Search Results (177)

Fermented milk represents an excellent carrier for probiotics, and the incorporation of different carbon sources during fermentation can profoundly affect microbial metabolism. Based on our previous finding that Lactobacillus helveticus DYNDL_20-5 produces fucose-containing exopolysaccharides (EPS), we hypothesized that fucose supplementation could further enhance its metabolic activity and improve fermented milk quality. Thus, this study systematically investigated the impact of culturing L. helveticus DYNDL_20-5 with fucose (CMF5) on the quality characteristics and metabolic profiles of fermented milk. Compared to the control group without fucose and L. helveticus (CM), the CMF5 group demonstrated that L. helveticus effectively utilized fucose to promote acid production, enhance the fermentation process, increase microbial abundance, and enrich beneficial genera. Furthermore, the CMF5 group exhibited significantly improved textural properties, including enhanced viscosity and gel strength. Metabolomic analysis revealed that the addition of fucose and L. helveticus significantly influenced the metabolism of organic acids, fatty acids, and amino acids during milk fermentation, leading to increased concentrations of various metabolites associated with sensory quality, nutritional value, and health-promoting benefits. The findings of this study provide valuable insights into the synergistic effects of L. helveticus DYNDL_20-5 and fucose on fermented milk quality, offering a theoretical foundation for the development of novel functional dairy products with enhanced nutritional and sensory attributes. Full article

Shade stress is a crucial constraint on asparagus growth in intercropping and dense-planting systems. However, the physiological and molecular mechanisms linking shading intensity to sugar metabolism remain insufficiently understood. Herein, integrating newly generated physiological data with a targeted re-analysis of previously published omics datasets, we elucidated sugar metabolism responses in asparagus stems under different shading intensities (0%, 35%, 55%, and 75%). Moderate shading (55%) was associated with higher sucrose and fructose contents, together with increased activities of key sucrose metabolism enzymes, including sucrose synthase (SUS), soluble acid invertase (S-AI), and sucrose phosphate synthase (SPS), accompanied by differential changes in antioxidant enzyme activities (SOD, CAT and POD). Metabolomic analysis revealed a shift in carbon allocation under 55% shading, characterized by the accumulation of nucleotide sugars such as UDP-galactose and GDP-L-fucose. Transcriptomic analysis further indicated the enrichment of glycolysis/gluconeogenesis pathways under this shading condition, along with the upregulation of pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH) genes. Collectively, rather than merely confirming known shading responses, these findings provide new empirical evidence that asparagus stems actively reprogram their energy homeostasis and invoke alternative carbon partitioning pathways specifically at a 55% shading threshold. Full article

In this study, the structure of Walnut green husk polysaccharides (WGHP) and their effects on immune checkpoint inhibitor induced colitis (ICIIC) and intestinal microbiota in mice were studied. The results showed that WGHP was composed of mannose (Man) 0.56%, rhamnose (Rha) 6.81%, galacturonic acid (GalA) 53.52%, glucose (Glc) 8.93%, galactose (Gal) 13.94%, arabinose (Ara) 15.88% and fucose (Fuc) 0.35%. The results of animal experiments showed that the intake of WGHP could not only effectively improve the phenotype of ICIIC in mice, but also significantly regulate the composition of intestinal flora and the content of short-chain fatty acids in mice, such as regulating the ratio of Firmicutes/Bacterotoides, Lachnospiraceae NK4A136 group, Lactobacillus, and increasing the content of butyric acid, acetic acid, and isobutyric acid to restore intestinal homeostasis. In addition, WGHP improves inflammation in mouse ICIIC by inhibiting the secretion of pro-inflammatory cytokines TNF-α and IL-1β, thereby activating the GPR43/PD-1/PD-L1 signaling pathway. Therefore, WGHP can be used as a functional polysaccharide for the prevention of ICIIC. Full article

The increasing volume of produced water (PW) generated by oil extraction activities has intensified the need for environmentally sustainable strategies that enable its reuse and valorization. Biotechnological approaches, particularly those involving the microbial production of value-added compounds, offer a promising route for transforming PW from an industrial waste into a useful resource. In this context, bacterial exopolysaccharides (EPS) have gained attention due to their diverse functional properties and applicability in bioremediation, bioprocessing and petroleum-related operations. This study evaluated the potential of Lelliottia amnigena to synthesize EPS using oilfield PW as a component of the culture medium in stirred-tank bioreactors. Three conditions were assessed: a control using distilled water (dW), PW diluted to 25% (PW25%) and dialyzed PW (DPW). Batch experiments were conducted for 24 h, during which biomass growth, EPS accumulation and dissolved oxygen dynamics were monitored. Post-cultivation analyses included elemental and monosaccharide composition, scanning electron microscopy and rheological characterization of purified EPS solutions. EPS production varied among treatments, with dW and DPW yielding approximately 9.6 g L⁻¹, while PW25% achieved the highest productivity (17.55 g L⁻¹). The EPS samples contained fucose, glucose and mannose, with compositional differences reflecting the influence of PW-derived minerals. Despite reduced apparent viscosity under PW25% and DPW conditions, the EPS exhibited physicochemical properties suitable for biotechnological applications, including potential use in fucose recovery, drilling fluids and lubrication systems in the petroleum sector. The EPS also demonstrated substantial adsorption capacity, incorporating salts from PW and contributing to contaminant removal. This study demonstrates that PW can serve both as a substrate and as a source of functional inorganic constituents for microbial EPS synthesis, supporting an integrated approach to PW valorization. These findings reinforce the potential of EPS-based bioprocesses as sustainable green technologies that simultaneously promote waste mitigation and the production of high-value industrial bioproducts. Full article

Brown algae produce structurally complex sulfated fucose-containing polysaccharides known as fucoidans. These compounds are slowly degraded by marine microorganisms, leading to their accumulation in marine sediments and contributing to long-term carbon sequestration. The enzymatic mechanisms underlying fucoidan degradation remain poorly understood. GH141 family enzymes are widely distributed among fucoidan-degrading bacteria, but their function remains hypothetical. It is assumed that during fucoidans degradation, they may act as α-L-fucosidases. We performed a biochemical and bioinformatic analysis of four recombinant enzymes, Wf141_1, Wf141_2, Wf141_3, and Wf141_4, of the GH141 family from the fucoidan-degrading cluster of the marine bacterium Wenyingzhuangia fucanilytica CZ1127^T. Sequence similarity network (SSN) and Conserved Unique Peptide Pattern (CUPP) analysis of the GH141 members revealed that the Wf141s enzymes are distant from previously characterized GH141 members and belong to separate SSN clusters and CUPP branches. All four enzymes exhibited endo-fucanase activity against (1→3;1→4)-α-L-fucoidans. Wf141_1 and Wf141_2 were characterized as sulfated (1→3;1→4)-α-L-fucan endo-1→4-α-L-fucanases (EC 3.2.1.212) with distinct substrate preferences: Wf141_1 preferred [→3-α-L-Fucp2S-1→4-α-L-Fucp2S-1→]_n fragments, whereas Wf141_2 favored [→3-α-L-Fucp2S-1→4-α-L-Fucp2,3S-1→]_n regions. Their specificity depends on structural differences in sugar-binding subsites that recognize sulfation patterns. These enzymes were classified as endo-1→4-α-L-fucanases (EC 3.2.1.212). These findings establish a previously uncharacterized fucoidan-degrading enzymatic function within the GH141 family. Full article

Azidophenylselenylation (APS) of glycals is a straightforward transformation for preparing phenylseleno 2-azido-2-deoxy derivatives, which are useful blocks in the synthesis of 2-amino-2-deoxy-glycoside-containing oligosaccharides. However, the previously developed APS methods employing the CH₂Cl₂ as solvent, Ph₂Se₂-PhI(OAc)₂ (commonly known as BAIB), and a source of N₃⁻ are still not universal and show limited efficiency for glycals with gluco- and galacto-configurations. To address this limitation, we revisited both heterogeneous (using NaN₃) and homogeneous (using TMSN₃) APS approaches and optimized the reaction conditions. We found that glycal substrates with galacto- and gluco-configurations require distinct conditions. Galacto-substrates react relatively rapidly, and their conversion depends mainly on efficient azide-ion transfer into the organic phase, which is promoted by nitrile solvents (CH₃CN, EtCN). In contrast, for the slower gluco-configured substrates, complete conversion requires a non-polar solvent still capable of azide-ion transfer, such as benzene. These observations were applied to the optimized synthesis of phenylseleno 2-azido-2-deoxy derivatives of d-galactose, d-glucose, l-fucose, l-quinovose, and l-rhamnose. Full article

The microbiota–gut–organ axis is widely recognized as a pivotal mediator of systemic health, primarily through gut-derived immune, metabolic, and inflammatory signaling. Fucoidans, a class of fucose-containing sulfated polysaccharides predominantly composed of L-fucose and exclusively found in brown seaweeds, have been demonstrated to modulate gut microbiota composition and function, resulting in the enrichment of beneficial bacteria and the suppression of harmful species. They enhance the production of beneficial metabolites, such as short-chain fatty acids and specific bile acids, while suppressing harmful metabolites, including lipopolysaccharide, thereby ameliorating organ damage via key mechanisms such as the mitigation of oxidative stress and inhibition of inflammatory responses. Furthermore, fucoidan supplementation was found to restore intestinal barrier integrity. Using disease models including Parkinson’s disease, alcoholic liver disease, diabetic kidney disease, and obesity, the mechanisms through which fucoidans ameliorate extraintestinal diseases via the microbiota–gut–organ axis were elucidated. Microbiota-dependent mechanisms have been confirmed via experimental approaches such as fecal microbiota transplantation and specific bacterial strain supplementation. Fucoidans represent promising prebiotic agents for the restoration of microbial ecology and the treatment of extraintestinal diseases, highlighting the need for further clinical investigation. Full article

Dendrobium moschatum neutral polysaccharide (DMP-NP) was isolated using a water extraction–ethanol precipitation method, followed by purification with DEAE-cellulose anion-exchange resin and a dextran gel column. The resulting DMP-NP1 exhibited a weight-average molecular weight of 16.23 kDa. The molar ratio of monosaccharides was as follows: glucose–mannose–galactose–fucose–rhamnose = 78.54:19.11:1.59:0.53:0.23, with a glucose-to-mannose ratio of 4.1:1. Infrared spectroscopic analysis revealed characteristic carbohydrate absorption peaks and confirmed the presence of pyranosidic linkages. NMR analysis revealed that DMP-NP1 possesses a backbone mainly formed by 1→4 glycosidic linkages, a small number of 1→6 branches, and O-acetyl substitutions at the C2 and C3 positions of mannose residues. In vitro experiments demonstrated that treatment with 0–20 μg/mL (0–1.23 μM) DMP-NP significantly enhanced the activities of catalase (CAT) and superoxide dismutase (SOD) in IPEC-J2 cells, along with upregulation of the corresponding antioxidant genes. Concurrently, DMP-NP reduced the secretion of key pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6, and downregulated the expression of genes associated with both antioxidant and inflammatory signaling pathways. Collectively, these findings indicate that DMP-NP not only prevents but also ameliorates LPS-induced inflammatory injury in intestinal epithelial cells, thereby providing a basis for the application of DMP-NP in intestinal inflammation mitigation. Full article

In the present study, seven previously undescribed resin glycosides, designated cusponins I-VII (1–7), together with one known analog (8), were isolated from the seeds of Cuscuta japonica, a traditional medicine used in China. Structural elucidation revealed them to be glycosidic acid methyl esters, generated through on-column methyl esterification of naturally occurring resin glycosides catalyzed by NH₂-functionalized silica gel. All isolates were characterized as either pentasaccharides or tetrasaccharides, incorporating D-glucose, L-rhamnose, or D-fucose units as the sugar residues. Notably, compounds 1 and 3–7 contained the uncommon aglycone, 11S-hydroxypentadecanoic acid. Bioactivity assessments demonstrated that compounds 1–4, 6 and 8 suppressed α-glucosidase activity, with IC₅₀ values between 8.02 and 71.39 μM. In addition, compounds 3 and 5 exhibited inhibitory effects on protein tyrosine phosphatase 1B (PTP1B), with IC₅₀ values of 14.19 ± 1.29 μM and 62.31 ± 8.61 μM, respectively, marking the first report of PTP1B inhibitory activity among resin glycosides. Enzyme kinetic analyses indicated that compound 2 acted as an uncompetitive α-glucosidase inhibitor (K_is = 3.02 μM), whereas compound 3 inhibited PTP1B via a mixed-type mechanism (Kᵢ = 24.82 μM; K_is = 64.24 μM). Molecular docking combined with molecular dynamics simulations suggested that compounds 2 and 3 interacted with α-glucosidase-pNPG and PTP1B, respectively, forming stable complexes with favorable binding free energies. Collectively, this study reported eight resin glycosides from C. japonica, seven of them newly identified, with compounds 2 and 3 highlighted as promising scaffolds for antidiabetic drug discovery. Full article

This study aimed to enhance the α-glucosidase inhibitory activity of Houttuynia cordata polysaccharide (HCP) and investigate the structure of derivatives. Under optimal conditions (amylase derived from Aspergillus oryzae loading of 15 U/mL, 60 °C, and pH 6.1), the enzymatic hydrolysates of HCP (EHCP) demonstrated significantly higher α-glucosidase inhibition than non-enzymatically treated HCP (NEHCP). At a 6 mg/mL concentration, the α-glucosidase inhibition rates of EHCP and NEHCP were 77.32% and 52.92%, respectively. Molecular weight analysis revealed that EHCP was a homogeneous polysaccharide of 338.7 kDa, lower than that of NEHCP (504.6 kDa). The monosaccharide composition was Galacturonic acid/Glucuronic acid/Galactose/Rhamnose/Mannose/Fucose/Xylose/Arabinose/Glucose = 77.42:3.78:8.04:2.12:3.16:2.48:0.75:0.17:2.08 molar ratio. Infrared and nuclear magnetic resonance analyses confirmed pyranose rings and both α- and β-glycosidic linkages. Compared with NEHCP, EHCP demonstrated improved solubility, decreased crystallinity, and morphological changes from dense rod-like to loose flaky structures. Full article

Campylobacter jejuni is an enteric pathogen and a major cause of foodborne illness worldwide. It has been shown that C. jejuni primarily utilizes amino acids as its preferred energy source, but its ability to utilize L-fucose can grant a competitive advantage during intestinal colonization. In C. jejuni, fucose utilization is encoded by a variable region named plasticity region 2 (PR2); however, the regulatory mechanism for the region remains unknown and is investigated in this study. Genomic sequence analysis revealed that immediately upstream of the fucose utilization operon is a putative IclR-type transcriptional regulator, cj0480c (named fucR here). To determine whether fucR regulates the expression of the fucose utilization operon, we generated a knock-out mutant of fucR. RT-PCR and microarray analysis found that all the genes in the operon were polycistronic and significantly upregulated in the fucR mutant compared with their expression in the wild-type strain. In the presence of fucose, expression of the fucose utilization genes was induced in the wild-type strain but no longer inducible in the fucR mutant, suggesting that FucR functions as a repressor for the fucose utilization operon. To determine whether FucR directly or indirectly regulates the fucose utilization operon, a 6xHis-tagged full-length FucR was produced in Escherichia coli, and the purified recombinant FucR was used in electrophoretic mobility shift assay, which demonstrated that FucR bound specifically to the promoter region of the fucose utilization operon. Together, these results indicate that the L-fucose utilization operon in C. jejuni is directly regulated by FucR, which functions as a transcriptional repressor and modulates the expression of the operon in response to fucose. Full article

L-fucose is a monosaccharide derived from brown algae and has potential applications as a functional food ingredient. Previous studies have reported that L-fucose reduces lipid accumulation in murine adipose tissue. Adipose tissue not only regulates energy metabolism but also functions as an endocrine organ involved in inflammation through the production and secretion of various adipokines. L-fucose is expected to exert anti-inflammatory effects and modulate adipokine secretion in adipocytes. In the present study, we investigated the anti-inflammatory effects of L-fucose in adipocytes. L-fucose significantly suppressed the expression of pro-inflammatory mediators and reduced the production of reactive oxygen species induced by inflammatory stimulation with a combination of lipopolysaccharide (LPS), tumor necrosis factor-⍺ (TNF-⍺), and interferon-γ (IFN-γ). These effects are likely mediated through the inhibition of key signaling pathways, including mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) pathways. Additionally, we found that L-fucose promoted the multimerization and secretion of high molecular weight (HMW) adiponectin, even under inflammatory conditions. Our results suggest that although L-fucose downregulates adiponectin expression, it contributes to the formation and/or stabilization of HMW adiponectin, which is functionally more relevant in anti-inflammatory and metabolic regulation. L-fucose thus holds promise as a functional food ingredient for mitigating inflammation in adipocytes. Full article

Ulcerative colitis (UC) is a chronic inflammatory bowel disease marked by disruption of the intestinal barrier and gut microbiota imbalance, leading to significant impairment in patient quality of life. This study investigated the therapeutic efficacy of a synbiotic formulation composed of purified fucoidan from bloom-forming Sargassum horneri and the probiotic Lactobacillus plantarum in a dextran sulfate sodium (DSS)-induced zebrafish model of UC. Polysaccharides from S. horneri were extracted using Celluclast-assisted extraction and fractionated via DEAE anion-exchange chromatography, resulting in six fucoidan fractions. The sixth fraction (SH-F), with a molecular weight of 254 kDa, showed the highest fucose, sulfate contents, and demonstrated the highest effect on promoting L. plantarum growth. Structural analysis revealed that SH-F contained α-L-Fucp-(1→3), α-L-Fucp-(1→4), β-D-Galp-(1→2,3,4), α-L-Fucp-(1→3,4), and terminal α-L-Fucp residues where Fuc₁(SO₃)₁, Gal1Fuc₁(SO₃)₁, and Fuc₂(SO₃)₂ were the most common glycans. Synbiotic administration significantly attenuated DSS-induced colonic shrinkage, inhibited pro-inflammatory cytokines (IL-6, TNF-ɑ, and IL-1β), restored tight junction proteins (ZO-1, occludin), and downregulated the iNOS, COX2, and NF-κB signaling pathway in adult zebrafish. 16S rRNA gene sequencing revealed restoration of gut microbial diversity and increased abundance of beneficial bacterial taxa to improve DSS-induced UC. These findings highlight the potential synergistic effects of SH-F and L. plantarum as a combinatorial strategy to regulate gut inflammation and enhance epithelial barrier function, potentially offering new insights and therapeutic opportunities for UC intervention. Full article

α-L-fucosidases (EC 3.2.1.51) are of particular interest due to their ability to cleave terminal α-L-fucose residues from glycoconjugates, a property associated with numerous biological and therapeutic effects. They have also been investigated for their potential use in glycan remodeling, disease biomarker analysis, and particularly as therapeutic agents in the context of fucosidosis, a rare lysosomal storage disorder, caused by a deficiency in α-L-fucosidase activity. However, limitations in enzyme availability, stability, and substrate specificity highlight the need for novel and more efficient enzyme sources. Bifidobacterium castoris (B. castor is) is a newly identified species first discovered in the beaver gut microbiota in 2019. Phylogenetic studies have revealed its advanced metabolic capacity, and genomic analyses have demonstrated its extensive carbohydrate metabolism potential. This research article focuses on the recombinant production and biochemical characterization of a novel α-L-fucosidase from B. castoris LMG (Laboratorium voor Microbiologie Gent) 30937, predicted to belong to glycoside hydrolase family 29 (GH29) according to Universal Protein Resource (UniProt) annotation. Under optimized reaction conditions the recombinant α-L-fucosidase exhibited a specific activity of 0.264 U/mg to pNP-Fuc (4-Nitrophenyl-α-L-fucopyranoside). The results indicate that the enzyme is active in the pH range of 3.0–8.0 and temperatures of 24–42 °C, but its optimum conditions are the slightly acidic pH of 5.5 and the elevated temperature of 42 °C. This profile suggests that the enzyme is adapted to acidic intestinal-like environments. This novel enzyme expands the GH29 α-L-fucosidase repertoire and offers a promising new candidate for future biotechnological applications. Full article

In malignant-type gastric cancer, peritoneal dissemination is the most frequent metastatic process and is an inoperable condition for which effective treatment is lacking. Our research has revealed that galectin-4 plays an important role in the peritoneal metastasis of gastric cancer cells. Based on this, we hypothesized that inhibiting galectin-4 could suppress peritoneal metastasis. The inhibitory activity towards galectin-4 binding was evaluated using an enzyme-linked immunosorbent assay, while the suppressive effect on gastric cancer cell proliferation was assessed using an adenosine triphosphate-based cell viability assay. Direct binding to galectin-4 was examined by surface plasmon resonance analysis. Chemically synthesized fucoidan analogs exhibited significant suppressive activity against the proliferation of gastric cancer cells, partly via a galectin-4-mediated pathway. Among the 13 fucoidan analogs tested, analog 10, whose sugar chains composed of repeating 2,3-O-sulfated α(1,4)-linked L-fucose, showed significant inhibitory activity against galectin-4 binding and cell proliferation. 14, the cholestanol-conjugated analog 10, exhibited a pronounced increase in inhibitory activity, consistent with potential multimerization. Molecular docking and site-directed mutagenesis studies revealed that Arginine-45 in galectin-4 is important for binding to fucoidan analogs. In conclusion, fucoidan analogs with a strong affinity for galectin-4 are promising candidates for inhibiting the peritoneal metastasis of galectin-4-positive gastric cancer cells. Full article