Search Results (791)

A rational synthesis of the branched decaarabinofuranoside with 4-(2-azidoethoxy)phenyl aglycone (a Janus aglycone) related to the non-reducing terminal fragments of the arabinogalactan and lipoarabinomannan from Mycobacterium tuberculosis was proposed. Since the most challenging step is the formation of a 1,2-cis glycosidic linkage, we have significantly simplified access to a library of oligoarabinofuranosides derived from Mycobacterium tuberculosis polysaccharides using a silylated Ara-β-(1→2)-Ara disaccharide as the glycosyl donor. The application of a Janus aglycone also allowed us to reduce the number of reaction steps in glycoside synthesis. The obtained arabinans can be useful to further prepare conjugates as antigens for creating tuberculosis screening assays. Full article

The majority of studies of fungal utilization of chitosan are associated with the production of a specific enzyme, chitosanase, which catalyzes the hydrolytic cleavage of the macrochain. In our opinion, the development of approaches to obtaining materials with new functional properties based on non-destructive chitosan transformation by living organisms and their enzyme systems is promising. This study was conducted using a wide range of classical and modern methods of microbiology, biochemistry, and physical chemistry. The ability of the ascomycete Fusarium oxysporum Schltdl. to modify films of chitosan with average-viscosity molecular weights of 200, 450, and 530 kDa was discovered. F. oxysporum was shown to use chitosan as the sole source of carbon/energy and actively overgrew films without deformations and signs of integrity loss. Scanning electron microscopy (SEM) recorded an increase in the porosity of film substrates. An analysis of the FTIR spectra revealed the occurrence of oxidation processes and crosslinking of macrochains without breaking β-(1,4)-glycosidic bonds. After F. oxysporum growth, the resistance of the films to mechanical dispersion and the degree of ordering of the polymer structure increased, while their solubility in the acetate buffer with pH 4.4 and sorption capacity for Fe²⁺ and Cu²⁺ decreased. Elemental analysis revealed a decrease in the nitrogen content in chitosan, which may indicate its inclusion into the fungal metabolism. The film transformation was accompanied by the production of extracellular hydrolase (different from chitosanase) and peroxidase, as well as biosurfactants. The results obtained indicate a specific mechanism of aminopolysaccharide transformation by F. oxysporum. Although the biochemical mechanisms of action remain to be analyzed in detail, the results obtained create new ways of using fungi and show the potential for the use of Fusarium and/or its extracellular enzymes for the formation of chitosan-containing materials with the required range of functional properties and qualities for biotechnological applications. Full article

Biotechnological valorization of Flourensia cernua foliage was carried out using fungal solid-state fermentation; several outcomes of this bioprocess were identified which added value to the plant material. F. cernua leaves placed in aluminum trays were inoculated with Aspergillus niger; extracts of this plant were evaluated and the foliage was tested for in vitro digestibility. The solid bioprocess was carried out at 75% humidity for 120 h and after the fermentation, β-glucosidase activity; phenolics and in vitro digestibility were quantified and measured. Two high β-glucosidase production levels were detected at 42 and 84 h with 3192 and 4092 U/L, respectively. Several phenolics of industrial importance were detected with a HPLC-ESI-MS, such as glycosides of luteolin and apigenin. The other outcome was a substantial improvement in anaerobic digestibility. The unfermented sample registered a 30% in vitro degradability, whereas samples subjected to 84 h of fungal fermentation increased degradability by up to 51%. This bioprocess was designed to detect more than one product, which can contribute to an increase in the added value of F. cernua foliage. Full article

Opuntia humifusa (commonly known as Cheon-nyun-cho) has traditionally been used for its antioxidant, laxative, and immune-boosting properties, but its potential prebiotic activity remains largely unexplored. In this study, we evaluated the prebiotic potential of O. humifusa leaf and fruit extracts by assessing their effects on the growth of four Lactobacillus spp. strains. Among them, Lactobacillus paracasei KCTC 12576 exhibited the most pronounced response to the extracts and was therefore selected for further investigation. Comparative analysis demonstrated that ethanol extracts were more effective than water extracts, and leaf extracts outperformed fruit extracts in enhancing bacterial viability. Notably, the ethanol extract of O. humifusa leaves showed the strongest stimulatory effect on L. paracasei KCTC 12576 growth. Based on extraction optimization studies, 60% ethanol was identified as the most effective solvent for obtaining bioactive compounds. HPLC analysis revealed the presence of isorhamnetin 3-O-β-D-(6-O-α-L-rhamnosyl)glucoside (1) as a major flavonol glycoside in the extract. A robust and validated HPLC method was established for quantification of this compound (0.33 mg/g in the 60% ethanol extract of the leaves), supporting the standardization of the extract. These findings suggest that O. humifusa leaf extract, particularly the 60% ethanol extract, may serve as a promising natural prebiotic ingredient for use in functional foods or synbiotic formulations. Full article

The color of flowers in Osmanthus fragrans is regulated by carotenoid metabolism. The orange-red variety, Dangui, is believed to have evolved from the yellow variety, Jingui, through a natural bud mutation. This study uses the Jingui cultivar ‘Jinqiu Gui’ (JQG) and its bud mutation cultivar ‘Huolian Jindan’ (HLJD) as materials, combining genome resequencing, ultrastructural observation, targeted metabolomics, and transcriptomic analysis to elucidate the molecular and cellular mechanisms underlying flower color variation. Phylogenetic analysis confirms that HLJD is a natural bud mutation of JQG. Ultrastructural observations reveal that during petal development, chromoplasts are transformed from proplastids. In HLJD petals, starch granules degrade more slowly and exhibit abnormal morphology, resulting in chromoplasts displaying crystalline, tubular, and fibrous composite structures, in contrast to the typical spherical plastoglobuli found in JQG. Targeted metabolomics identified 34 carotenoids, showing significant increases in the levels of ε-carotene, γ-carotene, α-carotene, and β-carotene in HLJD petals compared to JQG, with these levels continuing to accumulate throughout the flowering process, while the levels of the cleavage products α-ionone and β-ionone decrease. Transcriptomic analysis indicates that carotenoid metabolic pathway genes do not correlate directly with the phenotype; however, 49 candidate genes significantly associated with pigment accumulation were identified. Among these, the expression of genes such as glycoside hydrolases (LYG036752, etc.), sucrose synthase (LYG010191), and glucose-1-phosphate adenylyltransferase (LYG003610) are downregulated in HLJD. This study proposes for the first time the pathway of “starch degradation delay → chromoplast structural abnormalities → carotenoid cleavage inhibition” for deepening flower color, providing a new theoretical model for the metabolic regulation of carotenoids in non-photosynthetic tissues of plants. This research not only identifies key target genes (such as glycoside hydrolases) for the color breeding of O. fragrans but also establishes a theoretical foundation for the color enhancement of other ornamental plants. Full article

This study investigates how root color in soybeans affects isoflavone composition, rhizosphere bacterial diversity, total phenolics, total flavonoids, and antioxidant activity under a hydroponic cultivation system. Notably, soybean-brown roots (SBRs) accumulated significantly higher contents of isoflavones, exhibiting approximately a 14.9-fold increase in total glycosides (141.75 to 2121.59 µg/g), 7.3-fold increase in total malonyl-β-glycosides (127.52 to 930.45 µg/g), 2.8-fold increase in total aglycones (1825.90 to 5145.21 µg/g), and 3.9-fold increase in total isoflavones (2095.16 to 8197.26 µg/g) than soybean-white roots (SWRs). Isolated rhizosphere bacteria profiling revealed γ-Proteobacteria as the predominant class in both root types, constituting 77.6% and 73.9% of the bacterial community in SWRs and SBRs, respectively. However, SBRs supported a more diverse bacterial ecosystem, harboring thirteen genera compared to only eight genera in SWRs. Enhanced total phenolics, total flavonoids, and radical scavenging activity were also associated with the SBRs. These findings shed light on the dynamic interplay between root traits, bacterial interactions, and secondary metabolite biosynthesis in hydroponically grown soybeans. This work not only advances our understanding of plant root–microbiome–metabolite relationships but also offers a novel approach to exploring the potential of enhancing secondary metabolites in soybean plants through precision cultivation. Full article

SGLT2 inhibitors have become increasingly used due to their effectiveness in improving not only type 2 diabetes but also cardiovascular, renal and hepatic diseases, as well as the obesity found in metabolic syndrome. Starting from the structure of gliflozins, modifications of the carbohydrate part, aglycone, and also the glycosidic bond between them can determine variations in pharmacokinetic and pharmacodynamic properties. SGLT2 inhibitors, in addition to reducing blood glucose levels, improve alterations in lipid metabolism by diverting excessively accumulated lipids in tissues towards mobilization, lipolysis, β-oxidation, ketogenesis and the utilization of ketone bodies. This enhances anti-inflammatory properties by decreasing the levels of some proinflammatory mediators and by modulating some cell signaling pathways. Thus, in this review, the intimate mechanisms by which SGLT2 inhibitors achieve these therapeutic effects in the various conditions belonging to metabolic syndrome and beyond were described, along with the structure–effect relationship with some specific features of each gliflozin. Starting from these findings, further modeling of these molecules may lead to the creation of new therapeutic uses. Further research is needed to broaden the range of indications and also eliminate adverse effects, such as phenomena leading to lower limb amputations. Full article

Glycoside hydrolase family 1 (GH1) enzymes are essential for plant cell wall digestion and the detoxification of plant metabolites in insects, yet their evolutionary history in Lepidoptera remains unresolved. This study systematically identified GH1 genes across 61 Lepidopteran genomes and analyzed their evolutionary dynamics. In addition, the expression profiles of GH1 genes in the silkworm (Bombyx mori) across various developmental stages and tissues were related to their evolutionary histories. A total of 996 GH1 genes were annotated and classified into 11 groups, with each showing distinct species diversity. Gene duplication and loss analysis revealed frequent duplications and losses during Lepidoptera evolution; these duplications primarily originated through tandem and dispersed duplications and were located in syntenic regions. Transcriptomic analysis of the silkworm revealed that the groups and duplications of GH1 genes were correlated to their expression patterns, with high expression in the larval midgut and fat body. These findings suggest that GH1 gene duplications and losses and expression have played a significant role in Lepidopteran adaptation to diverse host plants. Overall, this study provides comprehensive insights into the evolutionary trajectories of GH1 genes, highlighting their potential contribution to insect–plant interactions in Lepidoptera. Full article

Ganoderma lucidum polysaccharides (GLPs) are natural compounds with a broad spectrum of biological activities. β-1,3-glucosyltransferase (GL20535) plays an important role in polysaccharide synthesis by catalyzing the transfer of UDP-glucose to extend sugar chains, but its underlying mechanism remains unclear. In this study, the regulatory mechanism of GL20535 in polysaccharide synthesis was elucidated by overexpressing and silencing gl20535 in G. lucidum. Overexpression of gl20535 resulted in maximum increases of 18.08%, 79.04%, and 18.01% in intracellular polysaccharide (IPS), extracellular polysaccharide (EPS), and β-1,3-glucan contents, respectively. In contrast, silencing gl20535 resulted in maximum reductions of 16.97%, 30.20%, and 23.56% in IPS, EPS, and β-1,3-glucan contents, respectively. These phenomena in the overexpression strains were attributed to gl20535-mediated promotion of UDP-glucose synthesis in the sugar donor pathway and upregulation of the expression of glycoside hydrolase genes. The opposite trend was observed in the silenced strains. In mycelial growth studies, neither overexpression nor silencing of gl20535 affected biomass and cell wall thickness. Furthermore, the GL20535 isozyme gene gl24465 remained unaffected in gl20535-overexpressed strains but was upregulated in gl20535-silenced strains, suggesting a compensatory regulatory relationship. These findings reveal the regulatory role of GL20535 on gene expression in the GLPs synthesis pathway and deepen our understanding of GL20535 function in the polysaccharide network of edible and medicinal fungi. Full article

Thermostable cellulases and xylanases have broad acceptance in food, feed, paper and pulp, and bioconversion of lignocellulosics. Thermophilic fungi serve as an excellent source of thermostable enzymes. This study characterized four endo-β-1,4-glucanases (two glycoside hydrolase (GH) family 5 and two GH7 members) and four endo-β-1,4-xylanases (two GH10 and two GH11 members) from thermophilic fungus Thielavia terrestris, along with one GH10 endo-β-1,4-xylanase each from thermophilic fungus Chaetomium thermophilum and mesophilic fungus Chaetomium globosum. Comparative analysis was conducted against three previously reported GH10 endoxylanases: two thermostable enzymes from the thermophilic fungus Humicola insolens and thermophilic bacterium Halalkalibacterium halodurans, and one mesophilic enzyme from model fungus Neurospora crassa. The GH10 xylanase TtXyn10C (Thite_2118148; UniProt G2R8T7) from T. terrestris demonstrated high thermostability and activity, with an optimal temperature of 80–85 °C. It retained over 60% of its activity after 2 h at 70 °C, maintained approximately 30% activity after 15 min at 80 °C, and showed nearly complete stability following 1 min of exposure to 95 °C. TtXyn10C exhibited specific activity toward beechwood xylan (1130 ± 15 U/mg) that exceeded xylanases from H. insolens and H. halodurans while being comparable to N. crassa xylanase activity. Furthermore, TtXyn10C maintained stability across a pH range of 3–9 and resisted trypsin digestion, indicating its broad applicability. The study expands understanding of enzymes from thermophilic fungi. The discovery of the TtXyn10C offers a new model for investigating the high activity-stability trade-off and structure-activity relationships critical for industrial enzymes. Full article

Celtis iguanaea, widely used in Brazilian folk medicine, is known for its analgesic and anti-inflammatory properties. This study evaluated the in vitro antioxidant capacity and the in vivo antinociceptive and anti-inflammatory mechanisms of the standardized spray-dried Celtis iguanaea hydroethanolic leaf extract (SDCi). Phytochemical analysis showed that SDCi contains 21.78 ± 0.82 mg/g polyphenols, 49.69 ± 0.57 mg/g flavonoids, and 518.81 ± 18.02 mg/g phytosterols. UFLC-DAD-MS identified iridoid glycosides, p-coumaric acid glycosides, flavones, and unsaturated fatty acids. Antioxidant assays revealed an IC₅₀ of 301.6 ± 38.8 µg/mL for DPPH scavenging and an electrochemical index of 6.1 μA/V. In vivo, SDCi (100–1000 mg/kg, p.o) did not impair locomotor function (rotarod test) but significantly reduced acetic acid-induced abdominal writhing and both phases of the formalin test at higher doses (300 and 1000 mg/kg). The antinociceptive effects were independent of α-2 adrenergic receptors. SDCi also increased latency in the hot-plate test and reduced paw edema in the carrageenan model, accompanied by decreased IL-1β and increased IL-10 levels. Histological analysis showed a 50% reduction in inflammatory cell infiltration. These findings support SDCi as an effective anti-inflammatory and antinociceptive phytopharmaceutical intermediate, with potential applications in managing pain and inflammation. Full article

This study investigated the correlation between five primary volatile phenols (VPs) and their glycosides in smoke-exposed and non-smoke-exposed Pinot noir wines to assess and identify potential markers for smoke taint. The results showed that all putative VP-glycosides in smoke-exposed wines were higher than in non-smoke-exposed wines, with a fold change ranging from 2.11 to 31.88 for the top fifteen differentiations. VP-glycosides showed strong positive correlations among themselves, with correlation coefficients of 0.94 for hexose-guaiacol vs. pentose (P)-hexose (H)-cresol and 0.92 for syringyl-β-D-glucopyranoside vs. H-P-4-methylguaiacol. VP-glycosides also showed relatively high correlations with free and strong acid-hydrolyzed VPs. The correlation coefficient between H-P-guaiacol and free-form guaiacol is 0.71, and between H-P-guaiacol and total guaiacol is 0.78. The strong correlation suggests that these compounds are interconnected and regulated by the severity of smoke exposure. Multivariate analysis effectively differentiated smoke-exposed wines from non-smoke-exposed ones. However, more research is needed to fill the gaps in understanding smoke-derived compounds. Full article

Cancer remains a leading global health challenge, necessitating the exploration of novel therapeutic strategies. Vitexin (apigenin-8-C-β-D-glucopyranoside), a natural flavonoid glycoside with a molecular weight of 432.38 g/mol, is derived from plants such as mung bean, beetroot, and hawthorn. This compound features a distinctive C-glycosidic bond at the 8-position of its apigenin backbone, contributing to its enhanced metabolic stability compared to O-glycosidic flavonoids. Preclinical studies demonstrate that vitexin modulates critical cellular processes such as cell cycle progression, apoptosis, autophagy, metastasis, angiogenesis, epigenetic modifications, and tumor glycolysis inhibition. It exerts its effects by targeting key signaling pathways, including phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and signal transducer and activator of transcription 3 (STAT3), and shows potential for combination therapies to enhance efficacy and overcome resistance. Advances in nanotechnology further enhance its bioavailability and delivery potential. This review comprehensively examines the current evidence on vitexin’s anticancer mechanisms, highlighting its multi-target therapeutic potential and future research directions. Full article

In this study, three new 3,7-dihydroxyflavone (1) derivatives with different sugars were designed and synthesised by click chemistry. Click chemistry requires the previously modification of building blocks with azide and alkyne groups and therefore, the 3,7-dihydroxyflavone (1) was first converted in 3,7-(prop-2-yn-yloxy)flavone (2) and acetobromo-α-D-glucose (3) was converted into 2,3,4,6-tetra-O-acetyl-β-glucopyranosyl azide (4). Subsequently, a click reaction was performed via copper-catalysed cycloaddition (CuAAC) between 2 and 4, as well as between 2 and 2-acetamido-3,4,6-tetra-O-acetyl-2-deoxy-β-D-glucopyranosyl (AG931) and, 2 and commercial 2-azidoethyl 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl (AG358), resulting in three distinct disubstituted flavone glycosides (5a–5c). Biological assays performed on L929 fibroblast cell lines and human glioblastoma astrocytoma U-251 cell lines indicated cytocompatibility with fibroblasts and reduced metabolic activity of GBM cells in the presence of compound 5b and 5c. To enhance therapeutic effect, improve local drug delivery, and overcome solubility issues of these high molecular weight compounds, the synthesised compounds were encapsulated in polymeric particles (polymersomes, PMs) composed of polylactic acid-polyethylene glycol (PEG-PLA) functionalized, once more by click chemistry, with 0.1 mol% transferrin mimetic (T7—HRPYIAH) peptide. The PMs were prepared by solvent displacement and exhibited stability over 100 days, encapsulation efficiency of 39–93%, and mean size diameters of 120–180 nm. The toxicity assays of the PMs on the U-251 cell line showed a significant decrease in metabolic activity, supporting the potential of this delivery system against GBM. Among the PMs tested, the flavone 5c-based PM demonstrated the highest efficacy. Full article

Immunotherapy is a transformative strategy in oncology, yet the development of novel immunomodulatory agents remains essential. This study explores the anti-tumor potential of a structurally unique polysaccharide isolated from an Aspergillus ochraceus (AOP), sourced from the Antarctic Weddell Sea. Using alkaline-assisted extraction and chromatographic purification, we obtained a homogeneous polysaccharide predominantly composed of galactose and mannose, with an average molecular weight of 39.67 kDa. The structure was characterized by an integrated nuclear magnetic resonance spectroscopy and mass spectrometry analysis, revealing that the AOP is composed of β (1→5)-linked galactofuranose units, with a minor substitution by α-D-mannopyranose residues via (1→2) glycosidic bonds at the C2 of the galactofuranose. Functional assays, including CCK8 and wound-healing tests, demonstrated that this polysaccharide, referred to as AOP, inhibited melanoma cell proliferation and migration in a dose-dependent manner. Additionally, the AOP activated RAW264.7 and bone marrow-derived macrophage (BMDM) cells without exhibiting significant cytotoxicity, leading to the release of inflammatory factors such as TNF-α, IL-1β, and IL-6. Mechanistically, the AOP was found to upregulate the expression of CD86 and IFN-γ, while downregulating genes like IL-4 and Arg1. These findings position the AOP as the first documented Antarctic fungal polysaccharide with macrophage-reprogramming capabilities against melanoma, offering novel molecular insights for marine-derived immunotherapeutics. Full article