Search Results (894)

This review explores the biological properties and application potential of native, technical, and modified lignins, with a focus on their antioxidant, antimicrobial, and anti-inflammatory activities. Native lignin generally preserves more of its original phenolic architecture and thus shows stronger intrinsic biological activity. This is likely due to its more homogeneous structure, which makes its physicochemical behavior more predictable compared with highly processed technical lignins. Among technical lignins, organosolv and soda lignin appear the most promising due to their sulfur-free nature, lower condensation, and higher reactivity. At the monomer level, catechol-type phenolics show the highest antioxidant potential, while vanillin remains the most attractive lignin-derived monomer because it combines bioactivity with direct application potential in food, pharmaceutical, and cosmetic systems. Comparison of modification strategies indicates that phenolic grafting, esterification, and carboxylation are more practical for scale-up than complex multistep polymer grafting. In particular, gallic acid grafting produced some of the strongest results, including near-complete 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) scavenging, 98.7% 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical inhibition, and a fourfold increase in phenolic hydroxyl content, whereas other modified lignins also showed improved antimicrobial and anti-inflammatory effects. Overall, mild and green lignin modification, especially with food-safe phenolic compounds, appears to be the most promising strategy for future food and human health applications. Full article

Polydopamine (PDA) is a promising biomimetic material, but its structural complexity hinders rational control over its light absorption properties. The purpose of this study was to develop a simple post-synthetic method to tune the absorption spectrum of PDA using Bobbit’s salt (4-acetylamino-2,2,6,6-tetramethylpiperidine-1-oxoammonium salt) as a mild oxidant. Conventional PDA nanoparticles were treated with Bobbit’s salt either in pure water or in a 1:1 methanol–water mixture to obtain two modified samples. Structural analysis conducted using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and mass spectrometry demonstrated that Bobbit’s salt selectively oxidized catechol units to ortho-benzoquinone moieties, with the C–O/C=O ratio decreasing from 71:29 in the untreated PDA to 51:49 in the water-treated sample, while nitrogen functionalities remained unchanged. Consequently, the sample prepared in pure water showed generally lower absorbance across the visible–near-infrared range, whereas the sample prepared in the methanol–water mixture exhibited enhanced ultraviolet absorption but reduced near-infrared absorption. When coated onto polyvinylidene fluoride membranes, the water-treated PDA produced a brighter and more reddish-yellow appearance. On transparent poly(methyl methacrylate) substrates, the same coating also enhanced ultraviolet blocking and reduced visible transmittance. These findings conclude that Bobbit’s salt is an effective and selective reagent for tailoring the optical properties of PDA, with potential applications in protective coatings and light-modulating materials. Full article

Endogenous estrogens are implicated in carcinogenesis through both estrogen receptor-mediated cell proliferation and the direct genotoxicity of reactive metabolites. Oxidative metabolism of estrogens produces catechol estrogens that are further converted to electrophilic ortho-quinones capable of alkylating DNA. The prevailing model of mutagenesis proposes that these N3Ade and N7Gua adducts depurinate to form abasic sites that induce mutations initiating hormone-related cancers. However, the mutation spectrum observed in experimental data is inconsistent with this mechanism, and synthetic studies of estrogen-DNA adducts have relied on acidic conditions that artificially promote depurination, leaving stable N7-dG lesions poorly understood. To address this, we synthesized stable N7-dG catechol and estrone adducts using 2′-fluorinated deoxyguanosine, a modification that inhibits N-glycosidic bond cleavage. ROESY 2D NMR spectroscopy revealed through-space correlations consistent with a preferred anti-conformation in solution, supported by molecular modeling. Structural analysis suggests that these cationic aryl adducts likely preserve the Watson–Crick base pairing edge but may promote tautomerization capable of altering base pairing and generating G-to-A mutations. These findings provide the first synthesized stable models of N7-dG estrogen adducts and may support an alternative mechanism of estrogen-induced mutagenesis independent of depurination, enabling future biochemical investigations of related DNA repair and mutagenesis. Full article

Background/Objectives: Topical hemostatic biomaterials are used to control diffuse parenchymal bleeding during hepatectomy. TachoSil is a widely used standard fibrin sealant patch. We evaluated the efficacy and safety of InnoSEAL Plus DL, a novel bioinspired absorbable chitosan–catechol/gelatin hemostatic patch, compared with TachoSil. Methods: This multicenter, randomized, single-blind, active-controlled, parallel-group noninferiority trial enrolled adults undergoing hepatectomy who had persistent oozing from the hepatic transection surface despite primary hemostasis. Participants were randomized in a 1:1 ratio to receive InnoSEAL Plus DL or TachoSil. The primary endpoint was hemostatic success within 3 min of application, with a prespecified noninferiority margin of −19.4 percentage points (pp). Safety was assessed up to 30 days postoperatively. Results: Ninety patients were randomized (45 per group). In the per-protocol population, 3 min hemostatic success was achieved in 100.0% of both the InnoSEAL Plus DL (43/43) and TachoSil (41/41) groups. The risk difference was 0.0 pp, and the lower bound of the one-sided 97.5% confidence interval was −8.2 pp, confirming noninferiority. The mean time to hemostasis was similar between groups (1.2 vs. 1.3 min), and no intraoperative rebleeding occurred. Adverse events were reported in 78/90 patients (86.7%) and serious adverse events in 6/90 (6.7%); the latter were typical post-hepatectomy events unrelated to the study devices. No deaths were reported. Conclusions: InnoSEAL Plus DL was noninferior to TachoSil for achieving rapid intraoperative hemostasis during hepatectomy, with no unexpected safety concerns. This bioinspired hemostatic patch is an effective alternative to fibrin sealant, without the use of human-derived proteins. Full article

The causative event in transmissible spongiform encephalopathies is the misfolding of the prion protein (PrP), a process influenced, in a way that is not yet fully understood, by transition metal ions, particularly copper, which modulate folding, aggregation, and redox activity. In this study, we investigated the interaction of copper(II) ions with the prion fragment PrP(95–126), which includes the non-octarepeat high-affinity sites His96 and His111, as well as an amyloidogenic tail involved in PrP misfolding and membrane interaction. UV–vis and circular dichroism analyses revealed the predominant formation of a 1:1 Cu/PrP(95–126) complex, accompanied by modest restructuring, consistent with an increased aggregation propensity upon copper binding. The Cu/PrP(95–126) complexes exhibited limited redox activity toward catechol substrates, which was further reduced in membrane-mimetic systems such as SDS micelles and large unilamellar vesicles (LUVs). His96 appears not to play a critical role in copper coordination or redox activation. This study explores the coordination modes and reactivity of copper(II) with PrP, as well as employing a membrane mimic, aspects that are still highly controversial in the literature, providing insights for further in vitro studies. Full article

Urinary cancers present a severe clinical challenge due to high recurrence rates. Standard intravesical therapies suffer from limited efficacy because of the urinary tract’s robust physiological defenses, namely, the dynamic washout effect during voiding and highly restrictive urothelial barriers, such as the anti-adhesive glycosaminoglycan layer and intercellular tight junctions. This review aims to explore how biomimetic engineering can overcome these obstacles by transitioning drug delivery from passive carriers to active, nature-inspired systems. We conducted a comprehensive review of the recent literature focusing on biomimetic strategies for intravesical drug delivery and urinary cancer theranostics. The analyzed approaches are categorized into chemical biomimicry (such as adhesion and camouflage) and structural/functional biomimicry (including adaptive devices and microrobots). Biomimetic strategies significantly enhance targeted drug retention and tissue penetration. Chemical biomimicry, utilizing mussel-inspired catechol chemistry and cell membrane camouflage, effectively bypasses the urothelial anti-adhesive defenses and reduces the immune clearance. Structural and functional biomimicry, such as naturally derived carriers and actively propelled magnetic or biohybrid microrobots, enables the precise spatial localization and controlled payload release in dynamic fluid environments. Furthermore, lab-on-a-chip technologies and patient-derived organoids (PDOs) offer scalable platforms for screening cargo-specific efficacies and tailoring treatments, providing a crucial bridge to personalized precision medicine. Integrating nature-inspired designs with advanced nanotechnologies provides a highly promising pathway with which to overcome the mechanical and biological barriers of the urinary tract. These biomimetic innovations hold the potential to shift the therapeutic paradigm for urinary oncology, paving the way for more efficient, targeted, and personalized precision medicine. Full article

This review examines how plant polyphenols enable multifunctional textiles, offering a sustainable alternative to synthetic dyes and nanomaterial-based treatments. A literature search (2001–2025) identified 105 peer-reviewed studies across eight functional areas. Abundant in agricultural and industrial byproducts, plant polyphenols act as natural colorants, bio-adhesives, and performance enhancers—providing coloration, antibacterial activity, UV protection, flame retardancy, deodorization, antioxidant capacity, superhydrophobicity, and more. Their catechol and pyrogallol groups bind strongly to natural and synthetic fibers via hydrogen bonding, π–π stacking, and metal chelation, ensuring durable, nontoxic functionality. We analyze structure–function links and scalable methods, including pad-dry-cure and metal–phenolic network (MPN) assembly, which were validated against ISO, ASTM, and AATCC standards. Polyphenol-based textiles match or exceed conventional ones in key metrics, with added benefits: full biodegradability, low ecotoxicity, and skin compatibility. Key advances include enzymatic polymerization for wash-stable color, MPN tuning for customizable functions, and using waste-derived polyphenols. However, major challenges remain: narrow color range (mostly yellow, brown, black) and poor wash/UV resistance, leading to rapid fading and loss of antibacterial/UV protection after laundering. Solving these is a top priority for future work. Overall, this review delivers a practical, science-based roadmap for high-performance, sustainable textiles that align with the Sustainable Development Goals and meet real-world needs in healthcare, sportswear, and smart wearables. Full article

Urushiol, the key component of natural lacquer, is emerging as a versatile bio-based phenolic platform for advanced polymer systems. Its unique catechol structure, combined with an unsaturated aliphatic side chain, provides multiple reactive sites, enabling diverse chemical pathways and tunable network architectures. This review presents a systematic analysis of urushiol-based materials within a “structure–reaction–property–application” framework. The intrinsic reactivity of urushiol, including oxidative polymerization, dynamic covalent bonding, and metal–phenolic coordination, is correlated with the formation of crosslinked networks exhibiting controllable mechanical properties, strong interfacial adhesion, and stimuli responsiveness. Recent advances in functional coatings, self-healing and reversible polymers, bioactive materials, and cultural heritage conservation are highlighted. Special emphasis is placed on dynamic network design and low-sensitization strategies to overcome limitations of traditional lacquer systems. Finally, key challenges and future directions toward controllable curing, structure–property relationships, and sustainable material design are discussed, positioning urushiol as a bridge between traditional materials and next-generation functional polymers. Full article

The MarR (multiple antibiotic resistance regulator) family regulators, which are widely conserved across various organisms, play pivotal roles in metabolism, stress response mechanisms, and virulence factor production. However, the regulatory functions of these factors in the degradation of aromatic compounds within Corynebacterium glutamicum remain largely uncharacterized. In this study, we identified a MarR-type regulator, designated AcsR (encoded by ncgl2425), which directly represses the expression of the catechol 2,3-dioxygenase gene ncgl2007 (c23o) and the heavy metal (nickel) transport system permease gene ncgl2351, while activating the expression of ncgl2258 encoding an ABC-type C4-dicarboxylate-binding periplasmic protein. AcsR binds specifically as a dimer to a 6 bp inverted repeat sequence, and this binding is disrupted by catechol in vitro. Correspondingly, catechol induces the expression of c23o in vivo. Phenotypic analysis revealed that the ΔacsR mutant exhibited enhanced resistance to multiple aromatic compounds but increased sensitivity to antibiotics, heavy metals, and oxidants. Collectively, these findings demonstrate that AcsR is an important regulator of stress adaptation in C. glutamicum and provide new insights into the regulatory mechanisms of aromatic compound degradation in this industrially important bacterium. Full article

Lubricants are essential for water-based drilling fluids. Catechol-based lubricants provide improved lubrication performance owing to their strong adhesion ability through the formation of coordination bonds inspired by mussel adhesion. However, the conventional synthetic ester and amide lubricants suffer from loss of adhesive capability due to hydrolysis and autoxidation. Inspired by mussels and melanin biosynthesis, a biomimetic strategy was developed to synthesize a high-adhesion lubricant with good stability via thiol-quinone Michael addition to restore and stabilize the catechol moiety. Bisphenol A was oxidized to the corresponding quinone using 2-iodoxybenzoic acid. Subsequent Michael addition reaction with 1-octadecanethiol produced a thiol-functionalized lubricant containing catechol moieties and long alkyl chains through an S-catecholyl linkage. Biomimetic principles were incorporated into both the molecular structure and the synthetic route, emulating the structural and functional features of mussel adhesion and melanin biosynthesis. Octadecanethiol provided sulfur-containing extreme-pressure functionality and contributed to strong adsorption on metal surfaces. The molecular structure was confirmed by FTIR, ¹H NMR, and ¹³C NMR. The thiol-functionalized lubricant formed strong coordination with Fe³⁺ and Fe²⁺ ions across a wide pH range, with an apparent complexation stoichiometry of 1:1 and conditional stability constants of 4.09 and 5.02, respectively. Bis-coordination formed a cross-linking network. It exhibited good resistance toward autoxidation and thermal stability up to 350 °C. In bentonite-based drilling fluids, the extreme pressure lubrication coefficient and adhesion coefficient at a 1% addition were 0.06 and 0.07, respectively. The coefficient of friction and wear scar diameter were 0.09 and 0.63 mm, respectively. The increased contact angle confirmed strong adsorption of the lubricant on metal surfaces. The lubricant combined strong adhesion, high stability, and excellent compatibility with drilling fluids, highlighting its potential as an advanced biomimetic lubricant. This biomimetic thiol-quinone addition strategy provides an effective approach to overcome the instability of conventional catechol-based lubricants. Full article

This study evaluated the sustainability of removing phenolic compounds from olive mill effluents using a nanobiochar synthesized from olive pomace. Catechol, tyrosol, hydroxytyrosol, and homovanillic alcohol were chosen as model pollutants due to their presence in agro-industrial wastewater. The surface morphology, elemental composition, crystallographic structure, functional groups, porosity, and thermal stability of the nanobiochar were investigated by SEM, EDX, XRD, FTIR, BET analysis, and TGA/DTA. The developed nanobiochar exhibited a predominantly amorphous carbon structure, enriched in carbon (85.6%), with localized graphitic domains. Its mesoporous architecture (S_BET = 15.478 m² g⁻¹; Dp = 2.14 nm) promotes accessibility to active sites, while its thermal stability confirmed its suitability for adsorption applications. In this batch adsorption study, the technological aspect considered is the influence of operating parameters on adsorption efficiency, using kinetic and equilibrium models. Pseudo-first-order and pseudo-second-order kinetic models, as well as Freundlich and Langmuir isotherms, were used to analyze the experimental data. The pseudo-second-order model proved to be the most suitable for describing adsorption, suggesting that the process is primarily dominated by chemisorption. Similarly, the Langmuir model gave the least satisfactory results regarding equilibrium data, indicating monolayer adsorption on homogeneous active sites. The adsorption capacity of phenolic compounds was variable. The highest adsorption capacities were observed for catechol (250 mg g⁻¹), tyrosol (19.23 mg g⁻¹), homovanillic alcohol (15.38 mg g⁻¹), and hydroxytyrosol (13.16 mg g⁻¹). The results of this research indicate that adsorption affinity depends on molecular structure and electronic properties. Furthermore, computer modeling based on molecular simulations and electronic descriptors was performed to explain the adsorption mechanism. Linear regression, principal component analysis, and elastic regression revealed strong correlations between adsorption parameters and molecular descriptors. These results demonstrate that olive pomace-based nanobiochar is an environmentally friendly adsorbent for the treatment of phenolic effluents, with adsorption primarily controlled by surface interactions. Full article

Using density functional theory (DFT) and the Gaussian 09 program, the study calculated Gibbs free energy to understand how easily each NP can transform. Results showed that only 2,6-dinitrophenol (2,6-DNP) and 2-chloro-6-nitrophenol (2-Cl-6-NP) had Gibbs free energies above 0 kJ/mol. The study also evaluated the toxicity of the NPs, leading to the identification of trinitrophenol (TNP), 2-chloro-4-nitrophenol (2-Cl-4-NP), and 2-nitrophenol (2-NP) with the highest risk scores. In the present study, binding energies were used only as comparative indicators of enzyme–substrate interaction favorability within a screening framework, rather than direct measures of catalytic degradation efficiency. The enzyme 1,2-dioxygenase from Acinetobacter baylyi ADP1 showed strong degradation effects on catechol, with significant binding energies for 2-NP, 2-Cl-4-NP, and TNP. The PS-AOP changed the degradation environment, which reduced enzymatic efficiency. The study also modified specific amino acids in enzymes to improve their performance. For example, the enzyme 1DLT-6 had a degradation increase of nearly 27% compared to the reference enzyme. Finally, we tried to measure the impact of different forces on the breakdown of nitrophenols by enzymes. We used a two-dimensional amino acid map based on enzyme–ligand interactions and a visualization of non-covalent interactions. Our findings show that van der Waals forces and electrostatic forces are the main factors affecting how well the material breaks down. From a sustainability perspective, the study highlights a promising strategy for mitigating secondary pollution, improving the environmental compatibility of PS-AOP-based remediation, and supporting safer and more sustainable restoration of petroleum hydrocarbon-contaminated soil and groundwater. These findings help strengthen the theoretical basis for developing greener post-oxidation remediation pathways. Full article

Rutin is a naturally occurring flavonoid with well-documented antioxidant and pharmacological properties. In this study, a manganese(II) complex with rutin (Mn(II)-Rut) was synthesized in a solid state and characterized using FT-IR, Raman spectroscopy, thermogravimetric and elemental analysis, confirming its composition as C₂₇H₂₇O₁₆Mn₂·5H₂O. The IR spectra indicated that rutin coordinates manganese ions through the carbonyl group at the C4 position and the hydroxyl group at the C5 atom, as well as the catecholic system. The antioxidant potential of both Mn(II)-Rut and rutin was evaluated using several spectrophotometric assays. The Mn(II)-Rut complex showed stronger activity in most spectrophotometric assays than rutin, i.e., in ABTS assay, 50.37 ± 2.64% vs. 41.49 ± 1.38%; in CUPRAC assay, 0.468 ± 0.006 mM Trolox vs. 0.379 ± 0.007 mM Trolox; and FRAP assay, 0.201 ± 0.002 µM vs. 0.189 ± 0.003 µM. However, the DPPH assay complex showed a diminished effect compared with ligand (IC₅₀ 2.78 ± 0.13 µM vs. 0.98 ± 0.04 µM for rutin). Quantum-chemical calculations were also performed using the Gaussian09 program to determine the optimized geometric structures, electron charge distribution, and the energies of the HOMOs and LUMOs in the analyzed molecules in order to discuss the antioxidant mechanism of the molecules. Enzymatic assays demonstrated that the Mn(II) complex with rutin exhibited a stronger α-amylase inhibitory effect compared to free rutin, which showed the potential antidiabetic activity of the compound. The results suggest that the Mn(II) complex of rutin possesses better antioxidant and α-amylase inhibitory activity than the ligand alone. Full article

Nonsteroidal anti-inflammatory drugs such as phenylbutazone (PBZ) are among the most widely used medications globally due to their effectiveness in relieving pain and reducing inflammation. This study aims to detect PBZ with metallic particle-based electrochemical sensors using cyclic voltammetry (CV) in the presence of catechol as a redox probe. The approach focuses on evaluating the electrochemical behaviour of PBZ under different experimental conditions and optimizing the detection parameters to develop a simple, rapid, and cost-effective analytical method suitable for this pharmaceutical compound in lab practice. CV was performed using four types of screen-printed electrodes, each modified with different transitional metal particles, in potassium ferrocyanide/potassium ferricyanide, catechol, and catechol-PBZ solutions to study the electrochemical response and detection capability for PBZ. The best performance characteristics were obtained for the sensor modified with Ir particles that detect PBZ, with a linearity range of 0.01 to 1.00 μM and a detection limit of 1.53 nM. Additionally, Fourier-transform infrared spectroscopy (FT-IR) was used to characterize the PBZ in pharmaceuticals. The method using an iridium-modified sensor developed in this study allows the accurate detection of PBZ in pharmaceuticals with a relative error lower than 4%. Full article

Consumer preference for clean-label products is driving interest in natural antioxidants and antimicrobials that can replace synthetic preservatives. Ziziphus mauritiana (sidr), a resilient desert tree native to the arid Gulf region, has being tested as a multifunctional bio-preservative. This study evaluated the extraction yield, total phenolic content (TPC), total flavonoid content (TFC), antioxidant and antimicrobial activities, and poultry meat-preserving potential of Z. mauritiana. Methanol and ethanol produced the highest extract recoveries, with bark exhibiting the maximum extraction yield of up to 10.7 mg/100 g. Fruits demonstrated the highest total phenolic content (TPC) of around 175 mg gallic acid equivalents per gram (GAE/g) and total flavonoid content (TFC) of around 7.4 mg catechin equivalents per gram (CE/g), followed by leaves and bark. The antioxidant activity was significantly correlated with the concentration of phenolic compounds in the fruit extracts, which exhibited DPPH inhibition exceeding 60% in the majority of instances. The RP-HPLC investigation revealed a diverse polyphenolic profile, predominantly featuring gallic acid (up to 8.77 mg/g in leaves), catechin (6.30 mg/g in fruits), catechol, and caffeic acid. Leaf extracts showed 24 mm inhibitory zones against E. coli and Y. enterocolitica, while bark and fruit were not very effective. Adding ethanolic leaf extract (0–1%) to chicken breast meat reduced microbial degradation during chilled storage at 4 °C. At day 15, total aerobic counts reached only 5.34 log CFU/g with 1% extract compared with 8.53 log CFU/g in the control. Similar suppression was found for yeasts and molds, while challenge tests showed >3-log reductions in C. jejuni and Salmonella senftenberg. Sensory evaluation confirmed no detrimental effects on color, odor, flavor, or texture. Overall, Z. mauritiana was a valuable, renewable source of phenolic antioxidants and antimicrobial agents and showed strong promise as a natural preservative capable of improving the safety and shelf life of poultry meat in clean-label applications. Full article