Search Results (54,507)

Medicarpin, a natural pterocarpan phytoalexin, contributes to tree defense against microbial decay, particularly from the aggressive white-rot fungus Trametes versicolor, an ASTM standard for wood durability testing. To improve upon the inhibitory effect of medicarpin against this fungus (150 mg/L), eleven derivatives were synthesized and evaluated. The acetylated analog demonstrated superior activity, achieving complete growth inhibition at 100 mg/L. To establish a structure–activity relationship, molecular docking was performed on the copper cluster on fungal laccase, the primary oxidative enzyme of T. versicolor. The acetylated derivative bound the T1 copper site with a more favorable free energy (−8.5 kcal/mol) than the parent compound, exhibiting enhanced stabilizing interactions and a binding pose anchored closer to the trinuclear copper cluster (TNC). These results were corroborated by 80 ns molecular dynamics simulations, confirming complex stability and the persistence of key interactions. This study demonstrates that targeted chemical modification of natural phytoalexins can significantly improve their antifungal potency. The superior performance of the acetylated medicarpin derivative, linked to optimized binding at the laccase active site, establishes a clear structure–activity relationship and highlights the potential of such engineered compounds as leads for next-generation, bio-inspired wood preservatives. Full article

The global prevalence of obesity continues to rise, posing serious risks to human health largely because obesity itself leads to metabolic disorders of carbohydrate and lipids. Currently, effective and healthy interventions for lowering blood glucose, reducing blood lipids, and promoting weight loss remain limited due to the complexity of obesity development. Lactobacillus plantarum (GDMCC 1.140) was shown to promote catabolic processes and reduce hepatic lipid accumulation in largemouth bass fed with high-starch feed (HSF) in our previous study; however, molecular mechanisms underlying the function of this probiotic remain unclear. Here, we evaluated the effects of L-carnosine, one of metabolites produced by Lactobacillus plantarum, on carbohydrate and lipid metabolisms in an obesity model of zebrafish, which was induced by HSF. Histopathological analyses of livers from different groups indicated that a dietary supplement with L-carnosine can alleviate hepatic impairment and reduce lipid accumulation in the hepatocytes of obese zebrafish. Transcriptomic analyses revealed that L-carnosine supplementation can reverse the expression of about 70 HSF-induced genes, mainly gene-specific transcription regulators and metabolite interconversion enzymes. Furthermore, approximately 250 HSF-inhibited genes were found to be up-regulated by L-carnosine, reaching levels comparable to those in normal-starch feed (NSF) zebrafish. These genes, targeted by L-carnosine and inhibited by HSF, are highly enriched in GO terms such as lipid metabolic process, small molecule metabolic process, and cellular response to chemical stimulus, with monocarboxylic acid metabolic process, modified amino acid metabolic process and aldehyde metabolic process following, and in KEGG pathways of carbohydrate, lipid and amino acid metabolisms, such as pentose and glucuronate interconversions, glycolysis/gluconeogenesis, glycerolipid metabolism, pentose phosphate pathways, fatty acid degradation, beta-alanine metabolism and arginine and proline metabolism. These findings provide functional and molecular evidence that L-carnosine can ameliorate HSF-induced disorders of carbohydrate and lipid metabolisms. Full article

Palmitoylation is a critical post-translational modification that involves the covalent binding of palmitic acid to cysteine residues within proteins. It is widely recognized that palmitoylation plays a significant role in regulating protein membrane localization, stability, and interactions. The kidney plays a key role in maintaining fluid homeostasis and excreting metabolic waste, and its normal function relies on the precise regulation of protein function. Emerging evidence reveals the crucial role of palmitoylation in renal physiological and pathological processes. However, the intricate pathways and molecular regulators in the kidney that are involved in palmitoylation remain insufficiently elucidated. This review summarizes the role and possible underlying physiological and pathological mechanism of palmitoylation in the kidney, including enzymes and inhibitors that regulate palmitoylation, the signaling pathways involved, target proteins involved in palmitoylation, and specific modification sites. Moreover, we focus on detection techniques and corresponding research strategies for palmitoylation. This review can also serve as a practical reference to improve the understanding of palmitoylation and the treatment of kidney-related diseases. Full article

Whole-cell biocatalysis presents a sustainable and efficient approach for the selective reduction in α,β-unsaturated bonds in flavonoid derivatives. This study investigates the capability of yeast strains from the Yarrowia clade to catalyze the chemoselective reduction of 4′-methoxychalcone (1a) to its dihydro derivative. All tested strains exhibited similarly high hydrogenation activity, indicating a broadly conserved enoate reductase function within the clade. Among them, Yarrowia lipolytica KCh 71, previously reported and well characterized in the literature, was selected for preparative-scale transformation of a diverse series of synthetic methoxychalcones bearing additional methoxy groups in positions C-2, C-3, C-4, C-5, and C-6 of ring B. All derivatives were effectively converted into the corresponding dihydrochalcones, with yields ranging from 62% to 92%. Among the tested derivatives, the 2′,4′,6′-trimethoxy chalcone (7a) did not undergo biotransformation under our conditions, whereas mono- and di-methoxy derivatives (2a–6a) were efficiently reduced. These results confirm the broad substrate tolerance, high efficiency, and potential scalability of Y. lipolytica KCh 71, supporting its potential as a whole-cell biocatalyst for the sustainable synthesis of bioactive dihydrochalcones. The consistently high hydrogenation activity observed across 21 tested strains suggests the involvement of evolutionarily conserved enoate reductases. Bioinformatic analysis supports that the Yarrowia clade possesses a robust complement of Old Yellow Enzymes (OYE), providing a reliable enzymatic basis for the observed chemoselective reductions. All Yarrowia tested strains showed the same general transformation type, although the extent and rate of conversion differed among strains, and Y. lipolytica KCh 71 was one of the most tolerant. The broad reduction in α,β-unsaturated chalcones is consistent with the action of flavoenzymatic ene-reductases, particularly Old Yellow Enzyme (OYE)–like reductases. Bioinformatic analysis of Yarrowia genomes reveals putative OYE homologs, supporting this mechanistic interpretation, although the specific enzymes were not identified in this study. Full article

Climate warming—a key driver of global change—significantly affects soil microbial communities and network stability. Biological soil crusts (biocrusts) help mitigate these impacts while maintaining soil ecological functions and biodiversity. However, how microbial networks and community dynamics respond to warming remains poorly understood between biocrust types, namely cyanobacterial and moss biocrust. In this study, we investigated the effect of warming on microbial communities and network stability in these biocrusts within the Mu Us Sandland, China. Using structural equation modeling (SEM), we found that warming altered microbial network properties: compared to the control, warming increased network vulnerability and decreased robustness specifically in cyanobacterial biocrusts. Warming and decreased soil moisture acted as strong filtering factors, resulting in lower microbial network stability. Although overall network complexity remained unchanged, warming reduced connectivity in cyanobacterial biocrusts, thus undermining network stability. Moreover, under both warming and control conditions, moss biocrusts exhibited lower robustness but higher vulnerability than cyanobacterial biocrusts, indicating cyanobacterial biocrusts displayed greater microbial network stability in comparison. Additionally, warming reduced the number of module hubs and keystone phyla in both biocrust types, decreasing key taxa abundance and weakening direct microbial interactions. We concluded that warming impaired microbial network stability by reducing connectivity in cyanobacterial biocrusts. These findings highlight the superior capacity of cyanobacterial biocrusts to sustain soil microbial network stability under climate warming and identify shifts in network connectivity as a central mechanism driving biocrust responses to environmental stress. Full article

Electrochemical sensors for oxyanion detection are widely reported across environmental, industrial, and biological contexts, with recent literature often emphasising material innovation and increasingly low detection limits. Despite this activity, translation beyond laboratory demonstrations remains limited, raising questions about how electrochemical signals are interpreted and validated. In this review, recent electrochemical oxyanion sensors are examined from a measurement-centred perspective, focusing on how signals are generated, conditioned, and calibrated across major sensing strategies, including direct faradaic detection, modified-electrode and electrocatalytic systems, accumulation-based approaches, and enzyme- or mediator-assisted architectures. Rather than cataloguing sensor materials or device configurations, the analysis examines the assumptions underlying commonly reported performance metrics. Across sensing strategies, signal behaviour is frequently governed by interfacial chemistry, surface history, and experimental constraints rather than by invariant properties of the target oxyanion. Consequently, sensitivity, selectivity, and detection limits often reflect context-dependent behaviour within narrowly defined laboratory regimes. By synthesising these patterns, the review identifies recurring interpretive limitations in how electrochemical responses are linked to analyte determination. The resulting framework clarifies the analytical basis of the existing literature and highlights design-relevant constraints and validation practices that must be addressed for electrochemical oxyanion sensors to progress from feasibility demonstrations to robust analytical tools. Full article

The market value of fragrant rice is largely defined by the presence and intensity of its aroma, which is primarily attributed to volatile compound 2-acetyl-1-pyrroline (2-AP). The biosynthesis of 2-AP is chiefly governed by recessive alleles of the badh2 gene. Nevertheless, 2-AP accumulation is also profoundly shaped by environmental factors and agronomic management. Field practices—such as balanced nitrogen and potassium fertilization, supplementation with trace elements, and application of plant growth regulators like methyl jasmonate—promote 2-AP synthesis by increasing precursor availability and enhancing the activity of key enzymes. Additionally, tillage systems, alternate wetting and drying irrigation, optimal planting density, and harvest timing significantly affect aroma quality. Abiotic stresses, including moderate drought, salinity, optimal temperatures around 25 °C, and low light during grain filling, can also stimulate 2-AP accumulation, often through shifts in proline metabolism and activation of stress-responsive pathways involving GABA and methylglyoxal. Despite the promise of these strategies, several challenges persist, such as the common trade-off between yield and aroma intensity, complex genotype-by-environment interactions, and incomplete elucidation of the molecular mechanisms involved. Moving forward, integrating multi-omics analyses with smart agriculture technologies will be essential to unravel the regulatory networks underlying aroma formation and to advance the breeding of high-yielding fragrant rice varieties with stable aroma traits under changing climate scenarios. Full article

This study investigated the effects of dietary chitosan supplementation at levels of 0, 0.5, 1, 2, 4, and 8 g/kg on the mud crab (Scylla paramamosain) during an eight-week feeding trial. Results revealed significant improvements in final body weight (FBW), weight gain rate (WGR), and specific growth rate (SGR) as chitosan levels increased, with the 2 g/kg group showing the strongest effects (p < 0.05). Chitosan supplementation also elevated crude protein content in the whole body, muscle, and hepatopancreas (p < 0.05). Moreover, it notably reduced malondialdehyde (MDA) levels in hemolymph and hepatopancreas while enhancing antioxidant enzyme activity (p < 0.05). Chitosan at doses of 1–4 g/kg also significantly increased the activity of non-specific immune enzymes in hemolymph (p < 0.05). Additionally, chitosan enhanced mRNA expression of immune-related genes in the hepatopancreas (p < 0.05). According to gut microbiota study, 2 g/kg chitosan raised the relative abundance of advantageous gut bacteria and modulated microbial composition. In conclusion, appropriate dietary chitosan supplementation successfully stimulates mud crab growth, strengthens immunological and antioxidant systems, and improves intestinal health. Full article

Liver fibrosis is driven by persistent oxidative stress and inflammatory signaling, with transforming growth factor-β (TGF-β) acting as a key profibrotic mediator. Rutin (Ru) is a plant-derived flavonoid with antioxidant and anti-inflammatory effects, but its low bioavailability limits therapeutic efficacy. This study investigated whether rutin-phytoreduced gold nanoparticles (RuAuNPs) enhanced rutin delivery leading to antifibrotic and anti-inflammatory effects in a rat model of liver fibrosis. Liver fibrosis was induced by oral administration of thioacetamide (TAA, 150 mg/kg body weight, p.o.) for six weeks. Following fibrosis induction, the animals were treated with free rutin (30 mg/kg body weight), RuAuNPs (0.3 mg/kg body weight), or AuNPs (0.3 mg/kg body weight), both expressed as nanoparticle mass, all administered orally for four weeks. RuAuNPs were synthesized by green rutin-mediated reduction and further characterized by TEM, DLS, and FTIR spectroscopy; they were spherical, showing an average hydrodynamic size of 104.1 nm (PDI 0.345). FTIR confirmed rutin capping. Biological effects were evaluated by liver morphology (H&E histology, TEM), biochemical assessment of liver aminotransferases and glico-lipidic status, ELISA and spectrophotometry measurement of redox biomarkers (lipid peroxidation, glutathione status, antioxidant enzymes), cytokines (TNF-α, IL-1β, IL-6), and TGF-β. TAA-induced hepatic injury and remodeling with increased profibrotic signaling, oxidative stress, and inflammation. Free rutin slightly ameliorated the liver damage, whereas RuAuNP improved histological features, reduced TGF-β and pro-inflammatory cytokines, decreased lipid peroxidation, and supported antioxidant defenses. Overall, RuAuNP may enhance rutin efficacy in TAA-induced liver fibrosis, with novelty stemming from the integrated in vivo evaluation of tissue changes and key profibrotic/oxidative/inflammatory pathway. Full article

Salinity is a major constraint on lettuce (Lactuca sativa L.) production and is known to inhibit seed germination. However, the physiological and biochemical processes underlying this sensitivity remain unclear. Therefore, this study aimed to investigate how salinity affects seed germination in two lettuce cultivars, ‘Susan’ (a highly salt-sensitive cultivar) and ‘Yafa’ (a low salt-sensitive cultivar), with particular emphasis on the roles of catalase and endo-β-mannanase enzyme activities. Seeds were subjected to both low salinity (0, 0.1, 0.2, 0.3, 0.5, 1, 3, and 5 mM NaCl) and high salinity (0, 10, 20, 40, 80, 160, and 320 mM NaCl) under standard germination conditions to evaluate germination percentage, mean germination time, and enzyme activity. Seedling emergence was also assessed in different growing media, including perlite, sand, peatmoss, and cocopeat. The results showed that salinity significantly reduced germination percentage and seedling length and increased mean germination time, with inhibition occurring at ≥0.1 mM NaCl in ‘Susan’ and ≥40 mM NaCl in ‘Yafa’; both cultivars failed to germinate at 320 mM. The ’Yafa’ had a high seedling emergence in all growing media, but ’Susan‘ seeds only emerged in perlite, which had the lowest salinity. Catalase activity increased markedly under salt stress, particularly in ‘Susan,’ indicating elevated oxidative burden, while endo-β-mannanase activity declined with increasing salinity, especially in the highly salt-sensitive cultivar of ‘Susan’. Correlation analysis showed that germination percentage had a significant and positive correlation with endo-β-mannanase activity and had a significant and negative correlation with catalase activity across salinity levels. In conclusion, salinity-induced inhibition of lettuce seed germination appears to be associated with changes in antioxidant enzyme activity and reduced endosperm weakening capacity, as reflected by altered catalase and endo-β-mannanase activities, thereby contributing to cultivar-dependent differences in salt sensitivity. Full article

Traditional enzyme-induced carbonate precipitation (EICP) technology for brick crack rehabilitation is commonly plagued by solution clogging and low repair efficiency. To overcome these technical limitations, a novel centrifugal cementation method was proposed in this study, with its core innovation lying in decoupling the EICP reaction from the masonry reinforcement process. After the complete reaction of urease with the cementation solution, a high-concentration calcium carbonate colloid was extracted via centrifugation, which was then mixed with fine sand to prepare a repair mortar for direct injection into brick cracks. The experimental results, based on a single-factor design with a fixed soybean powder concentration (180 g/L, peak urease activity), showed that the maximum flexural strength of the repaired bricks reached 2.31 MPa, recovering as much as 122.9% of that of the cracked unrepaired bricks. Furthermore, the flexural strength of the repaired bricks exhibited a significant positive correlation with the calcium carbonate content (20–100%) and curing time (3–28 days). Phase analysis indicated that the repair mortar was primarily composed of calcite and quartz. The high shear force generated by centrifugation triggered explosive nucleation of calcium carbonate, and spherical calcite particles were formed through Ostwald ripening, exhibiting a distinct characteristic of decoupling between the spherical morphology and calcite crystal phase. The centrifugal cementation method proposed in this study achieves excellent short-term repair effects for masonry structures under laboratory conditions, thus providing a novel technical approach for the crack rehabilitation of masonry structures. Full article

Cytomegalovirus (CMV) remains a major opportunistic pathogen in individuals with HIV. The aim of this study was to investigate the seroprevalence and reactivation rates of CMV among HIV-positive individuals. A total of 300 people with HIV presenting to the Istanbul Faculty of Medicine were enrolled. Serological assessments were performed using enzyme-linked immunosorbent assay (ELISA), while molecular analyses were conducted through PCR-based methods. Sociodemographic and clinical characteristics of the patients were also evaluated. Of the participants, 90% were male, with an age range of 18–76 years. Serological testing demonstrated CMV IgG positivity in 292 patients (97.3%) and CMV IgM positivity in 11 patients (4.07%). CMV DNA was detected in 91 patients (30.3%) by molecular assays, with viral loads ranging from <150 to 2,404,678 copies/mL. CMV DNA positivity was significantly more frequent in older patients (p < 0.05) and was associated with lower CD4+ T lymphocyte counts. CMV disease was identified in 50 patients (16.7%), with organ involvement (64%) representing the most common clinical manifestation. CMV seropositivity is remarkably high in HIV-positive individuals, and reactivation rates are increased, particularly in older patients and those with advanced immunosuppression. These findings underscore the clinical relevance of routine CMV surveillance in the management of HIV infection. Full article

Background/Objectives: Multiple Sclerosis (MS) is a chronic immune-mediated disorder characterized by neuroinflammation and neurodegeneration. Increasing evidence implies the kynurenine pathway (KP) in the MS pathophysiology; however, data from Mexican populations are lacking. This exploratory study aimed to characterize central and circulating KP metabolites in Mexican patients with MS and to investigate potential genetic variants in KP-related genes. Methods: Serum concentrations of kynurenic acid (KYNA) and 3-hydroxykynurenine (3-HK), as well as cerebrospinal fluid (CSF) levels of KYNA, quinolinic acid (QUIN), interleukin-4 (IL-4), and interleukin-6 (IL-6), were determined in treatment-naïve relapsing-remitting MS (RRMS), primary progressive MS (PPMS), and treated PMS patients. Serum levels were compared with those of healthy controls, and CSF findings contrasted with those of non-MS neurological patients and individuals with neurocysticercosis (NCC). Public whole-exome datasets were analyzed for variants in KP-related genes, and target exome sequencing was performed in three Mexican patients with MS. Results: Serum concentrations of KYNA and 3-HK were decreased in MS patients compared with healthy controls. CSF KYNA and QUIN levels did not differ significantly among MS subtypes or the non-MS neurological group, but they were lower than those observed in NCC. IL-4 and IL-6 were detectable in MS CSF samples, supporting the presence of intrathecal inflammation. Genetic and bioinformatic analyses identified variants in genes encoding KP enzymes in both public MS datasets and in Mexican patients with MS. Conclusions: These findings indicate an altered KP metabolism in Mexican MS patients, particularly during the relapse phase, and suggest a possible contribution of genetic variability. Further large-scale studies are needed to confirm these observations and to determine the functional implications of KP-related genetic variants in MS. Full article

The accumulation of microplastics (MPs) in agricultural soils and atrazine in agricultural soils creates compound pollution that severely threatens soil health. The present study aimed to evaluate the effect of polyethylene (PE), polyvinyl chloride (PVC), and polybutylene succinate (PBS) on the adsorption and degradation of atrazine in yellow-brown and black soil. Batch adsorption kinetic and isotherm experiments were conducted in two distinct soils amended with MPs. A 90-day degradation experiment was performed to monitor atrazine persistence and the activities of key soil enzymes. The adsorption process was best described by the pseudo-second-order model and the Freundlich isotherm model, suggesting dominant chemisorption and multilayer adsorption on heterogeneous surfaces of the soil–MP composites. All MPs significantly enhanced the adsorption capacity for atrazine (6.80–39.93 mg kg⁻¹), with the order PBS > PE > PVC. Furthermore, the degradation of atrazine was impeded by all MPs, with PVC exhibiting the strongest inhibitory effect. The half-life of atrazine ranges from 22.97 to 81.76 days in two soils. The presence of MPs also influenced soil enzyme activities and the effects varied by MP type and soil property. These results demonstrate that MPs can modify the adsorption and persistence of atrazine in soil, thereby increasing its environmental risk. This study provides valuable insights for the long-term ecological risk assessment of co-existing MPs and pesticide pollution in terrestrial environments. Full article

Background/Objectives: Clopidogrel is a widely prescribed antiplatelet prodrug that requires bioactivation, primarily by the polymorphic CYP2C19 enzyme. Genetic variation in this enzyme leads to differences in active metabolite formation and has prompted the development of pharmacogenetics-guided prescribing. However, current pharmacogenetic strategies are grounded in drug metabolism knowledge derived from mass balance studies conducted in small groups of healthy volunteers. This narrow evidence base may limit the data’s applicability to real-world settings, where factors like polypharmacy or altered organ function may influence drug response. Methods: Pharmacogenetics could benefit from real-world drug metabolism and excretion studies, which we conducted for clopidogrel in 38 kidney and 16 liver transplant recipients from the TransplantLines Biobank and Cohort Study (NCT03272841), utilizing existing LC-SWATH/MS pharmacometabolomic data. Clopidogrel-associated metabolic signals were identified using xenobiotic metabolism knowledge and literature-reported pathways. Results: Across both transplant groups, 26 clopidogrel-associated features were prioritized, of which some matched previously reported urinary metabolites, had previously been observed in plasma, or represented previously unreported metabolites. Clopidogrel carboxylic acid predominated in kidney transplant recipients, whereas its glucuronide form was most abundant in liver transplant recipients. Notably, unmetabolized clopidogrel was consistently detected across all patients. Moreover, our data support a thiol desulfurization route, aligning with emerging evidence of clopidogrel’s role as a hydrogen sulfide-releasing drug. Conclusions: More (putative) clopidogrel metabolites were detected than previously reported, demonstrating the value of pharmacometabolomics in expanding our understanding of drug metabolism. This approach provides novel data that may complement pharmacogenetics research to understand clopidogrel response variability among treated patients. Full article