Search Results (104)

Resveratrol is one of the most extensively studied natural products due to its pleiotropic health benefits. However, its low water solubility and limited stability hinder its application in the nutraceutical, cosmetic, and pharmaceutical sectors. In this work, we investigated the ability of a cationic mono-choline-β-cyclodextrin derivative to complex trans-resveratrol. The complex was prepared using a phase solubility method without using organic solvents and was found to be stable after freeze-drying. The complex was characterized by a phase solubility study, NMR spectroscopy, and molecular modeling simulations, which revealed a 1:1 stoichiometry, a stability constant of 2051 M⁻¹ (K_C), and structural details. Complexation improved resveratrol’s solubility and dissolution rate, reduced its photoinduced trans-to-cis isomerization, and preserved its radical scavenging activity. The wound-healing activity of the complex was demonstrated via in vitro experiments on human keratinocyte cells. Full article

The aim of this work was to extract phenolic compounds (PCs) from Cistus ladanifer L. post-distillation residues using two different methods (solid–liquid extraction (SLE) and subcritical water extraction (SWE)) and to compare the extracts’ total phenolic content (TPC) and antioxidant activity (AA) by 1,1-diphenyl-2-picrylhydrazyl radical (DPPH^•) and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS^•+) scavenging activities, as well as by the ferric-reducing antioxidant power (FRAP) assay. SWE extraction displayed a higher TPC value (increased from 146.53 ± 11.68 to 276.37 ± 20.59 mg gallic acid equivalents (GAEs)/g extract dry weight (dw)) and higher AA in the DPPH^• (increased from 334.27 ± 36.06 to 532.17 ± 66.38 mg Trolox equivalents (TEs)/g extract dw), ABTS^•+ (increased from 438.07 ± 77.22 to 594.08 ± 33.57 mg TEs/g extract dw), and FRAP (increased from 10.91 ± 2.03 to 170.26 ± 25.36 mg ascorbic acid equivalents (AAEs)/g extract dw) assays. These results demonstrate the importance of the extraction method in PC extraction and the antioxidant power of the extracts produced. These results provide critical insights into the potential application of C. ladanifer post-distillation residues and the production of polyphenol rich extracts that might be useful in the food, cosmetic, and pharmaceutical sectors. Full article

Acesulfame potassium (ACE) is an emerging pollutant with the potential to induce a range of health hazards. In this study, waste natural pyrite (with some oxides on its surface) was washed and used as an activator to activate potassium peroxomonosulfate (PMS) to degrade ACE in water. The experimental results demonstrate that waste natural pyrite with an oxidized layer exhibited a significant degradation effect on ACE. Under conditions of 0.7 g/L pyrite and 60 μM PMS, a degradation rate of 99.3% for ACE was achieved within 15 min, and the mineralization rate reached 15.3% within 30 min. In addition, concerning its applicability, waste natural pyrite demonstrates strong activation ability within a pH range of 3 to 7. It is important to note that while HCO₃⁻ and Ca²⁺ can influence the effectiveness, other common anions and cations do not significantly affect the degradation process. Mechanistic studies reveal that the primary active species in the waste natural pyrite/PMS system were sulfate radicals (SO₄^•−) as well as hydroxyl radicals (^•OH), which contributed 50.6% and 36.9%, respectively. In addition, the analysis of ACE degradation products indicates that no highly toxic intermediates were generated during the degradation process. Overall, this study underscores the outstanding performance of waste natural pyrite as an activator, providing a safe, efficient, and cost-effective approach for degrading organic pollutants like ACE. Full article

Colonization of surfaces by bacteria followed by biofilm formation is a cause of wound infections associated with the use of medical devices as stents, catheters, implants, etc. For prevention of such infections, the preparation of surfaces with antifouling, anti-adhesive and antibacterial properties is of great interest. In this context, four zwitterionic (styrenic or methacrylic) monomers bearing a pyridinium, imidazolium or ammonium cationic group linked to a sulfonate anionic group were chosen and polymerized on ceramic for implant technology. Zwitterionic polymers were successfully grafted onto zirconia pellets through surface-initiated radical polymerization with blue-light photoactivation (“grafting from”). Wettability measurements showed the formation of hydrophilic surfaces with water contact angles in the range of 35–40°. Detailed X-ray photoelectron spectroscopy analysis revealed a surface where the zirconia pellets exhibited zwitterionic polymer brushes with high coverage. The core-level spectra of C1s, N1s and S2p were separated into many components, allowing their attribution to the different atoms in the monomer unit and confirming that zwitterionic polymers were successfully grafted from zirconia surfaces. Full article

Phosphorus contamination in water bodies is a major contributor to eutrophication, leading to algal overgrowth, oxygen depletion, and ecological imbalance. Conventional treatment methods, including chemical precipitation and synthetic adsorbents, are often limited by high operational costs, low biodegradability, and secondary pollutant generation. In this study, a cationic starch was synthesized through free radical graft polymerization of 3-methacrylamoylaminopropyl trimethyl ammonium chloride (MAPTAC) onto corn starch. The modified polymer exhibited a high degree of substitution (DS = 1.24), indicating successful functionalization with quaternary ammonium groups. Theoretical calculations using zDensity Functional Theory (DFT) at the B3LYP/6-311+G(d,p) level revealed a decrease in chemical hardness (from 0.10442 eV to 0.04386 eV) and a lower ionization potential (from 0.24911 eV to 0.15611 eV) in the modified starch, indicating enhanced electronic reactivity. HOMO-LUMO analysis and molecular electrostatic potential (MEP) maps confirmed increased electron-accepting capacity and the formation of new electrophilic sites. Experimentally, the cationic starch showed stable zeta potential values averaging +15.3 mV across pH 5.0–10.0, outperforming aluminum sulfate (Alum), which reversed its charge above pH 7.5. In coagulation-flocculation trials, the modified starch achieved 87% total suspended solids (TSS) removal at a low coagulant-to-biomass ratio of 0.0601 (w/w) using Scenedesmus obliquus, and 78% TSS removal in real wastewater at a 1.5:1 ratio. Additionally, it removed 30% of total phosphorus (TP) under environmentally benign conditions, comparable to Alum but with lower chemical input. The integration of computational and experimental approaches demonstrates that MAPTAC-modified starch is an efficient, eco-friendly, and low-cost alternative for nutrient and solids removal in wastewater treatment. Full article

Superoxide dismutase 1 (SOD1) is a crucial enzyme that protects cells from oxidative damage by converting superoxide radicals into H₂O₂ and O₂. This detoxification process, essential for cellular homeostasis, relies on a precisely orchestrated catalytic mechanism involving the copper cation, while the zinc cation contributes to the structural integrity of the enzyme. This study presents the 2.3 Å crystal structure of human SOD1 (PDB ID: 9IYK), revealing an assembly of six homodimers and twelve distinct active sites. The water molecules form a complex hydrogen-bonding network that drives proton transfer and sustains active site dynamics. Our structure also uncovers subtle conformational changes that highlight the intrinsic flexibility of SOD1, which is essential for its function. Additionally, we observe how these dynamic structural features may be linked to pathological mutations associated with amyotrophic lateral sclerosis (ALS). By advancing our understanding of hSOD1’s mechanistic intricacies and the influence of water coordination, this study offers valuable insights for developing therapeutic strategies targeting ALS. Our structure’s unique conformations and active site interactions illuminate new facets of hSOD1 function, underscoring the critical role of structural dynamics in enzyme catalysis. Moreover, we conducted a molecular docking analysis using SOD1 for potential radical scavengers and Abelson non-receptor tyrosine kinase (c-Abl, Abl1) inhibitors targeting misfolded SOD1 aggregation along with oxidative stress and apoptosis, respectively. The results showed that CHEMBL1075867, a free radical scavenger derivative, showed the most promising docking results and interactions at the binding site of hSOD1, highlighting its promising role for further studies against SOD1-mediated ALS. Full article

As an alternative to bisphenol A, bisphenol S (BPS) is considered an emerging concern. In this study, the degradation of BPS by persulfate (PS), ultraviolet (UV), and UV/PS was comprehensively examined in ultra-pure and saline waters. UV/PS effectively degraded BPS, and the observed first-order rate constant, k_obs, increased from 0.021 to 0.382 min⁻¹ with an increasing PS concentration from 100 to 1000 μΜ. The addition of humic acid (HA) inhibited the degradation of BPS, and 1/k_obs was directly proportional to the concentration of HA. In salty water containing 540 mM Cl⁻ or 0.8 mM Br⁻, UV/PS possessed a higher degradation ability for BPS: the corresponding k_obs values were 1.45 and 1.66 times that of the control sample, respectively. Eighteen degradation products, including β-scission, sulfate addition, quinone type, ring-opening, and cross-coupling, were identified using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Two possible pathways were proposed: (i) the initial step was considered to be an electron transfer reaction from BPS to SO₄^•−, leading to the formation of a phenyl radical cation R1, and then phenol radical R4, 4-hydroxybenzenesulfonate cation R5, phenoxyl radical R3, resonant-type carbon-centered radical R2, and their secondary products; (ii) another pathway was the sulfate addition and hydroxylation. These primary reaction sites were further verified by theoretical calculation. This study highlights the effectiveness of UV/PS as a promising strategy for the remediation of BPS and other endocrine-disrupting chemicals in ultra-pure and saline waters (540 mM NaCl or/and 0.8 mM NaBr). Full article

The aim of this work was to extract phenolic compounds (PCs) from spent coffee grounds (SCGs) using two different methods (solid-liquid extraction (SLE) and subcritical water extraction (SWE)) and compare their total phenolic content (TPC) and their antioxidant activity (AA) by 1,1-diphenyl-2 picrylhydrazyl radical (DPPH^•), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS^•+) scavenging activities, and ferric reducing antioxidant power (FRAP) assay. The SWE extracts displayed higher TPC values and higher scavenging activity in the DPPH^• and ABTS^•+ assays. The SLE extracts displayed a higher ferric reducing power. These results highlight the impact of the extraction method in PCs extraction and the antioxidant power of the extracts produced. Full article

Polymeric hydrogel materials have excellent electrical conductivity and mechanical properties and will be potentially used in wearable electronic devices, soft robotics, and medical treatment. In this paper, a PAA-Fe³⁺-IL ionohydrogel (poly(acrylic acid)-Fe³⁺-ionic liquid ionohydrogel) with excellent mechanical and conductive properties is prepared by simple free radical polymerization. The presence of metal-ligand crosslinking within the ionohydrogel improves the mechanical properties of the hydrogel. When the IL content is 10 wt%, it has the maximum tensile strength and strain. When the ferric ion concentration is 0.3 mol%, the maximum tensile strength is 495.09 kPa. When the ferric ion concentration is 0.1 mol%, the maximum strain is 1151.35%. The tensile behavior of the ionohydrogels is quantitatively analyzed by the viscoelastic model. In addition, free metal ions and anions and cations in IL endowed the hydrogel with a conductivity of 1.48 S/m and a strain sensitivity of 8.04. Thus, the PAA-Fe³⁺-IL ionohydrogel can be successfully used as a humidity sensor due to the hydrophilic ionic liquid, which can increase the conductivity of the hydrogel by absorbing water. The physical crosslinking density inside the hydrogel is much higher than the chemical crosslinking density, which causes hydrogel dissolution in deionized water by swelling and is conducive to the recycling of the hydrogel. This is a promising material for use in intelligent wearable electronics and as a humidity sensor. Full article

Background/Objectives: Perilla frutescens has historically been used to protect against inflammation and redox stress. This has been partly attributed to its high polyphenolic content; however, polyphenolic components in Perilla extract remain incompletely defined. This study aimed to characterise the polyphenolic composition in Perilla extract and evaluate its effect on the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2), regulating antioxidant defenses during inflammation and oxidative stress. Methods: Hot water extraction from Perilla leaves was followed by fractionation using four solvents of different polarity, namely methanol, butanol, ethyl acetate and ether. The polyphenolic composition of these fractions was analysed using RP-HPLC, and some of these compounds were quantified. The total phenolic, flavonoid, and ortho-diphenolic contents of each Perilla fraction were determined. The antioxidant activity was assessed using metal cation reduction and radical scavenging assays. A dual-luciferase assay using a human NQO1 ARE-luciferase reporter plasmid was employed to quantify Nrf2 activation by the Perilla fractions. Results: HPLC analysis identified 35 polyphenolic compounds, with the highest phenolic content present in the polar fractions and rosmarinic acid being the major constituent. Radical scavenging tests (DPPH and ABTS) confirmed the highest antioxidant capacity in the polar fractions. On cells in vitro, the methanol Perilla fraction displayed the strongest antioxidant activity, showing up to a 1.5-fold increase in human NQO1 ARE-luciferase reporter induction. Conclusions: This study has shown that Perilla extract contains a diversity of polyphenolic compounds contributing to its potent antioxidant effects, with methanol and butanol being the most efficient extraction solvents. While rosmarinic acid is expected to be the major contributor towards providing protection against inflammation and redox stress, further work is required on the synergystic effects between different polyphenols. Full article

The addition of an extract to an emulsion is intended to improve its fragrance and care qualities. Green tea is a beverage known all over the world. It is tasty and has beneficial effects on human health due to its high polyphenol content. The compounds present in this variety of tea have also made it an interesting cosmetic ingredient. The polyphenols contained in green tea have antioxidant properties and can delay the ageing process in human skin. Various preparations with this ingredient can be found on the market—from creams to hair care products. Making one’s own cosmetics is also a trend. In the following study, three creams containing green tea extracts from three different manufacturers were prepared, and the total polyphenol (TP) contents, the phenolic profile of the extracts used and the antioxidant activity of these preparations were examined using two methods: DPPH^• and ABTS^•+ cationic radicals. The study showed that the antioxidant activity of the glycerin–water extracts measured by the selected methods was higher than that of the oil extract. Among the creams, the product with green tea extract from Firm 2 (glycerin–water extract) showed the best antioxidant properties. Full article

In response to the significant waste of bioresources from passion fruit peels in the current market, aiming to enhance the economic benefits of soluble dietary fiber (SDF) derived from passion fruit peels in the food industry, this study extracted the SDF from passion fruit peels using six different methods and assessed how these methods affected its physicochemical properties. The results indicated that the acid-assisted extraction method (AAE-1) was the most effective at protein removal among the six methods, and the SDF derived from this method had the highest extraction yield (17.05%), cation exchange capacity (1.17 mL/g), total monosaccharide content (92.6620 µg/mg), xylose (3.2187 µg/mg), and mannose (3.7334 µg/mg). The SDF extracted by enzyme-assisted extraction method (EAE) showed the highest DPPH free radical scavenging capacity (66.67%), reducing sugar content (5.71%), oil-holding capacity (5.86 g/g), and glucose content (55.9662 µg/mg). The SDF extracted by alkali-assisted extraction method (AAE-2) provided the highest water-holding capacity (7.82 g/g), solubility (4.24 mL/g), and rhamnose content (3.0854 µg/mg). The SDF extracted by microwave-assisted extraction method (MAE) possessed the highest total sugar content (20.15%), ABTS radical scavenging capacity (65.46%), ferric ion-reducing capacity (58.83%), and galactose content (7.8912 µg/mg). The SDF extracted by hot water-assisted extraction method (HWE) of soluble fiber from passion fruit peels had the highest arabinose content (5.3775 µg/mg) and galacturonic acid content (35.6795 µg/mg), as well as the highest weight-average molecular weight (Mw) and number-average molecular weight (Mn). These findings provide a theoretical foundation for the development and utilization of passion fruit peels. Full article

The pyridinium phenolate punicine is a switchable molecule from Punica granatum. Depending on the pH, punicine exists as a cation, neutral molecule, anion, or dianion. In addition, punicine reacts to light, under the influence of which it forms radical species. We report on three punicine derivatives that possess an adamantyl, 2-methylnonyl, or heptadecyl substituent and on their performance in the flotation of lithium aluminate, an engineered artificial mineral (EnAM) for the recycling of lithium, e.g., from lithium-ion batteries. By optimizing the parameters: pH and light conditions (daylight, darkness), recovery rates of 92% of LiAlO₂ are achieved. In all cases, the flotation of the gangue material gehlenite (Ca₂Al[AlSiO₇]) is suppressed. IR, the contact angle, zeta potential measurements, TG-MS, and PXRD confirm that the punicines interact with the surface of LiAlO₂, which is covered by LiAl₂(OH)₇ after contact to water, resulting in a hydrophobization of the particle. The plasma pretreatment of the lithium aluminate has a significant influence on the flotation results and increases the recovery rates of lithium aluminate in blank tests by 58%. The oxidative plasma leads to a partial dehydratisation of the LiAl₂(OH)₇ and thus to a hydrophobization of the particles, while a reductive plasma causes a more hydrophilic particle surface. Full article

Near-infrared light-triggered photocatalytic water treatment has attracted significant attention in recent years. In this novel research, rational sonochemical fabrication of Ag₂S/g-C₃N₄ nanocomposites with various compositions of Ag₂S (0–25) wt% was carried out to eliminate hazardous rhodamine B dye in a cationic organic pollutant model. g-C₃N₄ sheets were synthesized via controlled thermal annealing of microcrystalline urea. However, black Ag₂S nanoparticles were synthesized through a precipitation-assisted sonochemical route. The chemical interactions between various compositions of Ag₂S and g-C₃N₄ were carried out in an ultrasonic bath with a power of 300 W. XRD, PL, DRS, SEM, HRTEM, mapping, BET, and SAED analysis were used to estimate the crystalline, optical, nanostructure, and textural properties of the solid specimens. The coexistence of the diffraction peaks of g-C₃N₄ and Ag₂S implied the successful production of Ag₂S/g-C₃N₄ heterojunctions. The band gap energy of g-C₃N₄ was exceptionally reduced from 2.81 to 1.5 eV with the introduction of 25 wt% of Ag₂S nanoparticles, implying the strong absorbability of the nanocomposites to natural solar radiation. The PL signal intensity of Ag₂S/g-C₃N₄ was reduced by 40% compared with pristine g-C₃N₄, implying that Ag₂S enhanced the electron–hole transportation and separation. The rate of the photocatalytic degradation of rhodamine B molecules was gradually increased with the introduction of Ag₂S on the g-C₃N₄ surface and reached a maximum for nanocomposites containing 25 wt% Ag₂S. The radical trapping experiments demonstrated the principal importance of reactive oxygen species and hot holes in destroying rhodamine B under natural solar radiation. The charge transportation between Ag₂S and g-C₃N₄ semiconductors proceeded through the type I straddling scheme. The enriched photocatalytic activity of Ag₂S/g-C₃N₄ nanocomposites resulted from an exceptional reduction in band gap energy and controlling the electron–hole separation rate with the introduction of Ag₂S as an efficient photothermal photocatalyst. The novel as-synthesized nanocomposites are considered a promising photocatalyst for destroying various types of organic pollutants under low-cost sunlight radiation. Full article

The objective of this study was to analyze the response of antioxidant parameters in soybean plants inoculated with newly isolated Bradyrhizobium japonicum and Bacillus subtilis strains as single and co-inoculants under drought stress. Bacterial strains were selected according to osmotic stress tolerance (in the presence of 36% PEG 6000) in appropriate liquid media. The effect of soybean inoculation was examined in a soil pot experiment in water deficit conditions (0 and 7 days withholding water). The influence of water stress and inoculation was evaluated in soybean leaves, roots, and nodules through guaiacol peroxidase (POX), ionically cell-wall-bound peroxidase (POD) activity, and ABTS˙⁺ radical cation scavenging capacity, as well as parameters of N-fixation efficiency. The results showed a significant influence of inoculation on constitutive and drought-induced antioxidant and N-fixation parameters. Inoculation increased the activity of POX (up to 116, 169, and 245%), POD (up to 116, 102, and 159%), and antioxidant capacity (up to 74, 76, and 81%) in soybean leaves, roots, and nodules under water deficit, respectively. Application of bacterial strains resulted in higher shoot, root, and nodule weight and nitrogen content both in non-stressed and drought stress conditions. Overall, co-inoculation had better effects on the investigated soybean parameters compared to single inoculation. Selection and application of bacterial strains with improved tolerance to drought stress is necessary in developing inoculants that would result in enhanced crop production under unfavorable environmental conditions. Full article