAMs, we prepared bidirectional anisotropic palladium nanoclusters (Pd-HA+Pd-M@R NPs) to simultaneously target tumor cells and TAMs for enhancing the therapeutic effect. In these nanoclusters, the Pd-HA part was obtained by modifying hyaluronic acid (HA) on the surface of ultra-small Pd nanozymes that could target CT26 cells. Moreover, with the high peroxidase (POD) and catalase (CAT) activity of Pd nanozymes, Pd-HA NPs directly caused cancer cell death by producing H

Endo-β-N-acetylglucosaminidase (ENGase) is an enzyme that hydrolyzes the chitobiose core of N-glycans and is widely used for glycan analysis on glycoproteins and preparation of precursors for glycosylated compounds. While most of the ENGases that can hydrolyze complex-type glycans are derived from eukaryotes, their production by heterologous expression using Escherichia coli is insufficient, making the production process expensive. From an industrial perspective, there is a need for a less expensive enzyme with higher activity and stability. In this study, we identified a novel ENGase gene from a thermophilic fungus, Rhizomucor pusillus, and named it Endo-Rp. Characterization of the recombinant Endo-Rp showed that the enzyme had maximum hydrolytic activity at 60 °C and hydrolyzed high-mannose-type and biantennary complex-type glycans, but not (2,4)-branched triantennary complex-type or fucosylated glycans. Endo-Rp also hydrolyzed N-glycans attached to RNase B and human transferrin. In summary, we consider Endo-Rp to be a valuable enzyme in various scientific and industrial applications.

Xanthan gum is a naturally occurring polysaccharide obtained from Xanthomonas campestris. The xanthan gum backbone consists of β-d-glucose linked like in cellulose. The trisaccharide β-d-mannose-(1-4)-α-d-glucuronic acid-(1-2)-α-d-mannose is linked to O(3) position of every other glucose residue. Ketal bonds link pyruvic acid residues to approximately half of the terminal mannose residues. The terminal mannose residues also carry acetate groups. Xanthan gum is used as a thickening, stabilizing, or suspending agent in various applications, e.g., food, pharmaceutical, cosmetic, and petroleum extraction. The performance of xanthan gum is based on its macromolecular conformation and association in solution and at interfaces. In water, xanthan gum undergoes conformational transitions from helix to random coil, in response to stimuli such as pH, ionic strength, temperature, and shear. This review presents fundamental information on the behavior of xanthan gum in aqueous media, at conditions and in the presence of additives which are of interest to applications that benefit from viscosity changes such as in oil and gas extraction. Effects on xanthan gum aqueous solutions of pH, electrolytes, changes in temperature, and added natural polysaccharides or synthetic polymers are highlighted. Such information is useful in the formulation of products and the design of processes involving xanthan gum and related polysaccharide polymers.

Although mesoporous silica nanoparticles (MSNs) are widely used as anticancer drug carriers, unmodified MSNs induce off-target effects and at high doses, there are adverse effects of hemolysis because of the interaction with the silanol group on the surface and cells. In this study, we developed doxorubicin (DOX)-loaded MSNs coated with mannose grafted poly (acrylic acid) copolymer (DOX@MSNs-man-g-PAA) to enhance the hemocompatibility and target efficacy to cancer cells. This uniform nanosized DOX@MSNs-man-g-PAA showed sustained and pH-dependent drug release with improved hemocompatibility over the bare MSNs. The uptake of the DOX@MSN-man-g-PAA in breast cancer cells was significantly improved by mannose receptor-mediated endocytosis, which showed significant increasing intracellular ROS and changes in mitochondrial membrane potential. This formulation exhibited superior tumor-suppressing activity in the MDA-MB-231 cells inoculated mice. Overall, the present study suggested the possibility of the copolymer-coated MSNs as drug carriers for cancer therapy.

Background Tuberculosis (Tb) is a disease with worldwide presence and a major cause of death in several developing countries. Current diagnostic methodologies often lack specificity and sensitivity, whereas a long time is needed to obtain a conclusive result. Material and methods In an effort to develop better diagnostic methods, this study aimed at the discovery of a biomarker signature for Tb diagnosis using a Nuclear Magnetic Resonance based metabolomics approach. In this study, we acquired 1H NMR spectra of blood serum samples of groups of healthy subjects, individuals with latent Tb and of patients with pulmonary and extra-pulmonary Tb. The resulting data were treated with uni- and multivariate statistical analysis. Results/Conclusion Six metabolites (inosine, hypoxanthine, mannose, asparagine, aspartate and glutamate) were validated by an independent cohort, all of them related with metabolic processes described as associated with TB infection. The findings of the study are according with the WHO Target Product Profile recommendations for a triage test to rule-out active TB.

Oligomannose-type glycans on glycoproteins play an important role in the endoplasmic reticulum (ER)-protein quality control. Mannose trimming of the glycans triggers the ER-associated protein degradation pathway. In mammals, ER mannosyl-oligosaccharide 1,2-α-mannosidase 1 and three ER degradation -enhancing α-mannosidase-like proteins (EDEMs) are responsible for mannose trimming. However, the exact role of EDEMs as α-mannosidases in ERAD remains unclear. Here, we performed the biochemical characterization of EDEM3 using synthetic oligomannose-type glycan substrates. In vitro assays revealed that EDEM3 can convert an asparagine-linked M9 glycan to M8 and M7 glycans in contrast to glycine-linked M9 glycan, and the activity is enhanced in the presence of ERp46, a known partner protein of EDEM3. Our study provides novel insights into the enzymatic properties of EDEM3 and the use of artificial glycan substrates as tools to study ERAD mechanisms.

Polysaccharides coded as CP were extracted from Athyrium Multidentatum (Doll.) Ching and then fractionated into five fractions (FP-1, FP-2, FP-3, FP-4 and FP-5). A purified polysaccharide designated as FP-3-4 was prepared from FP-3 by Sephadex G-100 column chromatography. Chemical analysis disclosed that CP and these fractions were heteropolysaccharides and mainly composed of glucose, galactose, arabinose, mannose, rhamnose, xylose, fucose, ribose and uronic acid with different molar ratios. They presented different images of SEM. FP-3-4 was highly branched polymers with sixteen types of linkages. The in vitro immunomodulatory results stated that CP and these fractions could promote macrophage proliferation, enhance macrophage phagocytosis and increase the production of NO, TNF-α, IFN-γ, IL-1β, IL-6, IL-10 and IL-2, indicating remarkable immune enhancement activities. RNA sequencing analysis revealed that CP and FP-3 induced macrophage activation mainly through MAPK and alternative NF-κΒ signaling pathways via CD14/TLR4 and Dectin-2 receptors, which were verified by RT-qPCR and western blot.

In this study, a novel low molecular weight polysaccharide (named LMW-BSP) was extracted from Bletilla striata at 4 °C. The results of structural characteristics analysis showed that LMW-BSP was a 23 kDa neutral polysaccharide contained glucose and mannose at a molar ratio of 1.00:1.26. Structural investigations of the periodate oxidation studies, Smith-degradation as well as methylation were performed, and combined with 1D and 2D NMR spectroscopy, the main chain residues sequence of LMW-BSP was concluded to be: α-D-Manp-(1 → 3)-β-D-Manp-(1 → [4)-β-D-Glcp-(1]

A new type of acidic exopolysaccharide (AESP-II) was extracted and separated from the fermentation broth of Cordyceps militaris (C. militaris), which was further purified to elucidate its structural characteristics and immunological activity. AESP-II was confirmed to be an acidic pyranose with a molecular weight of 61.52 kDa, which consisted of mannose, glucuronic acid, rhamnose, galactose acid, N-acetyl-galactosamine, glucose, galactose and arabinose with a molar ratio of 1.07: 5.38: 1: 3.14: 2.23: 15: 6.09: and 4.04. Animal experiment results verified that AESP-II can significantly promote the proliferation of spleen T and B lymphocytes in mice with immune injury caused by cyclophosphamide (CTX). In particular, the promotion of B lymphocytes presented a dose-effect relationship. In addition, the levels of the cytokines IL-2, IL-4, and IFN-γ, which are mainly secreted by T lymphocytes, and immunoglobulin IgG, IgM and IgA, which are mainly secreted by B lymphocytes, were increased after AESP-II treatment. The above results suggest that fluid immunity is involved in the immunomodulatory function of AESP-II. Simultaneously, AESP-II was detected significantly to promote the phosphorylation expression of p38 kinase (p38), extracellular regulated protein kinases (ERK) and c-Jun N-terminal kinase (JNK) by Western blot, further suggesting that the activation of the MAPK signaling pathway mediates the immunoregulatory function of AESP-II.

High mannose has previously associated with insulin resistance and cardiovascular disease (CVD). Our objective is to establish whether mannose is associated with anatomical evidence of coronary artery disease (CAD).Plasma mannose concentrations were measured by liquid chromatography/tandem mass spectrometry in a discovery cohort (n = 513) and a validation cohort (n = 221) of carefully phenotyped individuals. In both cohorts CAD was quantitated using state-of-the-art imaging techniques (coronary computed coronary tomography angiography (CCTA), invasive coronary angiography and optical coherence tomography). Information on subsequent CVD events/death was collected. Associations of mannose with angiographic variables and biomarkers were tested using univariate and multivariate regression models. Survival analysis was performed using the Kaplan-Meier estimator.Mannose was related to indices of CAD and features of plaque vulnerability. In the discovery cohort, mannose was a marker of quantity and quality of CCTA-proven CAD and subjects with a mannose level in the top quartile had a significantly higher risk of CVD events/death (p = 3.6e-5). In the validation cohort, mannose was significantly associated with fibrous cap thickness 65 μm (odds ratio = 1.32 per each 10 μmol/L mannose change [95% confidence interval, 1.05-1.65]) and was an independent predictor of death (hazard ratio for mannose≥vs 84.6 μmol/L: 4.0(95%CI, 1.4-11.3), p = 0.006).The current data add novel evidence that high mannose is a signature of CAD with a vulnerable plaque phenotype, consistently across measures of severity of vessel involvement and independent of the traditional correlates of CVD, and that it is an independent predictor of incident adverse outcomes.

Lectins from plants of the Diocleinae subtribe often exhibit specificity towards mannose/glucose and derived sugars, with some plants also displaying a second lectin specific to lactose/GalNAc. Here, we present a novel lectin from Collaea speciosa, named CsL, that displays specificity for GlcNAc/glucose. The lectin was extracted from Collaea speciosa seeds and purified by a single chromatographic step on a Sephadex G-50 matrix. In solution, the lectin appears as a dimeric protein composed of 25 kDa monomers. The protein is stable at pH 7–8 and dependent on divalent cations. CsL maintained its agglutination activity after heating to 90 °C for 1 h. Glycan array studies revealed that CsL binds to N-glycans with terminal GlcNAc residues, chitobiose and chitotriose moieties. The partial amino acid sequence of the lectin is similar to that of some lactose-specific lectins from the same subtribe. In contrast to other ConA-like lectins, CsL is not toxic to Artemia. Because of its remarkably different properties and specificity, this lectin could be the first member of a new group inside the Diocleinae lectins.

The structural elucidation and investigation of the immunostimulatory effects of crude polysaccharides (ECPs), non-starch polysaccharides (ECPs-I), and deproteinated non-starch polysaccharides (ECPs-II) derived from finger millet (Eleusine coracana) were performed. The extracted ECPs, ECPs-I, and ECPs-II primarily comprised different levels of carbohydrate (82.9, 41.9 and 62.0%), protein (5.3, 38.4 and 22.0%) and uronic acid (0.5, 2.4 and 0.7%). Monosaccharide composition analysis showed that glucose (88.2 and 40.6) was the main sugar unit present in ECPs and ECPs-I, followed by galactose, arabinose, xylose, rhamnose, and mannose; however, ECPs-II contained galactose (42.2%) as a major unit. The average molecular weights of ECPs, ECPs-I, and ECPs-II were found to be 120, 78 and 43 kDa, respectively. The polysaccharides as well as non-starch polysaccharides did not show any toxic effects on RAW 264.7 cells. ECPs-II treatment significantly enhanced the activation of RAW 264.7 cells by inducing nitric oxide (NO) production, upregulating inducible nitric oxide synthase (iNOS) and various pro-inflammatory cytokines including interleukin (IL)-1β, IL-6, IL-10, and tumor necrosis factor alpha (TNF-α). Furthermore, the RAW 264.7 cells were activated after ECPs-II treatment via the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and mitogen-activated protein kinase signaling (MAPK) pathways induced by a cluster of differentiation 40 (CD40) expression. The structure of ECPs-II mainly consists of (1→3,4)-linked galactopyranosyl and (1→3,5) arabinopyranosyl.

Inflammatory osteolysis is usually linked to the activation of proinflammatory macrophage and the consequent excessive osteoclast formation. Emerging evidence indicates that agents or drugs targeting lipid metabolism in macrophages might be potential in the prevention and treatment of osteolysis. d -mannose, as a natural-existed metabolic regulator, exerts strong effects on attenuating osteopenia and inflammation. However, whether d -mannose is therapeutically effective on osteolysis and whether a metabolic mechanism counts for the effect remain to be addressed. Here, by using an in vivo lipopolysaccharide (LPS)-induced inflammatory osteolysis mouse model as well as an in vitro LPS-induced inflammatory macrophage culture system, we show that d -mannose attenuates inflammatory osteolysis and inhibits excessive osteoclastogenesis by reversing the LPS-induced activation of proinflammatory macrophage. Mechanically, d -mannose recovers LPS-suppressed Cpt1a transcription and promotes lipid metabolism of macrophage. Treatment with etomoxir, an inhibitor of CPT1A, abolishes the effects of d -mannose on LPS-treated macrophage in vitro and eliminates its protection against osteolysis in vivo. Collectively, our results imply that d -mannose attenuates LPS-induced osteolysis by manipulating CPT1A-mediated lipid metabolism in macrophages. Our results disclose the unrecognized utilization of d -mannose as an effective intervention against inflammatory osteolysis and provide evidence to manage inflammatory scenarios by therapeutically targeting lipid metabolism in macrophage.

1,2-β-Mannobiose phosphorylases (1,2-β-MBPs) from glycoside hydrolase 130 (GH130) family are important bio-catalysts in glycochemistry applications owing to their ability in synthesizing oligomannans. Here, we report the crystal structure of a thermostable 1,2-β-MBP from Thermoanaerobacter sp. X-514 termed Teth514_1789 to reveal the molecular basis of its higher thermostability and mechanism of action. We also solved the enzyme complexes of mannose, mannose-1-phosphate (M1P) and 1,4-β-mannobiose to manifest the enzyme-substrate interaction networks of three main subsites. Notably, a Zn ion that should be derived from crystallization buffer was found in the active site and coordinates the phosphate moiety of M1P. Nonetheless, this Zn-coordination should reflect an inhibitory status as supplementing Zn severely impairs the enzyme activity. These results indicate that the effects of metal ions should be taken into consideration when applying Teth514_1789 and other related enzymes. Based on the structure, a reliable model of Teth514_1788 that shares 61.7% sequence identity to Teth514_1789 but displays a different substrate preference was built. Analyzing the structural features of these two closely related enzymes, we hypothesized that the length of a loop fragment that covers the entrance of the catalytic center might regulate the substrate selectivity. In conclusion, these information provide in-depth understanding of GH130 1,2-β-MBPs and should serve as an important guidance for enzyme engineering for further applications.

Glycoconjugates are involved in several pathological processes. Glycomimetics that can favorably emulate complex carbohydrate structures, while competing with natural ligands as inhibitors, are gaining considerable attention owing to their improved hydrolytic stability, binding affinity, and pharmacokinetic (PK) properties. Of particular interest are the families of α- d -mannopyranoside analogs, which can be used as inhibitors against adherent invasive Escherichia coli infections. Bacterial resistance to modern antibiotics triggers the search for new alternative antibacterial strategies that are less susceptible to acquiring resistance. In this review, we highlight recent progress in the chemical syntheses of this family of compounds, one of which having reached clinical trials against Crohn's disease (CD).

Background Prosopis juliflora is a clinically relevant allergic sensitizer worldwide and shares cross-reactivity with allergens from several tree pollen and food. The present study aims to purify and immunobiochemically characterize a major allergen from Prosopis pollen. The allergen was further investigated for its cross-reactivity with legume allergens. Methods Prosopis extract was fractionated by Q Sepharose and Superdex 75 gel filtration column to purify the allergen. Specific IgE against purified protein was estimated via ELISA and immunoblot. The protein was subjected to mass spectrometric analysis. Glycan characterization was performed by Schiff staining and lectin binding assay followed by deglycosylation studies. The functional activity of the purified protein was evaluated by the basophil activation test. Cross-reactivity was assessed by inhibition studies with legume extracts. Results A 35 kDa protein was purified and showed 75% IgE reactivity with the patients’ sera by ELISA and immunoblot. Glycan characterization of protein demonstrated the presence of terminal glucose and mannose residues. A reduction of 40% and 27% in IgE binding was observed upon chemical and enzymatic deglycosylation of the protein, respectively. The glycoprotein allergen upregulates the expression of CD203c on basophils which was significantly reduced upon deglycosylation, signifying its biological ability to activate the effector cells. The identified protein shared significant homology with Lup an 1 from the lupine bean. Immunoblot inhibition studies of the purified allergen with legume extracts underlined high cross-reactive potential. Complete inhibition was observed with peanut and common bean, while up to 70% inhibition was demonstrated with soy, black gram, chickpea, and lima bean. Conclusion A 35 kDa vicilin-like major allergen was isolated from P. juliflora. The protein possesses glycan moieties crucial for IgE binding and basophil activation. Furthermore, the purified protein shows homology with Lup an 1 and exhibits cross-reactivity with common edible legume proteins.

Immune checkpoint antibodies have emerged as novel therapeutics, while many patients are refractory. Researchers had identified tumor-associated macrophages (TAMs) is the pivotal factor involved in immune resistance and that manipulation of TAMs functions would improve the immunotherapies effectively. NF-κB pathway was one of the master regulators in TAMs manipulation. Inhibition of NF-κB pathway could achieve both re-polarization M2 TAMs and downregulation the expression of programmed cell death protein 1 (PD-1) ligand 1 (PD-L1) on TAMs to improve the effect of immunotherapies. Here, IMD-0354, inhibitor of NF-κB pathway was loaded in mannose modified lipid nanoparticles (M-IMD-LNP). Then, PD-1 antibody and M-IMD-LNP were co-loaded in matrix metalloproteinase 2 (MMP2) responsive and tumor target nanogels (P/ML-NNG). P/ML-NNG could co-deliver drugs to tumor site, disintegrated by MMP2 and release drugs to different targets. Evaluation of PD-1 expression, inhibition of NF-κB pathway, expression of PD-L1 on M2 TAMs and M2 TAMs re-polarization demonstrated that P/ML-NNG could block the PD-1/PD-L1 and NF-κB pathways simultaneously. Evaluation of CD4 + T cells, CD8 + T cells, Tregs, cytokines and antitumor immunity confirmed that IMD-0354 could improve the immunotherapies effectively. Those results provided forceful references for tumor immunetherapy.

Russula virescens is an edible wild mushroom that is widely distributed in south of China. This research aimed to analyze the structure characterization and evaluate the hypoglycemic, anticancer and immunological activities of two water soluble polysaccharides RVP-1 and RVP-2 from R. virescens. The results showed RVP-1 and RVP-2 were non-triple helix structured hetero-polysaccharides with different weight-average molecular weight 14,883 and 13,301 Da, respectively. Both RVP-1 and RVP-2 were composed of galactose, glucose, mannose and fructose, and the sugar residues were mainly linked by 1,6→, 1,2→, 1→ and 1,3,6→ glycosidic bonds. Moreover, the antidiabetic, anticancer and immune activities of RVP-1 and RVP-2 were explored in vitro methods. The two polysaccharides have potential for inhibiting α-glucosidase and α-amylase activities, suppressing HepG-2, A549 and MCF-7 cancer cells proliferation, and activating macrophage RAW 264.7 cells to secret immune cytokines for mediating cellular immune response. These findings provided a scientific basis for further utilization of polysaccharide from R. virescens.

Dendrobium officinale Kimura et Migo (D. officinale) is used as herbal medicine and new food resource in China, which is nontoxic and harmless, and can be used as common food. Polysaccharide as one of the main bioactive components in D. officinale, mainly composed of glucose and mannose (Manp: Glcp = 2.01:1.00-8.82:1.00), along with galactose, xylose, arabinose, and rhamnose in different molar ratios and types of glycosidic bonds. Polysaccharides of D. officinale exhibit a variety of biological effects, including immunomodulatory, anti-tumor, gastro-protective, hypoglycemic, anti-inflammatory, hepatoprotective, and vasodilating effects. This paper presents the extraction, purification, structural characteristics, bioactivities, structure-activity relationships and analyzes gaps in the current research on D. officinale polysaccharides. In addition, based on in vitro and in vivo experiments, the possible mechanisms of bioactivities of D. officinale polysaccharides were summarized. We hope that this work may provide helpful references and promising directions for further study and development of D. officinale polysaccharides.

In this study, two degraded polysaccharides were obtained by H2O2-Vc-ultrasonic and H2O2-Fe2+-ultrasonic treatment from Codium cylindricum. The basic structure of polysaccharides was characterized and the relationship between structure and antioxidant activity was studied. FTIR spectrum indicated that the degraded polysaccharides had similar functional groups (OH, CH, CO group) with ordinary polysaccharides. LC-MS analysis showed that the degraded polysaccharides were composed of the same monosaccharide units (mannose, galactose, arabinose, glucose, ribose) with Codium cylindricum polysaccharides, but the molar ratio was different. Meanwhile, the molecular weight and morphological feature of polysaccharides had been changed after degradation. Additionally, the antioxidant activity assay revealed that two degraded polysaccharides with lower molecular weight possessed better antioxidant property than ordinary polysaccharides. These results suggested that the basic structure of polysaccharides had not been damaged by two degradation methods, while the antioxidant activity was significantly enhanced.

Colon cancer (CRC) is the second leading cause of death and the third most diagnosed cancer worldwide. Although curcumin (CUR) has demonstrated a potent anticancer activity, it is characterized by its poor solubility, low bioavailability, and instability. This study is a projection from a previous investigation where CUR and succinylated CUR (CUR.SA) were separately encapsulated in mannosylated-chitosan nanoparticles (CM-NPs) to form CUR-NPs and CUR.SA-NPs, respectively. Here, we aim to assess the anti-CRC activity of these two nanoformulations. Cytotoxicity studies using CCK-8 assay indicated that both CUR-NPs and CUR.SA-NPs have a dose and time-dependent toxicity towards CRC human cell-lines (HCT116 and SW480), and more cytotoxic compared to free CUR or CUR-SA in a time-dependent manner. A significant induction of early and late apoptosis in the CUR-NPs and CUR.SA-NPs treated CRC cell lines compared to untreated cells was observed. Western blotting analyses confirmed the induction of apoptosis through activation of Caspase signaling compared to untreated cells. Based on the physicochemical properties of CUR-NPs and CUR.SA-NPs along with the data from the in vitro studies, we may conclude these nanoparticle formulations hold very promising attributes, worthy of further investigations for its role in the management of CRC. This work was funded by Qatar University Grant No IRCC-2021-006 .

A new immunoregulatory polysaccharide (DCP-W4) with a relative molecular mass of 1.37 × 104 Da was separated and purified from the stems of Dendrobium chrysotoxum under the guidance of immunoregulatory activity assay based on the small intestinal Peyer’s patch-mediated proliferation of bone marrow cells. Analysis of physicochemical features showed that DCP-W4 was a glucomannan consisting of glucose and mannose in a molar ratio of 3.0 : 1.0. Oral administration of mice suggested that DCP-W4 could significantly influence the body’s immune activity, which was evidenced by its ability to change the indexes of immune organs including spleen and thymus, the proliferation of bone marrow cells mediated by the supernatant of Peyer’s patch cells, the balance of Th1/Th2 through effectively regulating the secretion and ratio of IFN-γ and IL-4, the proportion and differentiation status of different immune cells including T-cells, dendritic cells and macrophages, and the production of sIgA as well as β-defensins and mucin-2 in the small intestine or in the spleen of mice. These results indicated that DCP-W4 was a polysaccharide with a hopeful potential for the modulation of intestine immune system and systemic immune system.

Carboxymethyl pachymaran (CMP) was prepared from Poria cocos polysaccharide by carboxymethylation. Two types of CMP (CMP-1 and CMP-2) were further purified by DEAE-52 anion-exchange chromatography. The structure characteristics and immunomodulatory activities of CMP-1 and CMP-2 were investigated. CMP-1 was determined as β-(1 → 3)-d-glucan. A β-(1 → 3)-d-glucan backbone structure was also found in CMP-2, which was mainly consistent of mannose and glucose, with the mole ratio of 0.03:1. The molecular weight of CMP-1 was 126.1 kDa with a 30.4 nm irregular sphere in distilled water. However, the molecular weight of CMP-2 was 172.6 kDa in a 19.9 nm spherical structure in water solution. Both CMP-1 and CMP-2 had triple helical structure, which can promote the proliferation and the phagocytosis of macrophages. Moreover, CMP-1 and CMP-2 both could improve the secretions of NO, TNF-α and IL-6 by increasing the expression of iNOS, TNF-α and IL-6 mRNA, but CMP-1 exhibited a stronger immunomodulatory ability than that of CMP-2. Our results indicated that CMP-1 and CMP-2 can act as potential immunomodulatory agents.

Cancer cells increase their metabolic activity by enhancing glucose uptake through overexpression of hexose transporters (Gluts). Gluts also have the capacity to transport other molecules besides glucose, including fructose, mannose, and dehydroascorbic acid (DHA), the oxidized form of vitamin C. The majority of research studies in this field have focused on the role of glucose transport and metabolism in cancer, leaving a substantial gap in our knowledge of the contribution of other hexoses and DHA in cancer biology. Here, we summarize the most recent advances in understanding the role that the multifunctional transport capacity of Gluts plays in biological and clinical aspects of cancer, and how these characteristics can be exploited in the search for novel diagnostic and therapeutic strategies.

The crude polysaccharide was extracted from A. asphodeloides rhizomes and further purified to produce two fractions F1 (50.0%) and F2 (19.6%). The chemical constitutions of the polysaccharides were neutral sugars (51.4%–89.7%), uronic acids (1.0%–30.2%) and sulfate esters (3.4%–8.1%), with various ratios of monosaccharides including rhamnose (1.4%–6.1%), arabinose (7.1%–21.2%), xylose (0.2%–4.8%), mannose (39.9%–79.0%), glucose (6.0%–11.1%) and galactose (2.6%–22.0%). The molecular properties of the polysaccharides were investigated by the HPSEC-UV-MALLS-RI system, revealing the Mw 130.0 × 103–576.5 × 103 g/moL, Rg 87.6–382.6 nm and SVg 0.3–54.3 cm3/g. The polysaccharides stimulated RAW264.7 cells to produce considerable amounts of NO and up-regulate the expression of TNF-α, IL-1 and COX-2 genes. Polysaccharides exhibited the growth inhibitory effects on cancer cells lines of AGS, MKN-28 and MKN-45, in which F2 fraction exhibited prominent bioactivities. The AGS cells treated with F2 experienced condensed cytoplasm, shrinkage of nucleus and chromatin marginalization with the highest number of cells at early-stage apoptosis reaching 54.6%. The inhibitory effect of F2 polysaccharide on AGS cells was through MAPKs and STAT3 signaling pathways. The backbone of the F2 was mainly linked by (1 → 4)-linked mannopyranosyl and (1 → 3)-linked galactopyranosyl. Taken together, the polysaccharide from A. asphodeloides rhizomes could be utilized as medicinal, pharmacological and functional food ingredients.

The preparation, chemical properties and bio-activities of polysaccharides derived from halophytes have gained an increasing interest in the past few years. Phytochemical and pharmacological reports have shown that carbohydrates are important biologically active compounds of halophytes with numerous biological potentials. It is believed that the mechanisms involved in these bio-activities are due to the modulation of immune system. The main objective of this summary is to appraise available literature of a comparative study on the extraction, structural characterizations and biological potentials, particularly immunomodulatory effects, of carbohydrates isolated from halophytes (10 families). This review also attempts to discuss on bioactivities of polysaccharides related with their structure-activity relationship. Data indicated that the highest polysaccharides yield of around 35% was obtained under microwave irradiation. Structurally, results revealed that the most of extracted carbohydrates are pectic polysaccharides which mainly composed of arabinose (from 0.9 to 72%), accompanied by other monosaccharides (galactose, glucose, rhamnose, mannose and xylose), significant amounts of uronic acids (from 18.9 to 90.1%) and some proportions of fucose (from 0.2 to 8.3%). The molecular mass of these pectic polysaccharides was varied from 10 to 2650 kDa. Hence, the evaluation of these polysaccharides offers a great opportunity to discover novel therapeutic agents that presented especially beneficial immunomodulatory properties. Moreover, reports indicated that uronic acids, molecular weights, as well as the presence of sulfate and unmethylated acidic groups may play a significant role in biological activities of carbohydrates from halophyte species.

The production, characterization and bioactivities of exopolysaccharides (EPSs) from a thermophilic bacterium Geobacillus sp. strain WSUCF1 were investigated. Using glucose as a carbon source 525.7 mg/L of exoproduct were produced in a 40-L bioreactor at 60 °C. Two purified EPSs were obtained: EPS-1 was a glucomannan containing mannose and glucose in a molar ratio of 1:0.21, while EPS-2 was composed of mannan only. The molecular weights of both EPSs were estimated to be approximately 1000 kDa, their FTIR and NMR spectra indicated the presence of α-type glycosidic bonds in a linear structure, and XRD analysis indicated a low degree of crystallinity of 0.11 (EPS-1) and 0.27 (EPS-2). EPS-1 and EPS-2 demonstrated high degradation temperatures of 319 °C and 314 °C, respectively, and non-cytotoxicity to HEK-293 cells at 2 and 3 mg/mL, respectively. In addition, both showed antioxidant activities. EPSs from strain WSUCF1 may expand the applications of microorganisms isolated from extreme environments and provide a valuable resource for exploitation in biomedical fields such as drug delivery carriers.

International audience; An exopolysaccharide (EPS) was purified from the probiotic bacterium Bacillus licheniformis AG-06 isolated from the polyherbal fermented traditional medicine (Ashwagandharishta) of Indian Ayurveda. High-performance liquid chromatography (HPLC) based compositional analysis exhibits the heteropolymeric nature of the EPS consisting of galactose, rhamnose, xylose, mannose, and glucose, as the monomeric units. Fourier-transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopic analyses confirm the presence of typical carbohydrate polymer functional groups and structural units, respectively. The purified EPS demonstrates the web-like fibrous and porous nature in scanning electron microscopic and atomic force microscopic studies. The purified EPS had shown 71.83% and 67.79% of flocculation and emulsification activities, respectively. Antioxidant activity was evaluated against 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), nitric oxide, and superoxide free radicals and the scavenging actions were increased in a dose-dependent manner. Moreover, the purified EPS exhibits a significant cytotoxic activity against the human lung carcinoma cells (A549), which strongly suggests the anticancer potential of the EPS derived from B. licheniformis AG-06.

Nowadays, microbial exopolysaccharide (EPS) have been extensively researched due to their multifunctional characteristics, especially the EPS from the lactic acid bacteria (LAB). However, the EPS from the Oenococcus oeni (O. oeni, a lactic acid bacteria commonly used in winemaking) have rarely been experimented. In this study, the EPS produced by O. oeni 28A-1 was obtained and characterized. The EPS had an average molecular weight of 7.73×104 Da and were composed of mannose, rhamnose, glucose, galactose, arabinose and galacturonic acid in a molar ratio of 13.6:1.3:8.8:5.6:1:1.4. The SEM images showed EPS appeared as irregular lamellar structure and coarse surface. The AFM image of the EPS showed that the irregular particle structure was dispersed in the solution, and some aggregation occurred in some areas. FT-IR analysis of the EPS revealed the characteristics of polysaccharide with the presence of specific functional groups. The EPS also exhibited higher thermal stability with a degradation temperature of 259.47°C in DSC analysis. In addition, the EPS from O. oeni exhibited great lyoprotective ability during its freeze-drying process, which indicated its great potential to be developed as natural lyoprotectant for O. oeni.

Background: Manno-oligosaccharides (MOS) is known as a kind of prebiotics. Mannanase plays a key role for the degradation of mannan to produce MOS. In this study, the mannanases of glycoside hydrolase (GH) families 5 Man5HJ14 and GH26 ManAJB13 were employed to prepare MOS from locust bean gum (LBG) and palm kernel cake (PKC). The prebiotic activity and utilization of MOS were assessed in vitro using the probiotic Lactobacillus plantarum strain. Results: Galactomannan from LBG was converted to MOS ranging in size from mannose up to mannoheptose by Man5HJ14 and ManAJB13. Mannoheptose was got from the hydrolysates produced by Man5HJ14, which mannohexaose was obtained from LBG hydrolyzed by ManAJB13. However, the same components of MOS ranging in size from mannose up to mannotetrose were observed between PKC hydrolyzed by the mannanases mentioned above. MOS stability was not affected by high-temperature and high-pressure condition at their natural pH. Based on in vitro growth study, all MOS from LBG and PKC was effective in promoting the growth of L. plantarum CICC 24202, with the strain preferring to use mannose to mannotriose, rather than above mannotetrose. Conclusions: The effect of mannanases and mannan difference on MOS composition was studied. All of MOS hydrolysates showed the stability in adversity condition and prebiotic activity of L. plantarum , which would have potential application in the biotechnological applications. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:8.0pt; mso-para-margin-left:0cm; line-height:107%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri",sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

A water-soluble glucose-rich polysaccharide from dried ‘Shixia’ longan pulp (LPsx) has been isolated for the first time, and its structure and immuno-regulatory mechanism were studied. LPsx is a hetero-polysaccharide with the average molecular weight 4102 g/mol. It was mainly consisted of glucose (95.9%), and small proportions of arabinose (2.1%), galactose (1.0%), mannose (0.6%), and xylose (0.4%). As analyzed by NMR, LPsx was mainly composed of (1 → 6)-α- d -glucose and (1 → 6)-β- d -glucose, branched with α- d -glucose-(1→. The immunomodulatory activity study showed that LPsx significantly increased the phagocytosis of macrophages, and strongly promoted the production of NO, IL-1β, IL-6 and TNF-α. Moreover, LPsx could inhibit the inflammatory response induced by lipopolysaccharide. The immuno-regulatory mechanism of LPsx was studied using RNA- sequencing and receptors activity analyses. It was found that LPsx induced macrophage activation via Ca2+ and CR3-mediated MAPKs and PI3K-AKT signaling pathways. The results would be helpful for revealing the health promoting mechanism of dried ‘Shixia’ longan in traditional Chinese medicine.

Intracellular methicillin-resistant Staphylococcus aureus (MRSA) is extremely difficult to remove by common antibiotics, leading to infection recurrence and resistance. Herein we report a novel exosome-based antibiotic delivery platform for eradicating intracellular MRSA, where mannosylated exosome (MExos) is employed as the drug carrier and preferentially taken up by macrophages, delivering lysostaphin (MExoL) and vancomycin (MExoV) to intracellular pathogens. Combination of MExoL and MExoV eradicated intracellular quiescent MRSA. Moreover, MExos rapidly accumulated in mouse liver and spleen, the target organs of intracellular MRSA, after intravenous (IV) administration. Thus, the MExos antibiotic delivery platform is a promising strategy for combating intracellular infection.

This study aimed to investigate the molecular characterization, antioxidant activity in vitro, cytotoxicity study of an exopolysaccharide isolated from Citrobacter freundii. Firstly, the culture conditions were standardized by the Design of experiments (DoE) based approach, and the final yield of thecrude exopolysaccharide was optimized at 2568 ± 169 mg L−1. One large fraction of exopolysaccharide was obtained from the culture filtrate by size exclusion chromatography and molecular characteristics were studied. A new mannose rich exopolysaccharide (Fraction-I) with average molecular weight ~ 1.34 × 105 Da was isolated. The sugar analysis showed the presence of mannose and glucose in a molar ratio of nearly 7:2 respectively. The structure of the repeating unit in the exopolysaccharide was determined through chemical and 1D/2D- NMR experiments as: Download : Download high-res image (71KB) Download : Download full-size image Finally, the antioxidant activity, and the cytotoxicity of the exopolysaccharide were investigated and the relationship with molecular properties was discussed as well.

Plant polysaccharides possess many health-promoting properties, which are closely related to the digestion, absorption and utilization of polysaccharides in the host. The characteristic changes in Chinese yam polysaccharide (CYP) during simulated gastrointestinal digestion and faecal fermentation, as well as the intestinal anti-inflammatory effects of CYP and fermented CYP, were studied. The molecular weight of CYP remained unchanged during gastrointestinal digestion. After 24 h of faecal fermentation, free glucose and mannose released from CYP were utilized by gut microbiota, and the production of short-chain fatty acids increased. Simultaneously, CYP improved the growth of Bifidobacterium and Megasphaera. Compared with CYP, faecal fermented CYP exhibited greater suppression of anti-inflammatory mediators and increased intestinal tight junction expression in LPS-stimulated coculture Caco-2/Raw264.7 cells. The obtained results reveal that the role of CYP in promoting gut health is closely related to the interactions between CYP and gut microbes, and CYP has potential as an anti-inflammatory adjuvant in enteritis therapy.

Dendrobium officinale is widely consumed owing to its numerous beneficial effects. We aimed to characterize polysaccharides of Dendrobium officinale (DOP) from the stems of Dendrobium officinale Xianhu 2 and clarify whether it benefit the intestinal microbiota and the immune system. The DOP weighed 291 kDa and comprised mannose, glucose, galactose, and rhamnose at 59.31:33.31:1.00:0.51 M ratio. In in vitro/vivo studies, DOP significantly increased benign intestinal microbe proportion (Lactobacillus, etc.), but reduced harmful bacteria (Escherichia_Shigella) (P 0.05), and significantly increased butyric acid production (P 0.05). Concentrations of 2 g/L DOP for in vitro fermentation and 100 mg/kg body weight for the mouse model were effective. In mice, DOP significantly reduced CRP, CD3, CD4, and TNF-α levels and increased C4 levels (P 0.05). DOP might influence the immune system indirectly through regulation of the gut microbiota. Its possible regulation mechanism was that DOP reduced CD4+ Th cells proliferation so that reduced the secretion of TNF-α.

Colorectal cancer (CRC) is one of the main causes of cancer-related deaths worldwide. Sporadic CRC develops from normal mucosa via adenoma to adenocarcinoma, which provides a long screening window for clinical detection. However, early diagnosis of sporadic colorectal adenoma (CRA) and CRC using serum metabolic screening remains unclear. The purpose of this study was to identify some promising signatures for distinguishing the different pathological metabolites of colorectal mucosal malignant transformation. A total of 238 endogenous metabolites were elected. We found that CRA and CRC patients had 72 and 73 different metabolites compared with healthy controls, respectively. There were 20 different metabolites between CRA and CRC patients. The potential metabolites of tumor growth (including patients with CRA and CRC) were found, such as A-d-glucose, D-mannose, N-acetyl-D-glucosamine, L-cystine, Sarcosine, TXB 2, 12-Hete, and chenodeoxycholic acid. Compared with CRA, 3,4,5-trimethoxybenzoic acid was significantly higher in CRC patients. There results prompt us to use the potential serum signatures to screen CRC as the novel strategy. Serum metabolite screening is useful for early detection of mucosal intestinal malignancy. We will further investigate the roles of these promising biomarkers during intestinal tumorigenesis in future. SIGNIFICANCE: CRC is one of the main causes of cancer-related deaths worldwide. Sporadic CRC develops from normal mucosa via adenomas to adenocarcinoma, which provides a long screening window for about 5-10 years. We adopt the metabolic analysis of extensive targeted metabolic technology. The main purpose of the metabolic group analysis is to detect and screen the different metabolites, thereby performing related functional prediction and analysis of the differential metabolites. In our study, 30 samples are selected, divided into 3 groups for metabolic analysis, and 238 metabolites are elected. In 238 metabolites, we find that CRA patients have 72 different metabolites compared with health control. Compared with health control, CRC have 73 different metabolites. Compared with CRA and CRC patients, there are 20 different metabolites. The annotation results of the significantly different metabolites are classified according to the KEGG pathway type. The potential metabolites of tumor growth stage (including patients with CRA and CRC) are found, such as A-d-glucose, D-mannose, N-acetyl-D-glucosamine, L-cystine, sarcosine, TXB 2, 12-Hete and chenodeoxycholic acid. Compared with CRA patients, CRC patients had significantly higher 3,4,5-trimethoxybenzoic acid level. It is prompted to use serum different metabolites to screen CRC to provide new possibilities.

Among posttranslational modifications, atypical arginine N-glycosylation has drawn increasing interest due to its fundamental role in various cellular procedures and signaling pathways. The efficient synthesis of arginine N-glycosylated substrates, as well as the generation of specific antibodies, remains challenging. This work describes the efficient synthesis of diverse arginine N-glycosylated peptides, in a process termed silver-promoted solid-phase glycosylation (SGG). There are two key features of the SSG strategy: (i) robust synthesis of gram-scale S-alkyl-isothiourea glycosyl donors facilitates the subsequent SSG procedure and (ii) the simultaneous introduction of both the side-chain sugar motif and arginine residue. Notably, our findings, combined with our previous results, provide a toolbox containing diverse S-alkyl-isothiourea glycosyl donors (glucose, galactose, mannose, ribose, xylose, lactose and maltose) as well as the corresponding Arg N-glycosylated peptides. In addition, our toolbox is shown to help investigate specific antibodies and identify multiple potent and precise biochemical tools for exploring arginine N-glycosylation.

The present study investigates the purification and characterization of mosquito larvicidal lectin from the seed kernel extract of Annona muricata and toxic effects on non-target organism Chironomus costatus. Soursop lectin was purified by anion-exchange column chromatography using DEAE-cellulose with approximately molecular mass of 260 kDa and with seven distinct subunits (16, 18, 21, 22, 24, 73 and 95 kDa). Soursop lectin highest Hemagglutination (HA) titer value of 128 was recorded against hen indicator RBC type with the influence of different divalent cations such as Ca2+, Ba2+ and Mn2+. The lectin mediated HA activity was highly inhibited by monosaccharides of glucose and mannose and disaccharides such as trehalose and melibiose. It was found to be EDTA sensitive (at 30 mM), pH-dependent (between 6–9) and heat-labile (upto 60 °C). A significant homology for soursop lectin was recorded to leguminous seed lectin from Psophocarpus scandens in MALDI-TOF-MS analysis with 66 % of sequence coverage. Finally, the toxicity bioassay of soursop lectin resulted in 100 % larval mortality for A. aegypti at 48 h whereas only 10 % mortality recorded to non-target organism C. costatus. Therefore, we concluded that soursop lectin could be a potent insecticidal agent in integrated pest management for controlling various insect pests.

An effective prophylactic HIV-1 vaccine is essential in order to contain the HIV/AIDS global pandemic. The discovery of different broadly neutralizing antibodies (bnAbs) in the last decades has enabled the characterization of several minimal epitopes on the HIV envelope (Env) spike, including glycan-dependent fragments. Herein, we provide a brief overview of the progress made on the development of synthetic carbohydrate-based epitope mimics for the elicitation of bnAbs directed to certain regions on Env gp120 protein: the outer domain high-mannose cluster and the variable loops V1V2 and V3. We focus on the design, synthesis and biological evaluation of minimal immunogens and discuss key aspects towards the development of a successful protective vaccine against HIV-1.

In order to increase content of glucuronic acid in the exopolysaccharide (EPS) and its flocculating activity, an UDP-glucose dehydrogenase gene was overexpressed in Lipomyces starkeyi V19. The obtained U9 strain could produce 62.1 ± 1.2 g/l EPS while the V19 strain only produced 53.5 ± 1.3 g/l EPS. The compositions of monosaccharides (mannose, glucuronic acid and galactose) in the purified EPS (U9-EPS) from the U9 strain contained 3.79:1:5.52 while those in the purified EPS (V19-EPS) were 3.94:1:6.29. The flocculation rate of the U9-EPS on kaolin clay reached 87.9%, which was significantly higher than that (74.7%) of the V19-EPS while the decolorization rate of Congo Red (CR) by the U9-EPS reached 94.3%, which was significantly higher than that of CR by the V19-EPS (86.23%). The results showed that the purified bioflocculant U9-EPS had effective flocculation of kaolin clay. The U9-EPS also had high ability to flocculate the polluted river water and decolorize Congo red.

Drug delivery to lungs via pulmonary administration offers potential for the development of new drug delivery systems. Here we fabricated the etofylline (ETO) encapsulated mannose-anchored N,N,N-trimethyl chitosan nanoparticles (Mn-TMC NPs). The prominent characteristics like biocompatibility, controlled release, targeted delivery, high penetrability, enhanced physical stability, and scalability mark Mn-TMC NPs as a viable alternative to various nanoplatform technologies for effective drug delivery. Mannosylation of TMC NPs leads to the evolution of new drug delivery vehicle with gratifying characteristics, and potential benefits in efficient drug therapy. It is widely accepted that following pulmonary administration, the introduction of mannose to the surface of drug nanocarriers provide selective macrophage targeting via receptor-mediated endocytosis. The fabricated Mn-TMC NPs exhibited particle size of 223.3 nm, PDI 0.490, and ζ-potential −19.1 mV, drug-loading capacity 76.26 ± 1.2%, and encapsulation efficiency of 91.75 ± 0.88%. Sustained drug release, biodegradation studies, stability, safety, and aerodynamic behavior revealed the effectiveness of prepared nanoformulation for pulmonary administration. In addition, the in vivo pharmacokinetic studies in Wistar rat model revealed a significant improvement in therapeutic efficacy of ETO, illustrating mannosylation a promising approach for efficient therapy of airway diseases following pulmonary administration.

GDP-mannose 3,5-epimerase (GM35E) catalyzes the double epimerization of GDP-mannose to yield GDP-l-galactose. GDP-l-gulose (C5-epimer) has previously been detected as a byproduct of this reaction, indicating that C3,5-epimerization occurs through an initial epimerization at C5. Given these products, GM35E constitutes a valuable bridge between d- and l-hexoses. In order to fully exploit this potential, the enzyme might be subjected to specificity engineering for which profound mechanistic insights are beneficial. Accordingly, this study further elucidated GM35E's reaction mechanism. For the first time, the production of the C3-epimer GDP-altrose was demonstrated, resulting in an adjustment of the acknowledged reaction mechanism. As GM35E converts GDP-mannose to GDP-l-gulose, GDP-altrose and GDP-l-galactose in a 72:4:4:20 ratio, this indicates that the enzyme does not discriminate between the C3 and C5 position as initial epimerization site. This was also confirmed by a structural investigation. Based on a mutational analysis of the active site, residues S115 and R281 were attributed a stabilizing function, which is believed to support the reactivation process of the catalytic residues. This paper eventually reflected on some engineering strategies that aim to change the enzyme towards a single specificity.

Recently, production of D-mannose becomes a hotspot owing to it exhibiting many physiological functions on people's health and wide applications in food and pharmaceutical field. The use of biological enzymes to production of D-mannose is of particular receiving considerable concerns due to it possessing many merits over chemical synthesis and plant extraction strategies. D-Lyxose isomerase (D-LIase) plays a pivotal role in preparation of D-mannose from d -fructose through isomerization reaction. Thus, a novel putative D-LIase from thermophiles strain Thermoprotei archaeon which was expressed in E. coli BL21(DE3) was first identified and biochemically characterized. The recombinant D-LIase showed an optimal temperature of 80 and 85 °C and pH of 6.5. It was highly thermostable at 70 °C and 80 °C after incubating for 48 h and 33 h, respectively, with retaining over 50% of the initial activity. A lower concentration of Ni2+ (0.5 mM) could greatly increase the activity by 25-fold, which was rare reported in other D-LIases. It was a dimer structure with melting temperature of 88.3 °C. Under the optimal conditions, 15.8 g L−1 of D-mannose and 33.8 g L−1 of D-xylulose were produced from 80 g L−1 of d -fructose and D-lyxose, respectively. This work provided a promising candidate sugar isomerase T. archaeon D-LIase for the production of D-mannose and D-xylulose.

This study aims to explore the production and physicochemical properties of an exopolysaccharide (EPS) produced from soil isolate, Paenibacillus sp. ZX1905 in submerged culture. The highest EPS production of 15.67 g/L was achieved in a medium containing soluble starch, peptone and inorganic salts. The purified EPS exhibited excellent skin lubricating properties and was named lubcan. The chemical analysis reviewed that lubcan was an acidic heteropolysaccharide consisted of glucuronic acid, glucose, mannose, galactose, and rhamnose in a molar ratio of 2:3:1:2:2, and the average molecular mass was about 3.27 × 106 Da. NMR and methylation analysis revealed that lubcan backbone was composed of 1,4-α-Man, 1,4,6-α-Glc, 1,3-α-Gal, 1,3-β-Rha, and 1,3-β-Gal, together with the branches of 1,3-α-Glc, 1,3-α-Rha, two 1,4-α-GlcA, and terminal-α-Glc(4,6-pyr). The lubcan solution exhibited stability at pH ranging from 5.0 to 7.0, temperature between 5 and 50 °C, and monovalent salts (0.2 M) and divalent salts (0.05 M) addition. The moisture absorption rates of lubcan were 16.98% and 40.41% under the conditions of 43% and 81% relative humidity, which were close to that of hyaluronic acid (17.28% and 41.20%, respectively). These properties make lubcan a good alternative to more expensive hyaluronic acid in the cosmetic industry.

A wheat germ polysaccharide (WGP-1) was isolated from wheat germ through hot-water (pH = 7.3) extraction and further fractionated by anion-exchange column using DEAE-52 cellulose column and purified by gel-permeation chromatography using Sephacryl S-500 column. WGP-1 was mainly consisted with rhamnose, arabinose, xylose, mannose, galactose and glucose, and linked with 1→, 1 → 2, 1 → 4, 1 → 3 and 1 → 6 glucosidic bands. The present study was designed to evaluate the antioxidant activities of WGP-1 in oleic acid (OA)-induced HepG2 cell model with its related mechanisms. Results showed that WGP-1 remarkably elevated the expression of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) and total antioxidant capacity (T-AOC), and decreased the levels of malondialdehyde (MDA) and reactive oxygen species (ROS) in OA-treated cell. WGP-1 was found to promote the expression of PI3K, the phosphorylation of AKT and the translocation of Nrf2, further increased the expression of HO-1 in OA-induced cells. These results demonstrate again that WGP-1 can effectively improve OA-induced oxidative damage, probably by up-regulating of PI3K expression, Nrf2 translocation, and AKT phosphorylation.

Selenium-enriched polysaccharides have been gaining great attention for their antitumor activity in recent years. In this study, a novel selenium polysaccharide fraction (Se-POP-3) produced by Pleurotus ostreatus was characterized and its antitumor activity explored at cellular level. Results showed that Se-POP-3 has 25.9 μg/g of selenium, an average molecular weight of 16,106 Da, and is mainly composed of mannose, glucose and galactose with a molar ratio of 1.7:49.6:2.4. Spectra analysis revealed Se-POP-3 as a pyranopolysaccharide linked by α-glycoside bonds in the main chain, and selenium may occur in the form of C O Se and Se O. A single sphere of Se-POP-3 has 50–60 nm in aqueous solution, even though it can agglomerate to form larger spherical structures. In vitro experiments with cancer and normal cell lines showed that Se-POP-3 can induce apoptosis and inhibit migration of cancer cells. Potential anticancer mechanism is that Se-POP-3 can disrupt the Bax/Bcl-2 protein ratio and inhibit the epithelial-to-mesenchymal transition (EMT) in cancer cells. Se-POP-3 showed no significant effect on the growth of normal cell lines. Se-POP-3 showed great potential as a broad-spectrum antitumor agent and dietary supplement.

Mannooligosaccharides (MOSs) are one of the most commonly used biomass-derived feed additives. The effectiveness of MOS varies with the length of oligosaccharides, medium length MOSs such as mannotetraose and mannopentaose being the most efficient. This study aims at improving specificity of β-mannanase from Aspergillus niger toward the desirable product size through rational-based enzyme engineering. Tyr 42 and Tyr 132 were mutated to Gly to extend the substrate binding site, allowing higher molecular weight MOS to non-catalytically bind to the enzyme. Hydrolysis product content was analyzed by high-performance anion-exchange chromatography with pulsed amperometric detection. Instead of mannobiose, the enzyme variants yielded mannotriose and mannotetraose as the major products, followed by mannobiose and mannopentaose. Overall, 42% improvement in production yield of highly active mannotetraose and mannopentaose was achieved. This validates the use of engineered β-mannanase to selectively produce larger MOS, making them promising candidates for large-scale MOS enzymatic production process.

In this study, the purification and characterization of a novel polysaccharide-based bioflocculant BM2 produced by a bacterium Bacillus megaterium strain PL8 with self-flocculating property were investigated. The results showed that BM2 was an acidic polysaccharide composed of Gal, GalUA, Glc, GlcUA and Man at a molar ratio of 45.1: 33.8:9.3:9.2:2.4, respectively. The molecular weight of BM2 was 4.55 × 106 Da. BM2 had high flocculation efficiencies across a wide pH ranged from 4 to 11 and a wide temperature ranged from 20 to 100 °C towards kaolin clay. BM2 was a cation-independent bioflocculant which could achieve high flocculation activity without the addition of other cations. Adsorption bridging was the main mechanism in the flocculation process of BM2 towards kaolin clay. The BM2 also displayed a high removal efficiency in terms of Congo red (88.14%) and Pb2+ ions (82.64%). These results suggested that BM2 had a great potential as an efficient bioflocculant candidate in wastewater treatment.