Search Results (2,536)

In this study, the native activity of an arabinogalactan endo-β-1,4-galactanase from Aspergillus niger (AnGal) was evaluated under different reaction conditions, and in the presence of various acceptor molecules during the cleavage of the β-1,4-glycosidic linkage of a chromogenic compound and lupin galactan. A combination of spectrophotometric assays, mass spectrometry and chromatography techniques provided insights into the reaction mechanism of the enzyme and its use in the synthesis of galactosides and galactooligosaccharide derivatives. In reactions containing 2-nitrophenol galactopyranoside, AnGal promoted transglycosylation, generating longer galactooligosaccharide derivatives of 2-nitrophenol that have not previously been reported for GH53 enzymes. Furthermore, new alcoholysis products have been detected when AnGal acted on lupin galactan in the presence of benzyl alcohol. To the best of our knowledge, we are first to report the synthesis of galactotriose and galactotetraose derivatives formed by endo-β-1,4-galactanase alcoholysis. This work showcases the potential of utilizing galactanases in the synthesis of valuable galactosides and galactooligosaccharides, under mild conditions from sustainable biomass sources. Potential beneficial applications may be found in several industrial fields such as in the preparation of prodrugs and prebiotics. Full article

Background/Objectives: Methylglyoxal (MGO) and subsequent activation of advanced glycation end products (AGEs)–RAGE receptor signaling has been implicated in the complications of diabetes mellitus (DM), such as bladder dysfunction. Chronic treatment with MGO leads to bladder overactivity, but the effects of acute MGO exposure have not yet been evaluated. Methods: In this study, we used female wild-type, endothelial nitric oxide (eNOS) knockout (eNOS^−/−), and triple (neuronal/endothelial/inducible) NOS^−/− mice to investigate the effects of incubation of MGO (10 to 300 µM) on bladder contractions induced by carbachol and electrical field stimulation (EFS). We also analyzed the activity of the MGO detoxification enzyme glyoxalase 1 (Glo1). Results: Incubation with MGO at 10 and 30 µM in urothelium-intact preparations produced marked detrusor hypercontractility to both carbachol and EFS that was abolished by urothelium removal. Detrusor hypercontractility was associated with the generation of reactive oxygen species (ROS), RAGE activation, Rho kinase sensitization, and activation of TRPA1 and TRPV4 channels. At higher concentrations (100 and 300 µM), MGO did not significantly affect the detrusor contractility to carbachol and EFS, but L-NAME pretreatment restored the hypercontractile state by MGO. Likewise, in bladder strips obtained from eNOS^−/− or triple NOS^−/− mice, MGO exposure (300 µM) significantly enhanced carbachol and EFS-induced contractions, indicating a major role for nitric oxide (NO) counteracting the hypercontractility. No concentration of MGO altered Glo1 activity in bladder tissues. Conclusions: In conclusion, progressive MGO accumulation may account for the transition from the initial hyperactive phase to the subsequent hypoactive decompensated phase of diabetic bladder dysfunction. Full article

Atalantia ceylanica, locally known as Yaki naran (YK), is a native plant of Sri Lanka, growing commonly in the dry and wet–intermediate zones. In this study, powdered samples of Yaki naran (YK) were sequentially extracted using hexane, ethyl acetate (EtOAc), and methanol (MeOH). The resulting extracts were assessed for total phenolic content, antioxidant potentials, and in vitro α-amylase, α-glucosidase, and lipase inhibitory activities using relevant assays. The crude extracts were then subjected to separation and purification by column chromatography and preparative thin-layer chromatography. Although twelve compounds were obtained from the three crude extracts, only three had sufficient yields to proceed. Out of the three pure isolates, compound SAC 4 was identified as 2,4-di-tert-butylphenol, a phenolic compound, by using ¹H and ¹³C NMR data and FTIR spectroscopic data, followed by evaluation of bioactivities such as antioxidant properties, enzyme inhibitory assays, etc. Based on the results of the bioassays, compound SAC 4 was identified to show strong α-glucosidase inhibitory activity, moderate antioxidant activity, and lipase inhibitory activity. Full article

Starch–polyphenol complexes have attracted increasing attention as functional ingredients for improving the structural stability and reducing the glycemic potential of starch-based foods, yet their application in extruded fresh noodles remains insufficiently understood. In this study, chestnut starch–resveratrol complexes prepared by heat-moisture synergistic recrystallization treatment (CS-HMRT-Res) were incorporated into extruded fresh noodles, and their quality, structural characteristics, digestibility, and glycemic response were systematically evaluated. Compared with commercial wheat-based Regan noodles, CS-HMRT-Res noodles exhibited enhanced cooking stability (lower swelling and leaching) and improved texture (hardness, chewiness, tensile strength), with a markedly lower total color difference after cooking (ΔE = 1.8 vs. 6.5). SEM, FTIR and XRD indicated a more compact and ordered network; the relative crystallinity of cooked noodles increased to approximately 30.8%. In in vitro digestion, CS-HMRT-Res showed the lowest starch hydrolysis extent at 180 min (45.92%) and yielded a low predicted glycemic index of 53.35, compared with 70.65 for Regan noodles. Consistently, gavage studies in mice confirmed that HMRT-Res-chestnut starch produced the lowest postprandial blood glucose increment response (4.31 mmol/L). Molecular dynamics simulations further suggested that resveratrol could competitively occupy the α-amylase binding cavity and reduce starch accessibility to the enzyme. Overall, CS-HMRT-Res improved processing quality, structural integrity, and reduced glycemic potential, offering a structure-function framework for designing low-GI products. Full article

Organophosphate pesticides are widely used agricultural chemicals that pose significant environmental and health risks due to their neurotoxicity, which is associated with inhibition of acetylcholinesterase. In this study, carbon materials derived from rabbit litter-based precursors were investigated as sustainable adsorbents for the removal of organophosphate pesticides from aqueous systems. The prepared materials exhibited a broad range of textural properties, with specific surface areas ranging from 10 to 487 m² g⁻¹, depending on the precursor composition. Adsorption experiments demonstrated measurable removal of chlorpyrifos, malathion, and dimethoate, with maximum adsorption capacities reaching 71.8 mg g⁻¹ for malathion, although adsorption performance varied among materials, indicating a combined influence of pore accessibility and surface chemical heterogeneity. Evaluation of acetylcholinesterase inhibition before and after adsorption showed a consistent decrease in enzyme inhibition across all systems, with values reduced from 40% to as low as 20% for chlorpyrifos, from 35% to as low as 11% for malathion, and from 20% to as low as 10% for dimethoate, indicating a reduction in the neurotoxic potential of the treated solutions. In addition, the genotoxicity of the carbon materials varied with their structural and compositional characteristics, underscoring the importance of considering both adsorption performance and biological interactions. These findings demonstrate that waste-derived carbon materials can contribute to the removal of organophosphate contaminants while simultaneously reducing their associated neurotoxic effects. Full article

Deposit-feeding sea cucumbers ingest sediment-like particles, making substrate-associated exposure pathways ecologically relevant in coastal aquaculture. In this study, a sea mud feed matrix was used to evaluate short-term dietborne/substrate-linked glyphosate exposure in Apostichopus japonicus over 72 h, with the aim of characterizing early residue formation, short-term sublethal biomarker responses, and gut microbiota shifts under a benthic feeding scenario. Analytical verification confirmed a clear glyphosate gradient in the prepared feed matrices, with no glyphosate detected in the control matrix and measured concentrations of 8.66 ± 1.59 mg/kg, 1330 ± 390 mg/kg, and 6960 ± 1710 mg/kg in the low-, medium-, and high-dose groups, respectively. No mortality or obvious external lesions were observed during the exposure period. Tissue analysis confirmed measurable internal glyphosate residues and compartment-specific distribution, indicating successful internal exposure under the matrix-linked route. Most digestive and immune/antioxidant biomarkers remained relatively stable within the 72 h window; however, amylase showed a marked response in the low-dose group, and superoxide dismutase showed dose-associated changes in the medium- and high-dose groups, indicating selective sensitivity among enzyme endpoints. Gut microbiota analysis revealed a dominance-structured community with limited alpha-diversity variation among groups, whereas community composition showed subtle treatment-related shifts that were more evident at finer taxonomic resolution. Predicted functional profiles remained broadly similar across treatments. Overall, the 72 h exposure design was effective for identifying early internal exposure and short-term biological responses under a sea mud-associated feeding route, while host physiological responses remained largely buffered over this time scale and the gut microbiota provided a more sensitive interface-level signal of exposure-associated change. These findings support the value of a route-specific, gut-centered framework for evaluating early herbicide exposure responses in benthic mariculture species and suggest that matrix-associated feeding conditions may modify the apparent magnitude of short-term responses. Full article

Chloramphenicol is a broad-spectrum antimicrobial agent whose use in food-producing animals is prohibited in many countries due to its association with severe adverse effects, including idiosyncratic aplastic anemia and genotoxicity. Despite these restrictions, chloramphenicol residues continue to be detected in food products, environmental compartments, and biological matrices, highlighting the need for reliable and sensitive analytical monitoring. This review provides a comprehensive overview of current analytical strategies for the detection of drugs in food and environmental samples, covering screening and confirmatory techniques, sample preparation approaches, and regulatory aspects. Rapid screening methods, such as enzyme-linked immunosorbent assays (ELISAs), lateral flow immunoassays (LFIAs), and biosensors based on antibodies, aptamers, and molecularly imprinted polymers, enable fast and cost-effective preliminary detection. Recent advances in nanomaterials and signal amplification strategies, including fluorescent reporters and surface-enhanced Raman scattering (SERS), have significantly improved sensitivity and assay performance. However, confirmatory methods based on liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) remain the reference standard due to their superior selectivity, sensitivity, and quantitative reliability. Attention is given to sample preparation workflows, including QuEChERS-based protocols and microextraction techniques, which enable efficient analysis of complex matrices. Finally, current regulatory frameworks and analytical challenges related to zero-tolerance policies are discussed, emphasizing the importance of robust and validated analytical methods for effective monitoring and food safety assurance. Full article

Selective inhibition of the tumour-associated carbonic anhydrase (CA) isoforms IX and XII, which are overexpressed in hypoxic tumours, has emerged as a promising strategy for the development of novel anticancer agents. Among the diverse CA inhibitors reported to date, coumarins have attracted particular attention. These chromenone derivatives, widely distributed in phytochemicals, display a broad range of biological activities and are known to act as suicide inhibitors of CAs. Following the tail approach, we designed a series of hybrid compounds combining a coumarin core with an N-arylthioureido scaffold located at the C-7 position and investigated how structural variations—including substituents on the coumarin and aromatic moieties, tether length, and urea/thiourea isosterism—influence their biological properties (CA inhibition and antiproliferative activity). Substituted coumarins at C-3 and C-4 were efficiently prepared via Pechmann condensation, while the thioureido motif was introduced using various aryl isothiocyanates as key synthetic intermediates. The lead compound, featuring a dimethylated coumarin, a pentyl linker, and an N-(p-tolyl)thioureido residue, inhibited the target enzymes in the low- to mid-nanomolar range (K_i = 6.0 and 49.9 nM, respectively), displaying selectivity indexes (S.I.s) surpassing those of the reference drug acetazolamide (AAZ). Moreover, it exhibited potent antiproliferative activity, with GI₅₀ values in the low micromolar range (1.9–3.5 µM) against both drug-sensitive and multidrug-resistant cancer cell lines. Label-free three-dimensional holotomographic microscopy revealed that this compound triggers slow apoptosis, leading to cell death after approximately 20 h of exposure. Full article

The enzymatic saccharification of cellulose remains a key step in biomass conversion processes, often influenced by enzyme stability, distribution, and accessibility at solid–liquid interfaces. Immobilization of cellulolytic enzymes on nanostructured supports has been proposed as a strategy to modulate catalytic behavior; however, the relationship between enzyme loading and catalytic response remains insufficiently understood. In this study, CuO-based nanobiocatalysts were prepared through controlled cellulase immobilization and systematically evaluated under defined experimental conditions. Structural and physicochemical characterization was performed using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and integrated thermal analysis (TGA–DTG–DSC), enabling a comparative assessment of the analyzed systems. SEM analysis showed that the average particle diameter increased from 39.5 ± 14.8 nm (CuO nanoparticles) to 95.6 ± 21.8 nm (NPI10), 106.6 ± 27.7 nm (NPI15), and 113.5 ± 23.1 nm (NPI20), indicating progressive variations in particle organization with increasing enzyme loading. Catalytic performance was evaluated through enzymatic hydrolysis of cellulose filter paper as a model substrate, with products quantified by HPLC at a representative reaction time. The system prepared at lower enzyme loading (NPI10) exhibited product formation comparable to that of the free enzyme, with apparent average glucose formation values of 1.054 and 1.047 mg·mL⁻¹·h⁻¹, respectively. In contrast, higher immobilization levels were associated with reduced catalytic output. Across all systems, glucose was the predominant product, with negligible accumulation of intermediate oligomers under the evaluated conditions. These results indicate that increasing enzyme loading does not correspond to proportional increases in product formation and highlight the influence of enzyme distribution and accessibility within the system. The combined structural and catalytic observations provide a controlled framework for evaluating how immobilization conditions influence system behavior in nanobiocatalytic systems. Full article

Photoaging is an extrinsic skin aging process caused by chronic ultraviolet (UV) radiation. A core pathological feature of photoaging is excessive oxidative stress, which can further induce ferroptosis. The HSP70 family plays a critical role in this stress response by protecting the key antioxidant enzyme GPX4. In this study, we established UV-induced photoaging models in cultured cells and 3D skin organoids. UPLC-MS/MS analysis of Chenpi transdermal permeate (prepared by in vitro transdermal penetration of Chenpi extract through mouse skin) identified hesperidin as the primary bioactive compound of Chenpi (dried peel of the plant Citrus reticulata Blanco after the aging process). The efficacy of hesperidin was validated in human keratinocytes (HaCaTs), fibroblasts (HSFs), and skin organoids. Mechanistically, transcriptomic and metabolomics analysis indicated that ferroptosis is a key pathway through which hesperidin ameliorates photoaging. Limited proteolysis mass spectrometry (LiP-MS), transcriptomics, and molecular dynamics simulation results demonstrated that hesperidin directly binds to the molecular chaperone HSPA1L. By upregulating HSPA1L expression, hesperidin enhanced the stability of GPX4 and suppressed UV-triggered ferroptosis. Our findings identify the HSPA1L/GPX4 axis as a critical redox regulatory pathway targeted by hesperidin, providing a mechanistic foundation for anti-photoaging therapies. Full article

Blood glutathione (GSH), its oxidized form glutathione disulfide (GSSG), and especially the ratio of reduced to oxidized glutathione (GSH/GSSG) are recognized as robust biomarkers of oxidative stress. However, the broader application of these biomarkers has been limited by two major challenges: (1) the high risk of artifact formation during sample handling, which can artificially increase GSSG levels and bias redox balance measurements, and (2) the reliance on complex, instrument-intensive analytical procedures and the requirement for venous blood. We present an adaptation of the highly sensitive and easy-to-perform Tietze recycling method for microvolumes of blood. The challenge is to achieve accurate and precise measurements while avoiding artifacts, taking advantage of the high sensitivity of this enzymatic recycling analytical procedure. The method uses a simplified sample preparation protocol compatible with small blood volumes (up to 10 μL) and requires only basic laboratory equipment, such as a standard spectrophotometer or microplate reader. As this is an enzyme-based assay, we also carefully evaluate the main factors that can affect the measurements. This novel procedure provides a practical tool for monitoring GSH/GSSG as a biomarker of oxidative stress in various experimental settings by eliminating the need for trained personnel for blood sampling (it is suitable for capillary blood), minimizing discomfort for subjects, and avoiding complex procedures or instruments for analyte detection. Full article

This study investigates the extraction of pectic polysaccharides from rapeseed meal (RSM) using both conventional and enzyme-assisted techniques, and the obtained pectic polysaccharide fractions will be used later to produce prebiotic pectic oligosaccharides (POS). A two-step process was developed, involving enzymatic treatment with Alcalase^® 2.4 L for 2 h and Cellic^® CTec3 HS preparations for 24 h, followed by ammonium oxalate extraction, which effectively isolated two pectic polysaccharide-enriched fractions: PP-EAE (first step) and the resulting Ca-bound pectic polysaccharides fraction (CaPP-EAE) (second step). Both fractions exhibited a bimodal molecular weight profile, indicative of the presence of long-chain polysaccharides alongside oligosaccharides. CaPP-EAE compositional analysis revealed that the fraction contained 56.8% galacturonic acid (GalA), low methyl-esterified (LM) pectins with 53.2% homogalacturonan (HG) and 30.2% rhamnogalacturonan I (RG-I) domains, featuring side chains of arabinan, arabinogalactan, and galactan. Subsequent enzymatic treatment with 0.5% (v/v) of Pectinex^® Ultra Passover for 30 min transformed these fragments into a mixture of short-chain POS. Importantly, the produced short-chain POS fraction demonstrated enhanced prebiotic activity, particularly for bacterial strains of the family Lactobacillaceae, compared to a yeast strain. These findings provide a sustainable, biorefinery-compatible approach for extracting and modifying RSM polysaccharides, supporting the development of structurally defined POS as novel prebiotics. Full article

Saponins, the primary bioactive constituents with immunomodulatory activities in Baoyuan decoction—a traditional Chinese medicine formula composed of ginseng, astragalus, licorice, and cinnamon—are limited by low extraction yield, poor stability, and easy degradation. In this study, cellulase and pectinase were used for the extraction of saponins from Baoyuan decoction and optimized by response surface methodology. Subsequently, the optimal extracts were microencapsulated by spray drying with soy protein isolate (SPI) or high-oleic acid soy protein isolate (HOSPI) and pectin (PE) as composite wall materials, followed by application evaluation in gummies and in vitro digestion. After optimization, the total saponin yield was 63.68 ± 0.15 mg/g. HOSPI-PE microcapsules (HBP) had a higher encapsulation efficiency (90.38%), smaller particle size, and lower hygroscopicity than SPI-PE ones (SBP). Furthermore, both microcapsules showed good stability during storage and controlled release, with 60.9% of saponins in SBP and 65.8% in HBP being delivered to the intestinal phase during in vitro digestion of microparticles. When applied in gummies, microcapsule gummies retained satisfactory sustained-release in vitro digestion (23.0% released in the stomach and 66.2% in the small intestine). In contrast, the unencapsulated gummies exhibited a burst release (74.4%) at 30 min in gastric digestion. This study provides theoretical and technical insights into the development of plant-derived functional foods and promotes the practical application of microencapsulation in functional gummy candies. Full article

Medlar (Mespilus germanica L.) fruit presents a good source of bioactive compounds. This study aimed to optimize the traditional extraction method, maceration, in order to obtain extracts rich in polyphenols. The total phenolic compounds (TPC) from physiologically ripe (PRMFs) and consumable ripe (CRMFs) medlar fruits were extracted to develop models with high accuracy and prediction capacity by response surface methodology (RSM). Furthermore, the main phenolic compounds in the extracts were quantified using HPLC, and the extracts were tested for antioxidant activity and hypoglycemic activity. The extracts were prepared according to a central composite design. The extraction parameters for both PRMFs and CRMFs were time (30–210 min), ethanol concentration (20–80%) and solid-to-solvent ratio (1:10–1:50). The obtained results indicated that the optimal conditions for the extraction were 210 min, 66.55% ethanol, and 1:50 solid-to-solvent ratio (PRMF), and 120 min, 74.96% ethanol, and 1:50 solid-to-solvent ratio (CRMF). Under the optimized conditions, values for TPC were in agreement with the values predicted by RSM. Isoquercitrin, rutin, procyanidin B2, chlorogenic acid and caffeic acid were the most abundant compounds in both PRMF and CRMF optimized extracts. TPC, antioxidant activity, and inhibition of α-glucosidase and α-amylase enzymes did not show significant differences (p > 0.05) among PRMF and CRMF extracts. Full article

Proteases are key biocatalysts widely applied in the food, pharmaceutical, detergent, and environmental industries. One of the most costly steps in large-scale enzyme production is the preparation of the culture medium, making agro-industrial wastes attractive as low-cost nutrient sources and potential inducers. The non-conventional yeast Yarrowia lipolytica stands out in bioprocess engineering due to its high secretion capacity, GRAS status, and ability to metabolize diverse industrial residues. In this study, Brazilian agro-industrial by-products, namely Corn steep liquor (CSL), brewer’s yeast residue (BYR), and okara, were evaluated as alternative nitrogen sources for protease production by Y. lipolytica IMUFRJ 50678. Enzyme activity was quantified by the azocasein method at optimized conditions (40 °C, 40 min, pH 5 and 8). After an initial exploratory screening (n = 1), brewer’s yeast residue (BYR) and okara were identified as promising candidates for protease production. These preliminary findings guided subsequent experiments performed in biological triplicate (n = 3), which confirmed the reproducibility and comparative performance of these substrates, showing higher acid protease (AXP) activity in the BYR medium ((5.4 ± 0.3) U/mL), whereas alkaline protease (AEP) activities were comparable between the BYR ((8.4 ± 0.6) U/mL) and okara ((7.5 ± 0.9) U/mL) media. CSL was associated with higher lipase activity ((11.7 ± 0.9) × 10³ U/L), while esterase activity was higher in the BYR medium. These findings indicate that agro-industrial residues, particularly BYR and okara, can serve as effective nitrogen sources for protease production by Y. lipolytica IMUFRJ 50678, supporting their use in waste valorization and sustainable bioprocesses. Full article