Search Results (508)

Despite its rich bioactive composition, orange peel dust (OPD), a fine industrial by-product generated during citrus processing in the filter tea industry, has not received much attention as a valuable matrix. Using antioxidant activity (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and reducing power (RP)), α-amylase inhibitory activity, antimicrobial potential, and sugar composition as function-oriented indicators, this study aimed to compare four green extraction technologies: subcritical water extraction (SWE), pressurized ethanol extraction (PEE), ultrasound-assisted extraction (UAE), and sequential supercritical CO₂–UAE (Sc-CO₂–UAE) applied to OPD derived from Citrus sinensis L. Among thermally driven techniques, PEE at 220 °C had the highest radical-scavenging activity, while UAE showed the broadest antifungal activity against Fusarium spp. and Alternaria alternata, along with selective antibacterial activity against Bacillus cereus. Sequential Sc-CO₂ pretreatment at 300 bar followed by UAE resulted in the highest α-amylase inhibitory activity. Sugar analysis indicated that thermal conditions enhanced carbohydrate hydrolysis, while UAE and Sc-CO₂-UAE maintained structural sugars under mild conditions. All green extraction approaches outperformed conventional maceration. These findings validate OPD as a valuable industrial by-product suitable for sustainable valorization, supporting circular economy concepts in the citrus processing sector. Full article

Perfluorosulfonic acid (PFSA) membranes, exemplified by Nafion, suffer dehydration-induced degradation at elevated temperatures, although modifications enhance their conductivity and performance. Sulfonated aromatic polymers (SAPs) exhibit weaker phase separation, yielding narrow, tortuous ion channels and lower conductivity than their PFSA membrane counterparts at equivalent ion exchange capacity; however, excessive sulfonation causes swelling and mechanical instability, offset by cost advantages. Phosphoric acid-doped polybenzimidazole (PBI) offers superior thermal stability and high conductivity, with recent advances in polybenzimidazole derivatives and composites driving medium-to-high temperature proton-exchange membrane fuel cell innovation. This review summarizes progress in three major medium-to-high temperature proton-exchange membrane fuel cell categories—perfluorosulfonic acid, sulfonated polymers, and PBI-based membranes—while addressing challenges and future goals for enhanced performance. Full article

Aqueous redox flow batteries (ARFBs) are a promising solution for large-scale energy storage; however, the development of organic posolytes that combine high redox potential with long-term stability remains a significant hurdle. This study introduces sodium 3-(10H-phenoxazin-10-yl)propane-1-sulfonate (POZS), a novel sulfonate-functionalized phenoxazine derivative designed to overcome these limitations. By incorporating hydrophilic anionic sulfonic groups, this molecular engineering strategy enhances the structural stability of redox-active phenoxazine materials. Although POZS shows limited solubility in pure water, its solubility increases to 0.98 M (equivalent to a charge capacity of 26.3 Ah L⁻¹) upon the addition of 1.5 M tetraethylammonium chloride (TEAC). This enhancement suggests that the supporting electrolyte optimizes the ionic environment and mitigates intermolecular aggregation, thereby facilitating higher active species concentration. Electrochemical characterization of POZS reveals a highly positive redox potential of 1.51 V (vs. Zn/Zn²⁺) and rapid electron transfer kinetics (2.02 × 10⁻² cm s⁻¹). When tested in a zinc-based hybrid flow cell, the POZS posolyte demonstrates excellent rate capability (up to 50 mA cm⁻²) and a temporal capacity fade rate of 0.335% per hour over 500 cycles—a nearly five-fold improvement over previously reported quaternized phenoxazines. Post-cycling analyses indicate that while the phenoxazine core remains susceptible to nucleophilic ring substitution, the pendant sulfonate groups ensure that any resulting byproducts remain soluble, preventing the catastrophic depletion typically caused by the precipitation of degraded active species. These findings establish a robust molecular framework for the design of high-potential, durable organic posolytes for sustainable energy storage systems. Full article

Human serum albumin (HSA) is the most abundant protein in plasma, and the redox state of circulating HSA has been used as a biomarker of systemic oxidative stress (OS) for decades. While informative, many traditional biomarkers of OS measure short-lived or downstream products of oxidative damage that offer limited perspectives on the dynamic and integrated processes that govern systemic redox biology within human populations. By moving beyond single-analyte damage markers and towards coordinated patterns of protein modifications, HSA-Cys³⁴ adductomics offers a systems-level approach that simultaneously captures change in multiple layers of OS. Because of its high abundance in plasma and HSA’s unique and highly reactive single free thiol (Cys³⁴), HSA-Cys³⁴ serves as an ideal sentinel target for monitoring reactions with reactive oxygen species (ROS), reactive nitrogen species (RNS), and electrophilic species produced by endogenous metabolism and responses to exogenous chemical exposures. The reaction of HSA with ROS, RNS, and reactive electrophiles yields a diverse array of protein modifications, including direct oxidation products (sulfenic, sulfinic, and sulfonic acid), low molecular weight thiol-disulfide exchange, and lipid peroxidation (LPO)-derived reactive aldehydes. With a mean residence time of about a month, these accumulated adducts serve as an integrated picture of oxidative and electrophilic stress that together function as a molecular record of systemic redox physiology. Previous studies using high-resolution mass spectrometry-based adductomics have enabled global untargeted analysis of HSA-Cys³⁴ modifications, yielding an expansive inventory of novel redox signatures of environmental stressors and disease states. In this paper we review the chemistry and biology underlying OS-related modifications of HSA-Cys³⁴ and highlight the important role of HSA-Cys³⁴ adducts as integrative biomarkers of OS at the interface of molecular biology, exposure assessment, and public health research. Full article

Sulfur fumigation, as a highly effective method for preservation and appearance enhancement, has been widely applied in fruits, vegetables, and food products. However, excessive sulfur fumigation can pose safety risks. Currently, there is limited research on the bound sulfites produced by sulfur fumigation, and no consensus has been reached regarding their structure and toxicity. Using ultra-performance liquid chromatography–quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS), a total of 34 compounds were identified in 12 lily bulb samples subjected to different sulfur fumigation durations. These derivatives were all hypothesized to form via nucleophilic addition to carbon–carbon double bonds. Based on multivariate statistical analysis, 9 characteristic markers were established to rapidly differentiate between non-fumigated (NF) and sulfur-fumigated (SF) samples. The practicality of this strategy was validated using 18 commercial batches. Molecular docking simulations predicted that the modifications might enhance toxicity toward liver injury-related targets, both by altering the spatial conformation of the compounds and because the sulfonic acid group itself serves as an ideal hydrogen-bond acceptor. Overall, mild fumigation led to a gradual accumulation of free sulfur dioxide in lily bulbs, increased the total content of phenolic components and antioxidant capacity, and did not generate excessive bound sulfur dioxide. However, with further extension of fumigation time, the content of sulfur-containing derivatives rose rapidly, accompanied by a noticeable decline in antioxidant activity. This study elucidates the sulfur-driven chemical transformation mechanisms in lily bulbs and establishes a targeted methodology for the quality control and safety assessment of processed herbal products. Full article

Moringa oleifera leaves are recognized as a nutrient-dense plant material of compositional and nutritional interest. This study aimed to characterize the nutritional and physicochemical properties of M. oleifera dried leaves through nutritional assessment and spectroscopic fingerprinting. Amino acid profiling, antioxidant activity assessment using ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and oxygen radical absorbance capacity (ORAC) assays, chromatographic analysis of organic acids and sugars, color measurement, techno-functional characterization, and vibrational spectroscopy including Fourier Transform infrared with attenuated total reflectance (FT-IR/ATR) and Raman were employed. The crude protein content was 16.13 ± 0.43%. Moringa leaves contained all essential amino acids, with notably high tryptophan content (amino acid score, AAS = 200.00%). The amino acids limiting the nutritional value of the protein were primarily sulfur-containing amino acids (AAS = 49.57%) and lysine (AAS = 49.79%). Histidine, leucine, and valine also showed levels below the reference protein. Antioxidant activity exhibited solvent-dependent patterns: the 80% ethanolic extract demonstrated significantly higher FRAP activity (27.05 ± 1.05 mg Trolox Equivalent (TxE)/g dry matter (DM)) and ORAC values (107.24 ± 6.80 mg TxE/g DM), while no statistically significant differences between extracts were observed for DPPH, ABTS, or total phenolic content. Chromatographic profiling identified fructose and glucose as the predominant sugars, alongside citric, succinic, lactic, and acetic acids. The leaves exhibited favorable techno-functional properties, including high water holding capacity and water solubility index. Spectroscopic analysis revealed bands consistent with proteins, lipids, carbohydrates, and glycoside-related structures, while the preserved green-yellow coloration (hue angle 101.68°) indicated retention of pigment-related features during processing. These findings provide compositional and physicochemical characteristics of Moringa leaves relevant to their evaluation as a plant-derived food material. Full article

In the present work, a novel series of eleven sulfonate derivatives with potent inhibitory activity against butyrylcholinesterase (BChE) is reported. Of these, compounds 2-[(E)-(2-Benzoylhydrazinylidene)methyl]phenyl 5-(dimethylamino)naphthalene-1-sulfonate (5c, IC₅₀ = 1.11 µM) and tert-butyl (2E)-2-[(2-{[5-(dimethylamino)naphthalene-1-sulfonyl]oxy}phenyl)methylidene]hydrazine-1-carboxylate (5b, IC₅₀ = 11.51 µM) exhibit stronger inhibitory activity than rivastigmine, the reference compound, and exhibit high selectivity for BChE over AChE (e.g., selectivity index 57 for 5c). Interestingly, compound 5c also exhibited anti-inflammatory effects, which is important for potential therapeutic applications, especially in Alzheimer’s disease. These new compounds were designed through a structure-based approach using molecular modeling techniques (docking, molecular dynamic (MD) simulations, and QTAIM (quantum theory of atoms in molecules) calculations). The most promising compounds show no detectable toxic effects and satisfy Lipinski’s rule of five, indicating that they represent attractive starting structures for the design of new derivatives acting as specific BChE inhibitors. In addition, our results indicate that relatively simple computational techniques such as docking calculations and toxicity prediction programs can be valuable when properly used in the search of new candidates for this particular target. Docking calculations show that the more active compounds of this series reach the bottom region of the gorge interacting with residues within the active site of BChE. However, our data further suggest that the use of more precise techniques, such as MD simulations and QTAIM analysis, is necessary to obtain detailed insight into ligand–enzyme interactions. Regarding QTAIM calculations, they demonstrate that such computations are very useful to evaluate the molecular interactions of the different molecular complexes. In summary, we report a new series of sulfonate derivatives as promising starting structures for the development of new selective BChE inhibitors. Full article

The present paper investigates the adsorption performance of pinewood-derived biochars produced at two pyrolysis temperatures (850 °C, PW-A; 1000 °C, PW-B), including sieved fractions (PW-A1 and PW-A2) and a functionalized variant (PW-C), for the removal of five short- and intermediate-chain PFASs (PFBA, PFBS, PFHxA, PFHxS, and GenX) from water under continuous-flow conditions. Adsorption behavior was evaluated using Freundlich and Hill isotherm models. The Hill model provided a superior fit for most PFAS–adsorbent systems, highlighting the importance of cooperativity effects, particularly for short-chain PFASs. In single-compound experiments, PFBS and GenX showed the highest adsorption capacities (up to 82.3 and 68.5 mg g⁻¹), while PFBA and PFHxA exhibited the lowest. Among the tested materials, biochar produced at 1000 °C (PW-B) consistently demonstrated the highest adsorption efficiency. Compared to activated carbon, PW-B showed comparable performance for PFBA, PFBS, PFHxA and PFHxS and significantly better performance for GenX. In mixed-PFAS systems, competitive effects reduced adsorption capacity and cooperativity. Sulfonic PFASs showed higher affinity than carboxylic PFASs, following the trend PFHxS > PFBS > PFHxA > PFBA. Overall, the results demonstrate that waste-derived biochar represents a low-cost and sustainable alternative for PFAS removal in realistic water-treatment scenarios, supporting scalable solutions aligned with global environmental goals. Full article

Kinmen peanut (Arachis hypogaea L. cultivar Kinmen No. 1) is a unique crop used to produce local specialty “peanut candy”; however, the peanut skins (PSs) are treated as waste owing to the bitter taste. To support the valorization of this agro-industrial by-product, peanut skin ethanolic extract (PSE) was prepared and evaluated for its hypolipidemic potential in a cholesterol/fat-fed hamster model, together with its antioxidant capacity and chemical composition. Hamsters were fed a cholesterol/fat-enriched diet supplemented with PSE at 0.1%, 0.2%, or 0.4% (w/w) for 8 weeks. Serum lipid profiles were determined, and derived atherogenic indices were calculated. In parallel, antioxidant activity was assessed using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and reducing power assays, while chemical characterization included total phenolics, crude phytosterols, and HPLC profiling of representative phenolic compounds. PSE significantly reduced serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) compared with the cholesterol/fat-enriched control, whereas triglycerides were not significantly altered. The LDL-C/HDL-C ratio was also reduced in PSE-treated groups, with the greatest reduction observed in the 0.1% PSE group (0.33 ± 0.04 vs. 0.56 ± 0.12 in the negative control). In addition, PSE exhibited marked antioxidant activity, with IC₅₀ values of 141.3 and 76.2 μg/mL in the DPPH and ABTS assays, respectively. Chemical analyses showed that PS contained 1098 ± 189 µg β-sitosterol equivalents/g PS and 199.3 ± 4.6 mg gallic acid equivalent (GAE)/g PS, and HPLC identified p-coumaric acid, ferulic acid, gallic acid, chlorogenic acid, daidzein, catechin, and resveratrol as representative phenolic constituents. Collectively, these findings support Kinmen peanut skin as a promising value-added source of bioactives for functional ingredient development targeting cholesterol dysregulation and oxidative processes. Full article

Background/Objectives: Achieving effective hemostasis is a vital step in wound healing, particularly in cases of severe bleeding caused by surgical procedures or trauma. This study focuses on the development of chitosan-based dressings enriched with Heparin (hep)-loaded poly(butylene succinate) (PBSu) nanoparticles to combine hemostatic and anticoagulant properties. Methods: Chitosan, a biocompatible and biodegradable carbohydrate with inherent antibacterial and hemostatic properties, was chemically modified with 2-(N-morpholino)ethanesulfonic acid (MES) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) to enhance its swelling ability and hemostatic activity. PBSu nanoparticles were synthesized using an oil-in-water emulsification method and loaded with Hep to achieve controlled anticoagulant release. The dressings of the modified chitosan derivatives with the nanoparticles which were systematically characterized for morphology, chemical structure, swelling ability, loading capacity, and Hep release kinetics. Results: This dual-function system is designed to decouple local surface hemostasis from thrombotic processes: the chitosan matrix provides rapid topical hemostasis, while controlled heparin release from the nanoparticles aims to modulate excessive fibrin deposition, support microvascular perfusion, and exploit the pro-healing benefits of low-dose heparin reported in advanced wound dressings, particularly in high-risk or thrombotic-prone patients. In vitro and in vivo studies demonstrated their potential for promoting rapid hemostasis. Conclusions: These findings suggest that the integration of modified chitosan and Hep-loaded nanoparticles is a promising strategy for advancing wound care and hemostatic technologies. Full article

Dual-fuel combustion is often proposed for diesel engines as a means to partially replace conventional diesel with cleaner and/or more sustainable alternatives, such as those derived from green hydrogen. However, the low reactivity of these fuels (i.e., methane, hydrogen, and ammonia) often leads to prolonged ignition delay (ID) and combustion instability. This challenge could potentially be overcome using nanomaterials, which are additives that could improve reactivity and compensate for autoignition deficiencies. Thus, this study evaluates the effect of carbon nanotubes (CNTs) dispersed in diesel fuel on the autoignition process under dual-fuel operation. CNTs were dispersed at a concentration of 100 mg/L and stabilized with surfactant sodium dodecylbenzene sulfonate (SDBS). The resulting nanofuels were then tested in a constant volume combustion chamber (CVCC) using methane, hydrogen, and ammonia as secondary fuels across various energy substitution ratios and temperatures (535 °C, 590 °C and 650 °C). The results show that the impact of CNTs on ID is negligible, especially at high temperatures. At the lowest tested temperature (535 °C) and 40% methane substitution ratio, only slight reductions in ID were obtained. Nevertheless, this effect is less significant at higher temperatures (590 °C and 650 °C). Regarding pressure gradient, the addition of CNTs and SDBS generally induced a decrease in pressure-peak of up to 15%. This trend is attributed to the trapping of fuel droplets within the CNT structures, which creates a physical barrier that delays vaporization. Results confirm that autoignition, which is expected to be the main phenomenon influenced by CNT addition, is not enhanced. Full article

This study evaluated the antimicrobial and antioxidant activities and chemical properties of four wild edible macrofungi—Tuber aestivum (Wulfen) Spreng., Terfezia claveryi Chatin, Agaricus arvensis Schaeff. and Bovistella utriformis (Bull.) Demoulin & Rebriev—collected from different regions of Türkiye, with particular emphasis on the role of phenolic compounds. Methanol and hexane extracts were assessed for antimicrobial activity against Gram-positive, Gram-negative, multidrug-resistant (MDR) bacterial strains, and Candida albicans using minimum inhibitory concentration (MIC) assays. Total phenolic content (TPC) was determined, and antioxidant capacities were evaluated using DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)), FRAP (ferric reducing antioxidant power), and CUPRAC (cupric ion reducing antioxidant capacity) assays. The chemical profiles of hexane extracts were characterized by GC–MS analysis, whereas methanol extracts were analyzed by LC–MS/MS. Methanol extracts with high content of phenolic compounds exhibited markedly higher antimicrobial activity than hexane extracts, especially against Gram-positive bacteria. B. utriformis and A. arvensis displayed the highest phenolic contents (29.61 ± 0.6 and 27.14 ± 0.59 mg GAE/g DW, respectively) and antioxidant activities, revealing a strong positive correlation between TPC and antioxidant capacity. LC–MS/MS analysis revealed catechin, cinnamic acid, and caffeic acid as prominent phenolic constituents, highlighting the role of polyphenols in the observed bioactivity. GC–MS profiling predominantly identified fatty acid methyl esters, particularly linoleic and oleic acids, together with minor phenolic derivatives, suggesting a possible synergistic interaction contributing to the overall biological potential. The results highlight phenolic-rich macrofungi as valuable natural sources of antioxidant and antimicrobial agents with potential applications. Full article

Oxidative stress plays a central role in the development of chronic degenerative diseases, prompting growing interest in natural antioxidants, particularly phenolic compounds from early developmental plant tissues. This study investigated the chemical composition and antioxidant capacity of Acer tegmentosum sprouts at the cotyledon expansion stage using integrated metabolite profiling and targeted quantification approaches. A. tegmentosum sprout extracts (ASE) were characterized by liquid chromatography–tandem mass spectrometry (LC–MS/MS) for untargeted metabolite annotation and by high-performance liquid chromatography (HPLC) for the targeted quantification of selected phenolic acids and coumarins using authentic standards. Antioxidant activity was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays. LC–MS/MS analysis identified twelve phenolic compounds, including gallic acid, protocatechuic acid, scopoletin, and their derivatives. HPLC results confirmed gallic acid (5.54 mg/g extract) as the predominant phenolic constituent, and the overall composition indicated a phenolic acid-enriched profile. ASE showed notable DPPH and ABTS radical scavenging activities, with IC₅₀ values of 376.40 and 311.00 μg/mL, respectively, although these activities were lower than those of ascorbic acid. Overall, these findings define the baseline chemical and antioxidant properties of ASE and identify analytically traceable marker compounds for standardization and functional material development. Further studies across different developmental stages and cultivation conditions are needed to verify generalizability and refine marker selection for quality control purposes. Full article

Sweet potato (Ipomoea batatas L.) is cultivated globally and generates a large quantity of plant-derived residues, including leaves, stems, and non-commercial cull roots, which remain insufficiently utilized despite their potential functional value. Although the antioxidant properties of sweet potato leaves have been reported, comparative investigations of different plant parts evaluated under the same experimental conditions, particularly in relation to skin-associated biological functions, are still limited. In this study, aqueous extracts prepared from sweet potato leaves, stems, and cull roots were obtained using a food-grade extraction process suitable for practical application. The phenolic composition and biological properties of the extracts were comparatively analyzed. Antioxidant capacity was examined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay, ferric reducing antioxidant power (FRAP), as well as assays associated with superoxide dismutase (SOD)-like and catalase-related activities. Skin-related biological responses were further evaluated by measuring elastase and collagenase inhibition, type I procollagen synthesis, and matrix metalloproteinase-1 (MMP-1) secretion in CCD-986Sk human dermal fibroblasts. Among the tested samples, the leaf-derived aqueous extract exhibited a higher total phenolic content, greater accumulation of chlorogenic acid, and stronger antioxidant responses compared with stem and cull root extracts. In addition, the leaf extract showed more pronounced effects on collagen metabolism, including enhanced procollagen synthesis and reduced MMP-1 secretion, while maintaining acceptable cell viability within the tested concentration range. Overall, these results demonstrate clear tissue-dependent functional differences among sweet potato residues and indicate that leaf-derived extracts represent a promising functional material for skin-related and cosmetic applications. Full article

The oxidative stability of meat products is a crucial factor determining quality, shelf life, and consumer acceptance, as lipid and protein oxidation promote undesirable changes in sensory attributes and nutritional content. Antioxidant capacity (AOC) assays such as total phenolic content (TPC), ferric reducing antioxidant power (FRAP), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^•+), and 2,2-diphenyl-1-picrylhydrazyl (DPPH^•) are commonly applied in meat systems to assess the AOC associated with both intrinsic muscle components (endogenous) and the protective effects of natural ingredients (exogenous added compounds), i.e., antioxidants. Although differences in analytical methodologies limit direct comparisons among studies, it has been demonstrated that meat products inherently contain compounds that modulate oxidative reactions, with their effectiveness influenced by meat type, processing, and storage conditions. Within this framework, natural ingredients, including plant- and fungal-derived ingredients and their by-products, have gained attention as sources of natural antioxidants, whose capacity depends on the extraction method, the solvent used, and their behavior during gastrointestinal digestion, as evaluated using simulated gastrointestinal digestion (sGD) models. Numerous studies have shown that incorporating natural extracts or powders into meat products enhances AOC during refrigerated storage, with the effect generally depending on the concentration used. Moreover, several natural antioxidant treatments maintain or even enhance their AOC when assessed under sGD conditions. Full article