Search Results (700)

Background/Objectives: Furan derivatives are commonly encountered in food and environmental matrices and may exert biological effects, but their acute cardiovascular actions and potential mitochondrial targets remain insufficiently characterised. This study examined the effects of two simple furan compounds, 2-acetylfuran (2AF) and 5-methylfurfural (5MFF), on arterial blood pressure in vivo and on oxidative phosphorylation in isolated rat liver mitochondria. Methods: Arterial blood pressure was recorded invasively in anaesthetised rats after intraperitoneal administration of 2AF or 5MFF (0.3 µL/g). Systolic, diastolic, and mean arterial pressures, as well as heart rate, were monitored over time. Mitochondrial respiration was assessed in isolated rat liver mitochondria using high-resolution respirometry. Results: Both 2AF and 5MFF induced a rapid hypotensive response, with significant reductions in systolic, diastolic, and mean arterial pressures within 10–15 min after administration. MAP was reduced to a similar extent by both compounds. However, their chronotropic and pulse pressure responses differed: 5MFF increased heart rate and pulse pressure, whereas 2AF induced a delayed bradycardic response without a significant change in pulse pressure. In isolated liver mitochondria, both compounds markedly reduced ADP-stimulated respiration and decreased the respiratory control index, indicating reduced coupling efficiency. Both compounds also increased the cytochrome c effect, suggesting partial impairment of outer mitochondrial membrane integrity. Conclusions: 2AF and 5MFF exert acute hypotensive effects in anaesthetised rats and impair oxidative phosphorylation in isolated rat liver mitochondria. This study provides the first in vivo evidence that 2AF and 5MFF exert hypotensive effects and identifies them as bioactive furan compounds with dual haemodynamic and bioenergetic actions. Full article

Sustainable lightweight materials based on renewable resources have attracted increasing attention as alternatives to synthetic materials. However, developing nanocellulose cryogels with adequate structural integrity and efficient retention of phenolic compounds remains challenging, often requiring furanic and dialdehyde-based additives associated with environmental and health concerns. In this context, tannin-containing nanocellulose cryogels were produced using vanillin and hydrogen peroxide as sustainable modification agents. The effects of the additives on the structural, morphological, colorimetric, mechanical, thermal, and leaching properties of the cryogels were investigated. FTIR and colorimetric analyses revealed the presence of phenolics and the effect of hydrogen peroxide. SEM analysis showed that tannin promoted structural densification, whereas peroxide induced fragmentation of the cryogel network and pore reorganization. These changes influenced density and mechanical performance, with nanocellulose-tannin exhibiting the highest compressive strength and elastic modulus. Thermal conductivity values remained within the range reported for highly porous lignocellulosic materials (38.93–43.79 (mW/m·K)). Tannin leaching demonstrated that peroxide significantly improved tannin retention, especially in the system including vanillin which exhibited only 13,61% tannin release. Overall, vanillin and hydrogen peroxide modified the supramolecular organization and functional properties of the cryogels, highlighting their potential as additives in porous materials for thermal insulation and adsorption applications. Full article

We report the synthesis, characterisation and electronic modulation of three novel fused polyheterocyclic ligands—naphtho[1,2-b]furan-4,5-dione (1), furo[3′,2′:3,4]naphtho[1,2-d]imidazole (2), and benzo[a]furo[2,3-c]phenazine (3)—and their Cu(II), Zn(II) and Fe(II/III) complexes. Compound (1) was isolated at 96.5% yield using fulvic acid as a green organocatalyst. ⁵⁷Fe Mössbauer spectroscopy identified two high-spin Fe(III) environments in a 37:63 ratio (δ = 0.377 mm s⁻¹; Δ = 0.62 and 1.01 mm s⁻¹), with no evidence of magnetically ordered oxide phases. Six enantiomeric metal malate salts were synthesised at 86–93% yield for spectrophotometric titrations. The key finding is a striking Cu(II)-specific enantioselective molecular recognition: (3) binds (S)-(−)-malate Cu(II) with log K = 9.02, a factor of 2.5× higher than the (R)-(+)-malate complex (log K = 8.62), while Fe(II) and Zn(II) show no enantioselectivity. These results establish chiral counter-ion engineering combined with π-conjugated polyheterocyclic scaffolds as a powerful strategy for chiroptical sensing and asymmetric catalysis. Full article

Hydrothermal liquefaction (HTL) is a promising route for converting wet biomass into bio-oil, but isolated model-component results do not necessarily describe naturally integrated lignocellulosic matrices. Here, lignin, cellulose, and hemicellulose were examined under subcritical HTL conditions (240–320 °C, 5–60 min, and water-to-biomass ratios of 2:1–20:1), and peanut shell and bamboo were used as two representative real feedstocks. At 300 °C and 30 min, lignin gave the highest bio-oil yield (45.36 wt%) and an oil enriched in phenolic compounds (>80% relative GC-MS peak area), whereas cellulose and hemicellulose gave lower oil yields (23.00 and 13.06 wt%, respectively) and larger aqueous-phase fractions. Oil-phase carbon and energy recoveries followed the order lignin (48.2% and 50.5%) > cellulose (32.4% and 35.9%) > hemicellulose (17.7% and 19.2%). A weighted additive reference constructed from the independent model-component results underpredicted phenolics and overpredicted carbohydrate-derived oxygenates in the real-biomass oils. For peanut shell and bamboo, the measured phenolic fractions were 68.85% and 64.11%, compared with additive-reference values of 47.66% and 34.17%, while the measured furanic fractions were 1.27% and 9.76%, compared with 12.12% and 17.88%. These directionally consistent deviations indicate non-additive product redistribution in the tested real-biomass samples. Full article

The chemical composition and sensory profile of coffee are influenced by brewing method, namely extraction pressure, temperature, contact time, and equipment. This study compared coffee prepared with a traditional moka pot, a conventional espresso machine, and a novel Italian device (Kamira). Volatile compounds were analyzed by headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography–mass spectrometry (GC–MS), leading to the determination of furan (34–42%), pyrrole (4–10%), and pyrazine (13–14%) derivatives. The most abundant fatty acids were palmitic (36–37%), linoleic (40%), and oleic (11%) acids. Physicochemical parameters (total solids, pH, and refractive index) were also measured. Caffeine and chlorogenic acids were quantified by liquid chromatography (HPLC). Differences in chlorogenic acids and volatile compounds were associated with variations in bitterness, acidity, astringency, and aroma intensity. Finally, a trained panel performed sensory evaluation to evaluate the olfactory and flavor attributes of the three types of coffee brews. Significant differences emerged among brewing systems. Espresso showed the highest caffeine content (55.3 ± 4.1 mg/100 g) and total solids (2.61 ± 0.11 g/100 g), together with a stable crema and intense sensory attributes. Moka coffee exhibited a rich aromatic profile but limited crema. The Kamira device produced an abundant crema and a chemical profile partially comparable to espresso. These findings confirm that brewing technology markedly affects coffee composition and sensory perception. Full article

This study aims to systematically investigate the combined effect of chemical activation of açaí seeds (Euterpe oleracea Mart.), with an aqueous sodium hydroxide (NaOH) solution at 2 mol·L⁻¹, and process temperature by pyrolysis of alkaline activated açaí seeds on the yield of reaction products (bio-oil, gas, H₂O, and biochar), physicochemical properties (acid value, density, and kinematic viscosity) and chemical composition (hydrocarbons and oxygenates) of bio-oil. Catalytic pyrolysis was carried out in a 143 L reactor at temperatures of 350 °C, 400 °C, and 450 °C, 1.0 atmosphere, operating in batch mode. The NaOH activation played a crucial role in modifying the thermal degradation pathway of the biomass, promoting the formation of specific chemical structures and altering the product yields. NaOH acted as a catalyst, enhancing the deoxygenation of the biomass and stimulating the formation of hydrocarbons. As a result, the yields of bio-oil, water, biochar, and gas varied from 5.77 to 7.20% (by mass), 14.90 to 19.77% (by mass), 41 to 54% (by mass), and 25.33 to 32.03%, respectively, influenced by the increase in temperature. FT-IR analyses indicated the presence of characteristic chemical functions of hydrocarbons (alkanes, alkenes, and aromatics) and oxygenated compounds (phenols, cresols, ketones, esters, carboxylic acids, aldehydes, and furans), with an intensification of hydrocarbon signals at higher temperatures. GC-MS analysis identified hydrocarbons and oxygenated compounds as the main chemical classes in the bio-oil, showing a strong dependence on pyrolysis temperature. It was observed that hydrocarbon concentration in bio-oil increased from 49.7% to 57.88% (area) with increasing temperature, while the concentration of oxygenated compounds decreased from 13.88% to 6.69% (area), demonstrating that NaOH activation, combined with temperature elevation, favors the formation of hydrocarbons and the reduction of oxygenated compounds, thereby improving the quality of the produced bio-oil. Full article

The fusion of heterocycles onto an anthraquinone scaffold represents a promising strategy to optimize anticancer activity. This study has the aim to synthesize and characterize novel anthra[1,2-b]furan compounds based on the natural product aloe-emodin. Six novel anthra[1,2-b]furans bearing phenyl, n-hexane, and methoxy carbonyl substituents were synthesized starting from aloe-emodin. The synthetic route employed involved acetyl protection of aloe-emodin, electrophilic aromatic halogenation, subsequent Castro–Stephens coupling, spontaneous intramolecular cyclization, and deprotection of hydroxyl groups. These newly synthesized compounds were evaluated for their cytotoxic activity against various cancer cell lines, including lung adenocarcinoma (A5492), colorectal carcinoma (HCT116), hepatocellular carcinoma (HepG2), ovarian cancer (Skov3), and breast cancer (MCF-7), using the CCK8 assay. The anthra[1,2-b]furan derivative 10c, which contains a methoxy carbonyl group, demonstrated excellent potency against lung (A549) and breast (MCF-7) cancer cell lines, with IC₅₀ values of 0.49 and 2.91 µM, respectively. This preliminary cytotoxic finding shows compound 10c as a promising hit for further investigations towards a promising lead compound. Full article

Quantifying the mixture effects on humans exposed remains challenging because mixture components are correlated and may act bidirectionally by exhibiting nonlinear dose-response relationships, which may contribute to subclinical organ dysfunction. The liver is a vital organ in the body with broad functions, making it vulnerable to injury as it is the first organ exposed to circulating toxicants, which can precipitate hepatic damage. Our study’s objective was to evaluate the combined and component-specific associations of a multi-chemical exposure mixture of heavy metals, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (dioxins), and polychlorinated dibenzofurans (furans), with liver biomarkers, and to compare concentration-based results with the toxic equivalent (TEQ) potency of the weighted results for dioxin-like compounds. In an unweighted analytic sample of U.S. adults from NHANES 2003–2004 with 947 complete cases, we examined heavy metals (cadmium, lead, and mercury), PCBs (12 congeners), dioxins (7 congeners), and furans (10 congeners) in relation to eight liver biomarkers (albumin, ALP, ALT, AST, GGT, LDH, total bilirubin, and total protein). We applied multi-exposure linear regression, weighted quantile sum (WQS) regression, quantile g-computation (qgcomp), and Bayesian kernel machine regression (BKMR), with parallel TEQ-based models using WHO 2005 TEFs for dioxin-like PCBs, dioxins, and furans. Across mixture methods, the mixture structure was chemically sparse, with a limited set of recurring contributors. Total bilirubin showed the most consistent positive mixture association across qgcomp and BKMR and persisted under TEQ weighting, with prominent PCB- and dioxin-like contributions (notably PCB81/PCB TEQs and dioxin-related components). Albumin demonstrated inverse mixture patterns in BKMR and TEQ-BKMR, with dioxin-like components (notably Dioxin3 and Dioxin3_TEQ) repeatedly emerging as key drivers. For ALT, ALP, AST, GGT, LDH, and total protein, overall mixture effects were frequently attenuated or null in qgcomp despite structured component weights, indicating bidirectional sub-mixtures and internal counterbalancing. BKMR PIPs similarly concentrated on a small number of dominant predictors (e.g., lead for ALP, mercury for ALT, PCB28 for AST, and cadmium and PCB189 for LDH), while interaction summaries provided limited evidence of stable non-additivity. Using multiple complementary mixture methods, we identified outcome-specific mixture patterns suggesting hepatobiliary vulnerability. TEQ concordance supports toxicological relevance of the dioxin-like axis, while metals and non–dioxin-like mechanisms likely contribute additional pathways. Full article

This study provides a comprehensive characterization of volatile and nonvolatile compounds in scallion-braised sea cucumber by integrating solid-phase microextraction gas chromatography-mass spectrometry (SPME-GC-MS) and widely targeted metabolomics. A total of 43 volatile compounds and 1792 nonvolatile metabolites were identified, with amino acids and their derivatives being the most abundant. Multivariate statistical analysis identified 11 key aroma-active volatiles and 619 significantly differential metabolites. Correlation network analysis demonstrated that characteristic flavors were primarily formed through coordinated pathways involving protein degradation, lipid oxidation, and carbohydrate metabolism during high-temperature braising. Terpenoids from seasonings, lipid-derived aldehydes and furans, and Maillard reaction products jointly shaped the distinctive aroma profile. This work clarifies the molecular mechanisms of flavor formation in scallion-braised sea cucumber and provides theoretical support for improving flavor regulation, processing standardization, and product quality evaluation in commercial sea cucumber production. Full article

The effect of cold smoking on the physicochemical, microbiological, and aromatic properties of Formaella-type cheese has not been previously investigated. In this study, experimental Formaella-type hard cheeses (≤38% moisture) were produced using a multistep high-temperature cooking process and subjected to weak (20 min) and intense (60 min) cold smoking, alongside an unsmoked control. Cheeses were analyzed before and after smoking and during refrigerated storage (up to 90 days). Smoking significantly influenced pH, water activity, and colour parameters, with intensively smoked cheeses exhibiting lower pH, reduced lightness (L*), and increased redness (a*) and yellowness (b*). Microbiological analyses revealed low viable counts across all samples, attributed to severe cooking steps and vacuum storage. Smoking, particularly at high intensity, significantly reduced total mesophilic counts and enterococci, while Enterobacteriaceae, staphylococci, yeasts, and moulds were not detected after manufacture. The dominant microbiota consisted mainly of lactic acid bacteria, identified by MALDI-TOF MS, including Enterococcus durans, Ent. faecium, Leuconostoc lactis, Leuconostoc mesenteroides, Streptococcus thermophilus, Lacticaseibacillus rhamnosus, and Lactobacillus curvatus. Headspace-SPME-GC-MS analysis identified 75 volatile compounds, with free fatty acids, ketones, aldehydes, and lactones as the predominant groups. Smoking introduced characteristic phenolic and furan derivatives associated with smoky aroma. Overall, smoking intensity modulated microbial dynamics and aroma development without compromising microbiological quality. Full article

Thamnaconus modestus (black scraper) is an economically important fish species in Chinese coastal fisheries, yet its pronounced fishy off-odor, primarily attributed to sulfur-containing compounds and trimethylamine (TMA), severely limits consumer acceptance and product diversification. However, a systematic investigation into how different thermal processing methods affect its volatile flavor profile is lacking. This study employed an integrated multi-instrumental flavoromics platform combining sensory evaluation, electronic nose (E-nose), electronic tongue (E-tongue), gas chromatography–ion mobility spectrometry (GC-IMS), and headspace solid-phase microextraction gas chromatography–mass spectrometry (HS-SPME-GC-MS), coupled with chemometric analysis, to systematically characterize the aroma variations of T. modestus subjected to steaming, boiling, deep-frying, and roasting treatments compared with raw samples. A total of 62 (GC-IMS) and 129 (GC-MS) volatile compounds were identified, from which 78 characteristic markers (VIP > 1) and 45 key odorants (OAV ≥ 1) were screened. Thermal processing markedly reduced sulfur-containing compounds and TMA concentrations (raw >> steamed ≈ boiled >> deep-fried > roasted) while promoting lipid oxidation- and Maillard reaction-derived aldehydes and furans. Two distinct flavor modulation patterns were revealed: moist-heat methods (steaming, boiling) generated grassy/fatty notes through moderate lipid oxidation, whereas dry-heat methods (deep-frying, roasting) produced characteristic roasted/nutty notes via synergistic activation of Strecker degradation and Maillard reaction. These findings provide scientific evidence for precise flavor quality control and diversified processing optimization of T. modestus products. Full article

Munronia pinnata (Meliaceae), a medicinal plant used in Zhuang traditional medicine, is recognized as a rich source of structurally diverse limonoids. In our continuing investigation of bioactive constituents from Guangxi medicinal plants, four new prieurianin-type limonoids, munropins G–J (1–4), were isolated from their aerial parts. Their structures were determined through comprehensive spectroscopic analysis, including nuclear magnetic resonance and high-resolution mass spectrometry, and further supported by quantum chemical calculations for electronic circular dichroism and statistical probability analysis. Munropins G (1) and H (2) feature an unprecedented C-12 β-D-glucosylated α-methyl-2′-hydroxypentanoate side chain and a C-17 β-substituted furan ring, with 1 being the 7-O-acetyl derivative of 2. Munropins I (3) and J (4) possess a formyl group at C-11, a 3-methyl-2-hydroxypentanoate ester at C-12, and a C-17 γ-hydroxy-α,β-unsaturated γ-lactone unit (21-hydroxy for 3, 23-hydroxy for 4), each existing as an equilibrating mixture of C-21 epimers—a phenomenon observed for the first time within a prieurianin-type framework. The absolute configurations of 1 and 2 were established by quantum chemical electronic circular dichroism calculations, while those of 3 and 4 remain to be assigned. All compounds were evaluated for cytotoxicity against human lung (A549), liver (HepG2), breast (MCF-7), and colon (HCT116) cancer cell lines and for anti-inflammatory activity in lipopolysaccharide-induced RAW 264.7 murine macrophages, but none exhibited significant effects at a concentration of 80 μM. This study expands the chemical diversity of Munronia limonoids and provides new molecular scaffolds for future structure–activity relationship investigations and chemotaxonomic markers for the Meliaceae family. Full article

Freshwater fungi have attracted considerable attention as a potential source of lead compounds with diverse and novel chemical structures and biological activities in drug discovery. This review summarizes 307 natural products of freshwater fungi from 1988 to the end of October 2025. These compounds are categorized into fourteen structural types, including fatty acids and their lactones (compounds 1–18), furans and furanones (compounds 19–31), pyrans and pyranones (compounds 32–109), benzoquinones, phenols and phenolic acids (compounds 110–141), naphthalenes and naphthalenones (compounds 142–192), authraquinones and xanthones (compounds 193–211, depsidones (compounds 212–217), macrolides (compounds 218–234), polyesters (compounds 235–237), alkaloids (compounds 238–251), peptides (compounds 252–280), terpenoids (compounds 281–300), steroids (compounds 301 and 302), and other compounds (compounds 303–307). Some of them displayed promising biological activity, mainly comprising antibacterial, cytotoxic, and nematicidal activities. The preliminary analysis of the Structure––Activity Relationship (SAR) of important compounds is also discussed. In the last section, current challenges and prospective research perspectives are briefly proposed based on opinions from previous reviews. This review would contribute to the understanding of the utilization and development of natural products derived from freshwater fungi as potent medical resources in the future. Full article

The valorization of agro-industrial byproducts through pyrolysis represents a sustainable route for generating multifunctional raw materials within the framework of a circular bioeconomy. In this study, rice husk (RH) and sugarcane bagasse (SCB) were pyrolyzed in a semi-continuous reactor at 500 °C in order to compare product yields and to characterize resulting gas, aqueous and tar fractions. SCB produced the highest bio-oil yield (44.2 wt%), whereas RH generated the highest char yield (42.9 wt%), consistent with its higher ash and lignin contents. In both cases, tar represented about 12 wt% of the bio-oil. Detailed characterization revealed that the liquid products contained oxygenated compounds of interest, mainly carboxylic acids, ketones, and phenols. Acetic acid was the predominant compound in the aqueous phases, while tars were composed mainly of phenols, ketones, furans, and acids. Particularly, phenols accounted for 52.6% and 37.8% of the total chromatographic area in RH and SCB tars, respectively, whereas ketones represented about 10% in both cases. These results show that pyrolysis of agro-industrial residues not only enables energy recovery but also provides liquid fractions enriched in value-added chemicals. Full article

This study investigated the influence of cocoa-bean amino acid profile on the formation of α,β-unsaturated carbonyls. Some of these heat-derived compounds generated primarily during roasting (often through Strecker degradation and aldol condensation) are of toxicological concern (e.g., the aneugenic 2-phenylcrotonaldehyde and the genotoxic furan-2(5H)-one). Here, their levels were compared by SAFE-GC/MS in cocoa of different origins, before and after roasting. Free amino acid profiles were determined by HPLC-MS/MS. All the investigated roasted beans showed similar total free amino acid contents (10.5–15.0 g·kg⁻¹) and profiles, while α,β-unsaturated aldehyde levels differed markedly between samples, and reached >200 µg·kg⁻¹ after roasting, indicating that amino acid availability alone does not govern their formation. Analysis of a commercial cocoa-free chocolate surrogate, however, revealed much lower amounts of both free amino acids (total 1.6 g·kg⁻¹) and amino-acid-derived α,β-unsaturated aldehydes (total 11 µg·kg⁻¹) than in chocolate, together with only traces of pyrazines (total 72 µg·kg⁻¹). In contrast, furan-2(5H)-one was found at similar levels in chocolate and the cocoa-free product (56–79 µg·kg⁻¹), confirming a completely different pathway where amino acids are not key reagents in its synthesis. Full article