Search Results (4,440)

Wood is a sustainable and renewable resource whose various uses include heating and manufacturing of various components for different sectors. The ever-increasing global demand for wood necessitates expanding the lifetime of wood products by reusing or recycling the wood into new products, for example in wood composites. To make the case for using preservative-treated wood to produce composites, this study investigates the capability of an unsaturated polyester matrix to encapsulate low-molecular-weight molecules. Ultraviolet-visible (UV-Vis) spectroscopy and gas chromatography–mass spectrometry (GC-MS) were used to study the leaching behaviour from wood composites upon storage in water. In a first step, the wood used for the wood composites was treated with UV-active model compounds (uranine and Nile red), combined with resin to make wood composites, and their leaching into water was determined by UV-vis spectroscopy. In the GC-MS study, a similar experimental setup was used to study the leaching of wood preservatives (tebuconazole, propiconazole, and permethrin) over time from wood composites. The leaching of the wood preservatives from the wood composites upon water storage was assessed and quantified using GC-MS. The study found that the majority of the studied compounds only leach to a very small extent from the wood composites. Possible reasons for variations in leaching behaviour are discussed. These findings are an important first step in the endeavour of reusing contaminated wood in wood composites. Full article

Edible fungal polysaccharides have been recognized as low-toxic natural candidates for tumor adjuvant therapy by regulating gut microbiota and host metabolism. This study aimed to prepare an S. luteus alkali-extracted (pH = 9) polysaccharide (SLP9) via optimized extraction and systematically elucidate the anti-tumor effects based on polysaccharide structure, genus-level gut microbiota and fecal metabolomics. Structural characterization via high-performance gel permeation chromatography (HPGPC), gas chromatography-mass spectrometry (GC-MS) and Fourier-transform infrared spectroscopy (FTIR) verified that SLP9 possessed abundant β-glycosidic linkages with a Xyl:Man:Glc:Gal molar ratio of 0.52:1.00:0.81:0.57 and an average molecular weight of approximately 1.58 × 10⁷ Da. An in vivo anti-tumor experiment revealed that high-dose SLP9 exhibited obvious tumor inhibition with an inhibitory rate of 40.28% via restoring microbial diversity and selectively enriching the beneficial genus Lactobacillus, which might be relevant with activating three top significant KEGG pathways tropane, piperidine and pyridine alkaloid biosynthesis, arginine biosynthesis, alkaloid biosynthesis from ornithine, lysine and nicotinic acid. Collectively, this study systematically revealed the intrinsic correlations between the SLP9 extraction process, structural characteristics, targeted regulation of intestinal microbial metabolism and anti-tumor activity. These findings provide comprehensive theoretical support for using SLP9 as a new microecological regulator for tumor adjuvant therapy. Full article

Antimicrobial resistance is a growing global health challenge, highlighting the need for new bioactive compounds from medicinal plants. Vepris nobilis is traditionally used in East Africa for treating infections and respiratory disorders; however, its essential oil (EO) composition and antimicrobial mechanisms remain poorly characterized. This study investigated the chemical composition and antimicrobial activity of V. nobilis EO, along with an in silico evaluation of its major constituent, germacrene D. The EO was extracted by hydrodistillation and analyzed using gas chromatography-mass spectrometry (GC–MS). Its antimicrobial activity was evaluated against 26 bacterial and 4 fungal strains using disc diffusion, broth microdilution, and MBC/MFC (Minimum Bactericidal Concentration/Minimum Fungicidal Concentration) assays. Germacrene D showed stronger activity than the EO, particularly against both multidrug resistant (MDR) and non-MDR Gram-negative bacterial strains (MIC = 10 µg/mL), with bactericidal and fungicidal effect. Molecular docking of germacrene D against two clinically relevant enzymes—dehydrosqualene synthase (CrtM) from Staphylococcus aureus and SWISS-modeled sterol 14-α-demethylase (CYP51) from Penicillium funiculosum—suggested potential interactions with both targets, with a favorable predicted binding affinity for CrtM (−7.654 kcal/mol) and for CYP51 (−5.898 kcal/mol). These findings provide preliminary insights into a possible antimicrobial mechanism, although experimental validation is needed to confirm this hypothesis. ADMET analysis suggested favorable drug-like properties despite limited solubility. These findings provide scientific support for the traditional use of V. nobilis leaves in the treatment of respiratory infections and highlight germacrene D as a promising lead compound for further antimicrobial development. Full article

The global reliance on commodity oils has intensified the search for alternative plant-based sources capable of meeting increasing worldwide demand. The utilization of fruits from the Brazilian Savanna and their associated byproducts offers numerous possibilities, as these native species are rich in nutrients and bioactive compounds with nutraceutical potential. However, gaps remain in the characterization of their lipid profiles, particularly with respect to processing residues. Therefore, the objective of this study was to investigate the fatty acid profiles of various parts of araticum (Annona crassiflora), baru (Dipteryx alata), buriti (Mauritia flexuosa), and pequi (Caryocar brasiliense) fruits using gas chromatography coupled with mass spectrometry (GC–MS). The total content of monounsaturated fatty acids exceeded that of saturated fatty acids in residues, including baru pulp and peel, buriti peel, and pequi seed. Notably, essential fatty acids were abundant in the fruit side streams, with omega-9 fatty acids particularly abundant in buriti peel. Baru seeds were notable for their high omega-6 fatty acid content, which was also observed in the pulp and peel of baru. Lipid quality indices (AI, TI, h/H, and HPI) varied substantially among fruit fractions. The lowest TI values were observed in buriti peel (0.2) and pequi pulp (0.2), while high h/H and HPI values were found in buriti peel (155.8 and 46.5, respectively), pequi pulp (133.4 and 48.6, respectively), and araticum seed (48.8 and 13.3, respectively). These results indicate favorable lipid quality characteristics in some fruit fractions and highlight the potential of these byproducts as alternative sources of nutritionally relevant lipids. Their utilization may also support sustainable and responsible consumption, provide additional income opportunities for producers, and contribute to biome preservation. Further biological and clinical studies are needed to determine whether these lipid characteristics translate into measurable health effects. Full article

Halogenated ketones (HKs) and aldehydes (HAs) are prevalent emerging disinfection by-products (DBPs) threatening drinking water safety. Although pre-oxidation and coagulation are widely applied in drinking water treatment, critical knowledge gaps remain regarding the precursor-specific effects of KMnO₄ and O₃ pre-oxidation on chlorinated ketone/aldehyde formation potential, as well as the interaction between coagulation optimization and DBP yields. This study systematically investigates the effects of KMnO₄/O₃ pre-oxidation and optimized coagulation on the formation potential (FP) of 1,1-dichloroacetone (1,1-DCP), 1,1,1-trichloroacetone (1,1,1-TCP), and chloral hydrate (CH) from four typical precursors (fulvic acid, citric acid, L-threonine, L-asparagine). Batch pre-oxidation and chlorination experiments were performed; three-dimensional excitation–emission matrix (3D-EEM) fluorescence spectroscopy was used to characterize organic-precursor structural changes, while gas chromatography–mass spectrometry (GC-MS) was adopted to quantify target DBPs. Results show that KMnO₄ and O₃ pre-oxidation significantly promote (p < 0.05) DBP formation from fulvic acid but exert precursor-specific effects on small-molecule precursors: KMnO₄ enhances CKs while inhibiting CH from amino acids, and O₃ suppresses all three DBPs from small-molecule precursors. Coagulation pretreatment weakly inhibits DBP formation (reduction rate < 20%) by removing partial precursors. This study clarifies the mechanism of process-driven DBP modulation and provides a theoretical basis for optimizing water treatment processes to control chlorinated ketone/aldehyde DBPs. Full article

Agricultural soils have been identified as significant sinks for plastic waste from mulch films, which in turn can reach aquatic ecosystems. As an alternative to conventional materials, there has been growing interest in biodegradable mulch films, but their environmental behavior and ecotoxicological effects are not yet fully established. In this study, the effects of residues from a conventional mulch film and a biodegradable mulch film on model organisms representative of edaphic (Hordeum vulgare and Cucurbita maxima) and aquatic (Paracentrotus lividus) ecosystems were evaluated. During this study, the residues of the mulches in seawater were also analyzed, considering natural aging conditions, using pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS). The results of the ecotoxicological tests showed that the residues of both types of mulch films did not generate any significant adverse effects on the selected terrestrial and marine bioindicators in the two end-of-life scenarios, with the exception of the residues of conventional mulch, unaged and aged for one month, at medium-high concentrations from an environmental point of view on P. lividus. The natural weathering assay in a marine environment showed that residues from conventional mulch film remained essentially unaltered, with similar concentrations detected throughout the 12-month exposure period. In contrast, the biodegradable mulch film exhibited significant degradation from the initial time point, reaching concentrations below the analytical detection limit after the first month. Full article

The chemical profile and migration behavior of volatile and semi-volatile compounds from silicone molds intended for use in air fryers were investigated. The study combined migration tests using 10% ethanol, 3% acetic acid, and simulant E (Tenax^®) with direct headspace (HS) analysis of the molds by gas chromatography–mass spectrometry (GC-MS). HS analysis and migration tests with aqueous simulants were performed over three heating cycles to simulate repeated use. A non-targeted analytical approach was applied, followed by selective quantification based on toxicological criteria and the relevance of the compounds to the material. A total of 128 substances were identified, including siloxanes and non-intentionally added substances (NIASs). Siloxanes were detected in both simulant E and 10% ethanol. Most NIASs were found at levels below the limit of quantification or within regulatory limits, except for dibutyl phthalate, which exceeded its specific migration limit (0.3 mg kg⁻¹). Furthermore, the sum of migrated cyclic siloxanes in simulant E surpassed the generic specific migration limit (60 mg kg⁻¹) established in Spanish Royal Decree 847/2011, while the release of volatile organic compounds exceeded the recommended value of 0.5%. The results revealed a complex chemical profile characterized by diverse NIASs and elevated migration of cyclic siloxanes in simulant E. Full article

Floral volatile organic compounds (VOCs) play a key role in chemical communication between plants and pollinators. Given the limited understanding of the chemical signals involved in the interactions among Passiflora edulis Sims (Passifloraceae), Poincianella pyramidalis (Tul.) L.P. Queiroz (Fabaceae), and Xylocopa (Neoxylocopa) nigrocincta Smith (Hymenoptera: Apidae), this study aimed to identify the floral VOCs emitted by these plant species and evaluate their detection by the antennae of X. nigrocincta. Floral VOCs were collected using dynamic headspace sampling, adsorbed in Porapak Q, and eluted with 500 µL of hexane. The resulting extracts were analyzed by gas chromatography with flame ionization detection (GC-FID), gas chromatography–mass spectrometry (GC–MS), and gas chromatography coupled with electroantennographic detection (GC–EAD). A total of 23 compounds were identified, six of which were shared by both plant species. The chemical profiles differed markedly: P. edulis was characterized mainly by methoxylated ethers and esters, whereas P. pyramidalis showed a predominance of terpenes. 1,4-dimethoxybenzene, the major compound in P. edulis, and (E)-β-ocimene, the most abundant compound in P. pyramidalis, elicited electroantennographic responses in X. nigrocincta, demonstrating that both compounds are detected by the olfactory system of these bees. These findings reveal differences in the floral VOC profiles of the two plant species and identify compounds detected by X. nigrocincta, providing a basis for future behavioral studies to investigate the role of these volatiles in plant–pollinator interactions. Full article

Carya illinoinensis (pecan) has recently emerged as a promising oilseed crop in Eastern Europe; however, its oil has not been systematically characterized under regional growing conditions or directly compared with that of the established nut crop, Juglans regia (walnut). This study evaluated the proximate composition, fatty acid profile, and short-term oxidative stability of oils from six pooled sample groups, comprising three pecan and three walnut composite samples collected from Romania and the Republic of Moldova. Oils were extracted by hot pressing, kernel composition was determined using standard official (AOAC) methods, fatty acid composition was analyzed by gas chromatography–mass spectrometry (GC–MS), and oxidative stability was assessed by peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) during 20 days of storage. Romanian pecan oils contained 67–68% total fat and were rich in linoleic acid (55–57%), whereas walnut oils contained 59–61% fat and were dominated by oleic acid (57–58%). The PNC composite sample exhibited an oleic acid-dominant profile that differed from those of the other two pecan samples. Because cultivar identity, genotype, and environmental variables were not determined, the cause of this difference cannot be established from the present study. All samples remained below the Codex Alimentarius PV limit (3.0 meq O₂/kg). TBARS changes differed among the analyzed composite oils; however, these differences cannot be attributed solely to fatty acid composition because antioxidant constituents were not measured. Oleic and linoleic acids were strongly and inversely correlated (Pearson r = −0.9998, p < 0.001). These findings provide the first comprehensive characterization of pecan oil produced under Eastern European conditions and demonstrate compositional variation among the analyzed composite samples, although the factors responsible for this variation could not be determined. Full article

The current clinical test for ketosis in dairy cows, which is based on measuring blood β-hydroxybutyrate (BHB) concentrations, is an invasive procedure that impacts herd welfare. Alternative biomarkers, especially non-invasive ones, are urgently needed for subclinical ketosis (SCK) diagnosis. To address this, we examined the milk lipidomic profiles of healthy and SCK cows from a research dairy farm over two consecutive years. A total of 125 polar lipid species were quantified in milk samples using a targeted liquid chromatography–mass spectrometry (LC-MS) approach. Chemometric analysis identified four potential biomarkers (PC 28:0, PC 29:0, PC 30:1 and PC 31:0), which met the thresholds for p value (<0.0004) and fold change (FC > 2). Global fatty acid (FA) profiling by gas chromatography–flame ionization detection (GC-FID) after transesterification of all lipids revealed that the levels of C8:0, C10:0, C12:0, C14:0, C15:0 and C18:1t11 were significantly suppressed in the SCK group (15–52% lower compared to the control group, p < 0.01), and C15:0 and C18:1t11 were the most promising markers for SCK in dairy cows at the FA level (43–50% reduction compared to the control group, p < 0.0001). Tandem LC-MS and FA data generated by GC demonstrated that SCK also caused significant changes in regio-isomer and double bond isomer composition of a model phospholipid molecule (PC 34:1) and a model triglyceride molecule TAG 52:2; these fine-structural alterations could also be explored for discovering novel SCK biomarkers in dairy cows. The PLS-DA predictive model built from lipidomic data showed excellent accuracy (>95%) in predicting cows with SCK. All of the promising biomarkers identified and the predictive model built in this study need further validation using larger SCK cohorts from different herds. Full article

Organophosphorus pesticides (OPs) are persistent environmental contaminants requiring monitoring in aquatic ecosystems. In this study, four novel mineral–carbon composites (K-HNT, K-C-HNT, D-HNT, and D-C-HNT) were synthesized via thermal treatment at 800 °C from halloysite nanotubes, casein, dextrin, and pyrolyzed sawdust. Moreover, these materials were characterized (BET, FT-IR, Raman, SEM/EDS), revealing high specific surface areas (up to 218.3 m²/g for the D-C-HNT composite), and evaluated as solid-phase extraction (SPE) sorbents for the determination of six OPs from water. The eluates were analyzed using GC-MS/MS in MRM mode. This study examined the effect of eluent, sorbent mass, and multiple extractions on SPE efficiency. Ethyl acetate-n-hexane (1:1, v/v) was confirmed to be the most effective eluent, achieving high pesticide recoveries (>80%) at optimal sorbent masses of 50 and 75 mg. The method demonstrated satisfactory sensitivity, with limits of detection (LODs) ranging from 1.6 to 3.3 μgL⁻¹. Notably, the synthesized composites outperformed pure precursors and demonstrated extraction efficiency comparable to commercial sorbents (C-18, Florisil, active carbon). Furthermore, reusability tests confirmed that second and third extraction repetitions reduced the efficiency of the SPE process only slightly, indicating that these waste-derived composites can be reused multiple times without cartridge replacement. Full article

Background/Objectives: The increasing prevalence of antimicrobial resistance has reduced the effectiveness of conventional antibiotics, highlighting the need for alternative or adjunct antimicrobial agents. This study aimed to investigate the antibacterial, synergistic, and antibiofilm activities of Liquidambar orientalis Mill. essential oil against clinically relevant bacterial pathogens, using 24 bacterial strains representing 12 bacterial species. Methods: The volatile constituents of L. orientalis essential oil obtained by hydrodistillation of storax balsam were characterized by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC-FID). Antibacterial activity was evaluated using minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), disk diffusion, and agar well diffusion assays against a panel of Gram-positive and Gram-negative bacterial pathogens. Synergistic interactions with erythromycin, amoxicillin, gentamicin, and enrofloxacin were assessed using fractional inhibitory concentration index (FICI) analysis. Antibiofilm activity was also evaluated against representative biofilm-forming strains. Results: A total of 90 volatile constituents were identified by GC-MS, of which styrene was the most abundant (68.6%), followed by (E)-ethyl cinnamate (6.8%), α-pinene (5.9%), and β-pinene (2.9%). The essential oil exhibited broad-spectrum antibacterial activity, with an overall inhibition rate of 60.4%. Activity was higher against Gram-positive (77.77%) than Gram-negative (73.33%) bacteria. MIC and MBC values ranged from 15.62 to 250 µg/mL and 31.25 to 250 µg/mL, respectively. FICI analysis revealed strain- and antibiotic-dependent interactions, ranging from synergistic to antagonistic effects. Variable antibiofilm activity was observed, with the strongest inhibition against Brucella melitensis and the weakest against Pseudomonas aeruginosa. No significant differences in MIC or MBC values were observed between bacterial groups (p > 0.05). Conclusions: L. orientalis essential oil demonstrated in vitro antibacterial activity against several clinically relevant pathogens, with particularly notable activity against B. melitensis. The essential oil also showed synergistic interactions with selected antibiotics and variable antibiofilm effects. These findings suggest that L. orientalis essential oil may have potential as an antibacterial agent or adjunct to antibiotic therapy; however, further in vivo and clinical studies are required to confirm its therapeutic applicability. Full article

A rare carved lacquer (tixi) plate recovered from the Southern Song Dynasty Nanhai No. 1 shipwreck was examined to reconstruct its coating stratigraphy, raw materials, and manufacturing sequence. Detached fragments collected before conservation treatment were investigated by cross-sectional optical microscopy, micro-Raman spectroscopy, thermally assisted hydrolysis–methylation pyrolysis–gas chromatography/mass spectrometry (THM-Py-GC/MS), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), and wood-anatomical microscopy. The polished cross-section contains nine lacquer layers with a combined thickness of 387.3 μm above a heterogeneous ground, yielding ten visually distinguishable strata. Alternating dark, red, and yellow layers establish the technological basis for the carved polychrome effect. Raman bands identify cinnabar (HgS) in the red layer and orpiment (As₂S₃) in the yellow layer. THM-Py-GC/MS detected homologous alkenes, alkanes, and alkylbenzenes diagnostic of Chinese lacquer derived from Toxicodendron vernicifluum. Monocarboxylic acids were present, whereas no clear dicarboxylic-acid markers of a drying oil were observed; because the object was waterlogged and degraded, this absence is treated as a lack of positive evidence rather than proof that oil was never used. The ground is enriched in Ca and P and is therefore consistent with a bone-ash-based filler, although phase-specific confirmation remains necessary. Wood anatomy identifies the substrate as Chinese fir (Cunninghamia lanceolata, Cupressaceae). Together, the results document an organic–inorganic multilayer coating system and provide material evidence for Southern Song carved-lacquer technology, while defining conservation risks associated with a waterlogged wooden core and light-sensitive pigments. The marine archaeological context and the support-to-surface, layer-resolved design distinguish this case from most previous studies of Song-dynasty lacquerware. Beyond technological reconstruction, the findings identify conservation priorities for waterlogged wood, the wood–ground–lacquer interface, and light-sensitive pigmented layers, and provide a transferable evidence framework for comparative research on archaeological lacquer. Full article

The Potiguar Basin, in Rio Grande do Norte (Northeastern Brazil), has an extensive coastline with a rich diversity of marine sponges that remain poorly explored for their biotechnological potential. In this study, three sponge species—Suberites aurantiacus, Mycale (Zygomycale) angulosa, and Halichondrida—were collected, and a preliminary extraction was then performed to remove the most hydrophobic fraction with n-hexane. The remaining sediment was re-extracted with chloroform and methanol (1:1), and the resulting extracts (ESUB, EMYC, and EHALI, respectively) were analyzed. Chemical characterization using Gas–Liquid Chromatography–Mass Spectrometry (GC/MS) revealed distinct profiles for each genus, with the presence of alcohols, alkaloids, phenolic compounds, and lipids, mainly sterols. ESUB presented 17 identified compounds, EMYC had 15 identified and EHALI showed 15 identified. The antioxidant potential of the extracts was evaluated in vitro using DPPH radical scavenging, copper ion chelation, and total antioxidant capacity (TAC). The EC₅₀ values (mg/mL) for DPPH were 0.05 (ESUB), 0.14 (EMYC), and 0.06 (EHALI), while for copper chelation they were 0.03, 0.034, and 0.026, respectively. Preliminary toxicological assays indicated low toxicity, with IC₅₀ values above 9.6 mg/mL in human erythrocytes and Tenebrio molitor larvae, demonstrating a favorable safety profile for potential therapeutic applications. The study presents a preliminary screening of underexplored species in an equally underexplored region and supports further studies on their bioactive potential. Full article

Background/Objectives: This study presents a gas chromatography–mass spectrometry (GC–MS) method for the derivatization-free quantification of the three major short-chain fatty acids (SCFAs)—acetate, propionate, and butyrate—in gilthead sea bream (Sparus aurata) fecal samples. SCFAs are key metabolites involved in intestinal physiology and are widely recognized as indicators of gut microbiota activity and host health across animal species. In aquaculture research, SCFA profiling can provide valuable insight into diet–microbiota interactions and gut functional status. Methods: The method was developed and optimized using gut-content samples collected from 105 gilthead sea bream at the end of two independent feeding trials, yielding 42 pooled samples (18 from FT1 and 24 from FT2). An extraction protocol based on acidified aqueous extraction with water followed by liquid–liquid extraction using methyl tert-butyl ether was developed (ExA) and subsequently optimized (ExB) to improve extraction consistency and efficiency. SCFA separation and quantification were performed by GC–MS using external calibration. Method validation included evaluation of linearity, matrix effects, and partition coefficients between water and methyl tert-butyl ether. Results: The optimized extraction method (ExB) demonstrated high analytical performance, with linearity coefficients exceeding 0.992 and matrix effects below 17.4%. Conclusions: The proposed method represents a practical and reliable approach for routine SCFA analysis in fish fecal samples. It provides a useful analytical tool for studies investigating diet–microbiota interactions, gut health, and functional responses to nutritional interventions in aquaculture species. Full article