Search Results (562)

Purple corn is an anthocyanidin-rich plant, with anthocyanidins being particularly abundant in the waste it produces. This study explored the variation in anthocyanidins in each part of the plant during the growth period of a novel type of purple corn (Zea mays L., cv Jizi-01). The results showed that vacuum freeze-drying had advantages over cabinet drying in protecting anthocyanidins, except in the cornsilk part. The anthocyanidin contents of the different plant parts varied with time. Purple corn cob anthocyanidins (PCCAs) were isolated and identified owing to their abundance (14.95 g/kg, dry basis (DB)) among all plant parts. PCCA comprises three anthocyanidins, namely cyanidin, pelargonidin and peonidin, forming 11 types of anthocyanins when combined with glycosidic bonds. Finally, the in vitro scavenging effects of PCCA on DPPH, ABTS·⁺ and ·OH radicals were evaluated, and the scavenging rates reached up to 89.92%, 96.95% and 90.76%. This study shows that purple corn (Zm Jizi-01) is a novel resource rich in anthocyanidins, with high economic potential. Full article

In this work, we aim to enhance the photocatalytic performance of SrTiO₃ by constructing a heterojunction with photoactive BiOBr. The novelty of this study lies in demonstrating the dual functionality of the SrTiO₃/BiOBr heterojunction in both photocatalytic tetracycline degradation and antibacterial applications and correlating its performance with its interfacial electronic properties. A SrTiO₃/BiOBr (50STO) heterojunction was successfully synthesized by combining microwave-assisted sol–gel-derived SrTiO₃ with co-precipitated BiOBr via solid-state calcination. XRD analysis revealed that the synthesized composite consisted of crystalline cubic SrTiO₃ and tetragonal BiOBr, confirming the successful formation of a 50STO heterojunction while preserving the crystal structures of both components. PL and EIS analyses revealed modified charge-carrier behavior, further supporting the successful formation of the 50STO heterojunction. XPS confirmed the chemical states of the constituent elements and revealed changes in the surface chemical environment following the coupling of SrTiO₃ with BiOBr. SEM, elemental mapping, and UV–Vis DRS analyses demonstrated uniform elemental distribution, enhanced visible-light absorption, suppressed electron–hole recombination, and improved interfacial charge transfer. Consequently, the optimized 50STO composite achieved 45% tetracycline degradation under visible-light irradiation within 150 min, whereas pristine SrTiO₃ degraded only 2%. The apparent reaction rate constant increased from 6.11 × 10⁻⁷ to 3.2 × 10⁻³ min⁻¹, while the heterojunction remained stable over five reuse cycles. Radical scavenging and LC–MS analyses identified h⁺ and •OH as the dominant reactive species and revealed successive tetracycline degradation. The composite also exhibited excellent antibacterial activity against E. coli under white-light irradiation. Full article

Background: Carbamazepine (CBZ) and aripiprazole (ARI), frequently detected in medical facility effluents, are resistant to conventional wastewater treatment. However, a systematic comparison of their electrolytic degradation product profiles under different electrode conditions using an identical operating platform has not been previously reported. Methods: CBZ and ARI in NaCl solutions were subjected to electrolytic oxidation using the Eleca^® system with either a boron-doped diamond (BDD) or a metal electrode. Residual drugs were quantified by LC-MS/MS and pseudo-first-order degradation kinetics were calculated. Transformation products were characterized by LC/PDA/HRMS/MS based on accurate mass measurements, MS/MS fragmentation, chromatographic behavior, and UV absorption. Radical scavenger experiments using methanol and tert-butanol were conducted to investigate reactive species’ contributions to degradation. Results: Both drugs were rapidly degraded under all conditions, with the metal electrode consistently exhibiting higher apparent pseudo-first-order rate constants than the BDD electrode. The metal electrode generated hydrophobic intermediates apparently retaining aromatic skeletons (consistent with partial oxidation), whereas the BDD electrode yielded more polar, low-molecular-weight products consistent with more extensive skeletal fragmentation (deep oxidation). Scavenger experiments suggested a greater relative contribution of hydroxyl radicals (•OH) under BDD electrode conditions. Transformation products were transiently detected but eliminated by prolonged electrolysis. Conclusions: Electrode material critically determines the degradation pathway, reactive species distribution, and product profile. Structural analysis of the tentatively identified transformation products suggests loss of pharmacophore integrity in several intermediates; however, residual pharmacological risk has not been experimentally validated and requires biological sassays for confirmation. Furthermore, the observed disappearance of the parent compounds does not demonstrate complete mineralization, detoxification, or environmental safety, as total organic carbon measurements and ecotoxicological assays were not performed. This study provides the first comparative characterization of transformation products of recalcitrant psychotropic drugs under metal vs. BDD electrode electrolysis, offering mechanistic insights for pharmaceutical wastewater treatment optimization. Full article

Antibiotic contamination of water, particularly by tetracycline (TC), requires effective and sustainable treatment strategies. In this study, CoFe₂O₄ nanoparticles were synthesized using lime juice as a natural stabilizing agent and combined with ZnO to obtain a ZnO/CoFe₂O₄ nanocomposite for visible-light-driven TC degradation. Complementary characterization confirmed the coexistence of ZnO and CoFe₂O₄ without detectable secondary phases, with predominantly spherical and irregular particles. The composite exhibited ferromagnetic behavior, suggesting potential magnetic recovery, and showed broader visible-light absorption and a reduced band gap of 3.05 eV compared with 3.23 eV for ZnO. Although its specific surface area and pore volume were lower than those of CoFe₂O₄, the nanocomposite displayed the highest photocatalytic performance. Under the optimized conditions of pH 6, 20 mg L⁻¹ TC, and 1 g L⁻¹ catalyst, 96.8% degradation was achieved after 120 min, with a pseudo-first-order rate constant of 0.029 min⁻¹. The degradation efficiency remained 88.3% after five cycles. Scavenger experiments identified photogenerated holes (h⁺) and hydroxyl radicals (·OH) as the dominant reactive species. The improved photocatalytic activity may be associated with interfacial interactions between ZnO and CoFe₂O₄, suggesting that the green-synthesized nanocomposite has potential as a visible-light photocatalyst for TC degradation under the investigated conditions. Full article

A major limitation hindering the practical application of heterogeneous Fenton-like systems is their inherently slow reaction kinetics, particularly near neutral pH. To address this issue, a hydroxylamine (HA)-enhanced NiFe₂O₄/H₂O₂ system was developed for phenol degradation. At an initial pH of 7, with 5 mmol/L HA and 10 mmol/L H₂O₂, the system achieved 97.8% phenol degradation within 60 min, compared with 17.4% in the HA-free system. XPS analysis showed that the Fe²⁺ proportion increased from 49.1% to 53.6% and the Ni²⁺ proportion increased from 52.1% to 63.4% after reaction. These changes are consistent with HA facilitating the formation or regeneration of reduced metal species, suggesting that HA may be related to accelerated Fe³⁺/Fe²⁺ or Ni³⁺/Ni²⁺ cycling. Radical scavenging experiments and electron paramagnetic resonance (EPR) results indicated that identified hydroxyl (•OH) and superoxide (O₂•⁻) radicals were the predominant reactive species. Metal-leaching and catalyst-removal experiments indicated that both heterogeneous and homogeneous processes contributed to phenol degradation. The results provide mechanistic insights into HA-enhanced H₂O₂ activation while also highlighting the need to consider metal leaching, HA-derived nitrogen products, and catalyst reusability. Full article

Despite the traditional application of Sophora moorcroftiana seeds (SMS) in Tibetan medicine for heat-clearing, damp-drying, anti-inflammatory and detoxifying properties, the anti-inflammatory mechanisms of SMS remain insufficiently understood and warrant systematic investigation. This study evaluated the protective effects of an ethanolic SMS extract against lipopolysaccharide (LPS)-induced oxidative stress and inflammation in RAW 264.7 macrophages, with emphasis on the p62/Keap1/Nrf2 signaling pathway. In vitro, the extract exhibited significant DPPH, ABTS and ·OH radical scavenging activities, as well as ferric-reducing antioxidant power, in a clear concentration dependent manner. An inflammatory model was established by stimulating RAW 264.7 cells with LPS, followed by treatment with graded concentrations of the ethanolic SMS extract. The extract significantly reduced LPS-induced nitric oxide production and decreased the secretion of TNF-α, IL-6 and IL-1β, while suppressing iNOS and COX-2 expression at both mRNA and protein levels. In parallel, the extract alleviated oxidative stress, as evidenced by reduced intracellular reactive oxygen species (ROS) and MDA levels, increased antioxidant defenses including SOD, GSH and CAT, and decreased LDH release. At the protein-expression level, SMS treatment was accompanied by differential changes in p62, Keap1, total Nrf2 and HO-1 expression, suggesting that its effects may involve regulatory processes associated with cellular stress and antioxidant defense. Collectively, the ethanolic extract of SMS attenuated LPS-induced inflammatory and oxidative stress responses in RAW 264.7 macrophages. These effects may be associated with the suppression of inflammatory mediator production, reduction in the cellular oxidative stress burden and modulation of proteins involved in cellular stress responses and antioxidant defense. Full article

Monascin, a yellow azaphilone pigment derived from Monascus fermentation, undergoes significant photo-degradation that limits its applications. This study reveals that free radical formation, particularly hydroxyl radicals (·OH) generated via H₂O₂ photolysis, is the primary mechanism driving monascin photo-degradation. Dissolved oxygen synergistically accelerates degradation, whereas deoxygenation reduces radical yield by 68% and lowers the degradation to 5%. Enzymatic scavengers confirmed H₂O₂ as the critical ·OH precursor: catalase reduced radicals by 61% and suppressed degradation to 7%, while superoxide dismutase exhibited moderate effects. Natural antioxidants ascorbic acid and α-lipoic acid (ALA) protected monascin concentration-dependently, with ALA showing superior photo-protection (68% degradation reduction) due to its broad ROS-scavenging capacity. These findings establish H₂O₂-derived ·OH as the primary destructive species and identify oxygen exclusion, H₂O₂ decomposition, and radical scavenging as effective photo-stabilization strategies. Full article

In this work, we report the synthesis of a photocatalytic system based on impregnating g-C₃N₄ quantum dots (CNQDs) onto the surface of exfoliated graphitic carbon nitride (CN). The CNQDs were prepared using a top-down strategy via a hydrothermal route and then grafted onto exfoliated g-C₃N₄ under solvothermal conditions. The prepared CNQDs/CN composites were characterized using several techniques, including X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy (PL), and nitrogen physisorption. According to XPS analysis, a slight increase in the O 1s signal in the 1-CNQDs/CN sample could indicate a higher amount of adsorbed hydroxyl groups, which would favor the dispersion of the powder material in the aqueous medium. The photocatalytic degradation of the antibiotic levofloxacin (LEVO) was assessed using the CNQDs/CN samples, with the sample impregnated with 1 wt.% of CNQDs demonstrating the highest photocatalytic performance under UV-vis radiation conditions. Likewise, the 1-CNQDs/CN sample also exhibited the lowest photoluminescence emission (λ_exc = 315 nm), indicating that the presence of g- C₃N₄ quantum dots contributed to the decrease in the recombination rate of the photogenerated electron–hole pairs in the photoexcited graphitic carbon nitride. The stability tests revealed a modest performance reduction of 21% over three cycles. From the photocatalytic tests using scavenger agents, it was determined that hydroxyl (·OH) and superoxide (·O₂⁻) radicals are the reactive species that govern the levofloxacin photodegradation under experimental conditions. Consequently, we determined a photocatalytic mechanism consistent with the results. Full article

This study analyzes a low-cost potassium feldspar mineral from Chihuahua, Mexico, for removing cationic dyes (methylene blue and rhodamine 6G) from water. The raw mineral, characterized by Rietveld refinement as a polymineralic composite of sanidine (49 vol%), muscovite (27 vol%), calcite (16 vol%), and anorthoclase (7 vol%), demonstrated significant dual functionality. In darkness, it acted as an effective adsorbent, achieving 98% and 76% removal of MB and R6G, respectively, after 120 min, with adsorption behavior fitting the Langmuir isotherm. Under solar irradiation, the mineral facilitated photocatalytic degradation, evidenced by a faster intensity decrease and a shift in the absorption bands, and the near-complete decolorization of the dyes. The degradation kinetics were significantly accelerated in a synergistic advanced oxidation process (AOP) with added hydrogen peroxide (H₂O₂), achieving 98% degradation for MB and 93% degradation for R6G within 15 min, compared with 97% for MB and 65% for R6G under sunlight irradiation alone. Kinetic analysis revealed that the process consistently followed a pseudo-second-order model, indicating a surface-controlled mechanism dependent on dye concentration and the availability of active sites. Additional fitting with the Elovich and Avrami models suggested heterogeneous surface behavior and multistep degradation pathways, implying that the overall process involved concurrent adsorption, surface-mediated catalytic reactions, and oxidative degradation driven by photogenerated reactive species. Additionally, the scavenger tests revealed that the dominant reactive species depended on the presence of ${\mathrm{H}}_2{\mathrm{O}}_2$: ${\mathrm{O}}_2^{•-}$ radicals prevailed in the peroxide-free system, whereas $•\mathrm{OH}$ radicals dominated under ${\mathrm{H}}_2{\mathrm{O}}_2$- assisted conditions. Photoluminescence spectroscopy analysis provided mechanistic insights, tracking the evolution of dye monomers, dimers, and aggregates, confirming structural degradation of the dyes and revealing the formation of specific fluorescent intermediates. Together, these findings highlight the mineral’s potential as an abundant, eco-friendly material for solar-driven wastewater treatment. Full article

Tetracycline hydrochloride (TCH) contamination poses serious environmental risks due to its persistence and bioaccumulation. Here we present an oxygen-vacancy-enriched BiVO₄/TiO₂ S-scheme heterojunction (5% BVO/TO) synthesized via a one-step solvothermal method. Under visible light (λ  >  420 nm), this composite achieves 78.8% TCH degradation in 80 min, outperforming TiO₂ (69.5%) and BiVO₄ (34.1%). Its rate constant (0.0198 min⁻¹) is 1.4 and 4.0 times higher than TiO₂ and BiVO₄, respectively, while retaining over 70% activity after four cycles. XPS and EPR confirm that oxygen vacancies serve as electron traps to suppress recombination, and UPS combined with DFT calculations validates directional electron transfer from BiVO₄ to TiO₂. Radical scavenging tests and in situ EPR reveal h⁺ > •OH > •O₂⁻ as the dominant reactive species. This study offers a robust design strategy for OV-enhanced S-scheme photocatalysts toward efficient, sustainable degradation of antibiotic pollutants. Full article

Proanthocyanidins, a new class of potent antioxidants, are recognized for their strong in vivo activity and occur in high abundance in Lycium ruthenicum. Although the extraction of these compounds from this plant has been extensively investigated, their inherent instability imposes stringent demands on the extraction process. Natural deep eutectic solvents (NADESs) have emerged as attractive alternatives for isolating bioactive constituents from plant materials thanks to their favorable biocompatibility, high extraction efficiency, and environmentally benign nature. Therefore, we have developed an efficient and green NADES-assisted ultrasonic extraction method for recovering proanthocyanidins from Lycium ruthenicum. Among the fourteen NADES formulations screened, the choline chloride–glycerol system (1:5 molar ratio, 30% v/v water) afforded the highest extraction yield. Single-factor experiments, combined with response surface methodology, led to the optimal conditions: solid-to-liquid ratio 1:15 g/mL, ultrasonic power 240 W, temperature 40 °C, and time 30 min. Under these conditions, the proanthocyanidin yield reached 12.19%, markedly outperforming that obtained with conventional methanol extraction. Kinetic analysis indicated that the extraction process conformed to the Logistic model, with coefficients of determination (R²) greater than 0.967 across the entire temperature range studied (20–50 °C). In vitro antioxidant assays further revealed that the extract exhibited significant concentration-dependent scavenging activities against •OH, DPPH•, and ABTS⁺• radicals. The IC₅₀ values of proanthocyanidin extracts for •OH, DPPH•, and ABTS⁺• were 0.029 mg/mL, 0.56 μg/mL, and 0.011 mg/mL, respectively. Overall, these results establish a sustainable NADES-based protocol for the extraction of proanthocyanidins from Lycium ruthenicum, and underscore their promise as natural antioxidants for functional food and pharmaceutical uses. Full article

Inonotus is a globally distributed genus within the Hymenochaetales, with certain species widely used in traditional herbal medicine. Here, a new species, I. chrysosporus, was identified as a sister clade to I. hispidus based on morphological, molecular, and vegetative incompatibility characteristics. The growth of I. chrysosporus on two substrate formulations—(1) 60% (wt:wt) Dicranopteris dichotoma, mixed with 18% corncob, 20% wheat bran, 1% gypsum, and 1% lime (GS), and (2) 78% sawdust wood chips (SS)—was compared in terms of the accumulation of bioactive components and the corresponding biological activities. On both substrates, I. chrysosporus exhibited high nutritional value, with high protein and mineral contents, low fat content, and a high proportion of medicinal amino acids. However, significant variations in the profiles of active constituents were observed, with cultivation on the GS formulation promoting the accumulation of bioactive polysaccharides, whereas growth on SS resulted in the accumulation of polyphenols. Aqueous extracts of I. chrysosporus mushrooms derived from both growth substrates exhibited potent antioxidant activities. Correlation analyses indicated that polysaccharide content was positively associated with ·OH scavenging activity and that polyphenol content was correlated with strong DPPH radical scavenging activity and high ferric-reducing antioxidant power (FRAP). This study provides a foundation for the comprehensive development and utilization of the newly described I. chrysosporus species. Full article

Most traditional photocatalysts exist in powder form and have the disadvantage of being difficult to recycle and causing secondary pollution to the environment after use. To overcome this drawback, this study combined natural biopolymer (silk fibroin (SF)) with a previously developed titanium-based photocatalytic material P/Ag/Ag₂O/Ag₃PO₄/TiO₂ (PAgT) and fabricated a novel SF/PAgT fiber membrane via electrospinning. During the synthesis process, through adjusting the mass concentration of the PAgT dopant (0–0.30 g/mL), a series of photocatalytic fiber membranes were prepared. The morphology and structure of the as-prepared membranes were characterized by various analytical methods, including scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), contact angle (CA) and thermogravimetric analysis (TGA). The SEM images confirmed that the SF/PAgT composite membrane possessed a protrusive and spindle-shaped structure. FT-IR results verified that the primary structure of SF in all the as-prepared SF/PAgT membranes belonged to the Silk II type. The binding of SF with the PAgT photocatalyst did not disrupt the chemical structure and original properties of SF. Moreover, the XRD and CA measurements indicated that the SF/PAgT-4 fiber membrane exhibited the stronger diffraction peaks of anatase TiO₂ crystal structure and enhanced hydrophilicity. The experimental results clarified that the PAgT photocatalyst was successfully loaded onto the SF fiber membrane by electrospinning. To evaluate the performance of the developed visible-light-driven photocatalytic fiber membranes, Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) were selected as representative bacteria strains. The results demonstrated that SF/PAgT-4 exhibited the optimal antibacterial activity and can completely inactivate 10⁷ CFU/mL of E. coli and S. aureus within just 30 min and 60 min treatment, respectively, indicating the optimal doping mass concentration of PAgT during the synthesis process was 0.20 g/mL. Furthermore, the scavenger study proved that during the photocatalytic disinfection process by SF/PAgT-4, all three radicals, including ·OH, h⁺ and ·O₂⁻, participated in the current photocatalytic disinfection system. They were capable of attacking the bacterial cells, causing the cell membrane injury, thereby leading to the intracellular component leakage and inducing extensive bacterial inactivation. Hence, by virtue of its excellent recyclability (during five cycles) and thermal stability (below 250 °C), the developed SF/PAgT-4 fiber membrane holds immense potential for highly efficient and sustainable utilization in practical water treatment applications. Full article

In this study, we combine experimental and computational approaches to elucidate a density functional theory (DFT)-derived mechanism for superoxide scavenging by resveratrol, piceatannol, and oxyresveratrol. Using rotating ring–disk electrode (RRDE) hydrodynamic voltammetry, the superoxide radicals are generated in situ, allowing direct measurement of antioxidant activity. Data show that the catechol-containing piceatannol is approximately four times more active than resveratrol, while resveratrol and oxyresveratrol exhibit similar efficiencies, indicating that the additional 2′-OH group in oxyresveratrol has minimal impact. Vitamin C (ascorbic acid) facilitates scavenging by acting as a proton donor for resveratrol, piceatannol, and 4′-OH oxyresveratrol, but it is unable to deprotonate the 2′OH group of oxyresveratrol. The experimental results suggest a superoxide dismutase (SOD)-like mechanism, obtained from energetically feasible DFT calculations, in which these stilbenes convert two superoxide anions into H₂O₂ and O₂, helped by vitamin C. Mechanistically, the first superoxide is reduced by abstracting a hydroxyl-group hydrogen atom, while the second undergoes oxidation via π–π interaction with the aromatic system, releasing O₂. Notably, resveratrol can be regenerated through a catalytic cycle involving vitamin C. These data underscore the SOD-mimicking properties of dietary polyphenols and suggest a need to reevaluate resveratrol’s clinical utility regardless of its low bioavailability. Full article

Background: Type 2 diabetes mellitus (T2DM) is a global health challenge characterized by chronic hyperglycemia and oxidative stress. Pithecellobium dulce root has long been recognized for its antidiabetic potential; however, its specific bioactive constituents and mechanisms of action remain poorly defined. This study aimed to evaluate the antidiabetic and antioxidant properties of extracts and isolated molecules from P. dulce root bark. Methods: The DCM/MeOH crude extract of P. dulce root bark was fractionated with n-hexane (PDEH) and ethyl acetate (PDAE), followed by chromatographic purification and spectroscopic characterization, yielding seventeen compounds (1–17). The antioxidant activity (DPPH, ABTS, FRAP) and antidiabetic potential of PDEH, PDAE, and 1–17 were assessed in vitro using yeast-derived enzymes and in silico (targeting human α-glucosidase [PDB: 2QLY] and human α-amylase [PDB: 4GQR]). The in vitro α-glucosidase experiments used saccharomyces cerevisiae enzyme, which varies from the human target. Therefore, these results should be taken as preliminary screening data that needs confirmation with human enzymes. Results: Compound 1 was identified as new, while 2 was isolated for the first time from a natural source. The cell-free chemical tests DPPH, ABTS, and FRAP measured antioxidant capability. These tests quantify radical-scavenging and electron-transfer capabilities in vitro and are preliminary chemical screening methods. They do not directly represent biological antioxidant activity in cells or organisms. PDEH demonstrated strong radical scavenging against DPPH (IC₅₀ = 15.30 μg/mL) and ABTS (IC₅₀ = 12.80 μg/mL), while pristriol (16) showed ferric reducing power (EC₅₀ = 4200 μM FeSO₄/g). Enzyme inhibition assays demonstrated activity against α-amylase (IC₅₀ 53.88–112.24 µg/mL; acarbose IC₅₀ = 91.20 µg/mL) and α-glucosidase (IC₅₀ 18.38–136.88 µg/mL; acarbose IC₅₀ = 11.31 µg/mL). Compounds 15, 1, and 2 showed superior activity compared to acarbose for α-amylase, with effect sizes (Cohen’s d) of 2.15, 0.94, and 0.82, respectively, and IC₅₀ values of 53.88, 88.15, and 92.62 µg/mL; for α-glucosidase, IC₅₀ values were 18.38, 39.25, and 36.40 µg/mL, respectively. Docking studies supported these findings, revealing binding energies of −9.08, −8.34, and −7.22 kcal/mol for compounds 1, 2, and 15 with α-amylase, and −10.35 and −9.79 kcal/mol for compounds 1 and 2 with α-glucosidase. ADME profiling further identified 1 and 2 as promising lead candidates for dual-enzyme inhibition. Conclusions: P. dulce root bark represents a potent source of bioactive molecules with both antioxidant and dual-enzyme-inhibitory properties. These findings validate its traditional use and highlight its potential in the development of multitarget therapies for T2DM management. Full article