Search Results (9,235)

Waste cooking oil (WCO) was investigated as a waste-derived reactive precursor for a cured organic binder in highly mineral-filled composites containing turmeric. Ten formulations selected from a broader experimental screening were prepared from WCO, sulfuric acid, quartz sand, and turmeric added at 1–7% relative to the dry mass of quartz sand. Formulation-specific thermal curing was conducted at 190–210 °C for 12–20 h. Because the binder content, acid-to-binder ratio, turmeric content, curing temperature, and curing time varied simultaneously, the study was designed as an exploratory multifactorial screening rather than as a controlled assessment of individual processing variables. FTIR, ¹H NMR analysis of acetone-soluble constituents, TGA, and SEM-EDS were combined with mechanical screening, water-absorption, contact-angle, and microbiological measurements. Bending and splitting tensile strengths ranged from 1.15 to 2.42 MPa and from 0.30 to 0.52 MPa, respectively. Water absorption ranged from approximately 4.8% to 9.0%, while water contact angles exceeded 90° for all investigated formulations. Selected formulations reduced the surviving fraction by more than 90% for Staphylococcus epidermidis and by approximately 70% for Pseudomonas aeruginosa under the applied suspension-assay conditions. The estimated C₅₀ values of 60.6–83.3 mg mL⁻¹ indicated measurable concentration-dependent responses at relatively high nominal composite concentrations. The available results support curing-associated transformation and consolidation of the WCO-derived binder phase but do not quantify crosslink density or retained organic content. Because no matched turmeric-free composite or surface/eluate pH measurements were available, the biological effects are attributed to the complete composite formulations rather than specifically to turmeric or intact curcumin. The results provide an exploratory basis for the further development of waste-derived, non-load-bearing polymer–mineral composites with functional surface and biological properties. Full article

Retinal degeneration is characterized by progressive photoreceptor loss driven by oxidative stress and chronic inflammation, yet effective mutation-independent therapeutic strategies remain limited. Lycium barbarum polysaccharides (LBPs) possess antioxidant and anti-inflammatory activities; however, the structural features responsible for their retinal protective effects remain poorly defined. In this study, crude LBP was fractionated by DEAE-cellulose ion-exchange chromatography, and the most bioactive fraction, LBPF2, was identified using H₂O₂-injured 661W cone photoreceptor-like cells. LBPF2 was subsequently characterized by high-performance anion-exchange chromatography, SEC-MALLS-RI, GC–MS methylation analysis, and one- and two-dimensional NMR spectroscopy, and its protective effects were evaluated in H₂O₂-treated 661W cells and rd10 mice. LBPF2 was identified as a homogeneous glucose-rich polysaccharide with an average molecular weight of approximately 41 kDa and a backbone mainly composed of →4)-α-D-Glcp-(1→ and →4,6)-α-D-Glcp-(1→ residues. LBPF2 reduced oxidative stress, inflammation, and apoptosis in H₂O₂-treated 661W cells, preserved retinal morphology, improved electroretinographic responses and partial retention of rhodopsin immunoreactivity relative to untreated rd10 mice, and restored redox homeostasis in rd10 mice. Pharmacological inhibition of Nrf2 using ML385 attenuated these protective effects, supporting the involvement of Nrf2/HO-1 signaling. Collectively, these findings identify LBPF2 as a structurally characterized neuroprotective polysaccharide that mitigates retinal degeneration through coordinated regulation of oxidative stress and inflammation and highlight its therapeutic potential for retinal degenerative diseases. Full article

This study examined the bioactivity profiles and secondary metabolite diversity of 64 crude extracts derived from benthic marine organisms, including 51 extracts from 34 sponge species and 13 extracts from 10 ascidian species, collected across six locations in two regions: the Gulf of Mexico (Alacranes Reef and Progreso) and the Mexican Caribbean (Cozumel, Bermejo, Mahahual, and Rio Indio) on the Yucatán Peninsula. The evaluation focused on five biological activities: cytotoxic, antialgal, antiviral, antifungal, and antibacterial. Results showed that 64.1% of the extracts displayed at least one activity, with 43.7% being cytotoxic, 35.9% antialgal, 25% antiviral, 15.6% antibacterial, and 14.1% antifungal. Using the Spearman correlation method, antifungal and antibacterial activities showed significant correlations in two sponge families, Agelasidae and Aplysinidae (ρ ranging from 0.99 to 0.97, p = 0.01–0.001). The Cozumel and Río Indio localities exhibited the highest number of bioactive extracts; notably, extracts of 15 species demonstrated specific biological activities. Furthermore, a dereplication strategy using ¹³C NMR spectroscopy was applied, aiding in the probable identification of secondary metabolites and clarifying the biological activities of recurrent species from different locations. Full article

Permeability prediction and hydraulic rock typing in carbonate reservoirs remain challenging because similar porosity values may correspond to markedly different flow capacities controlled by pore throat size, connectivity, and capillary accessibility. This study aims to develop an integrated workflow for permeability prediction and petrophysical–hydraulic rock typing of a heterogeneous dolomite reservoir using parameters that directly characterize the drainable pore throat network. Routine core analysis, centrifuge-derived capillary pressure curves, nuclear magnetic resonance $T_2$ spectra, electrical measurements, petrographic and SEM observations, and fractal descriptors were jointly analyzed. Capillary pressure curves were fitted with the Li–Horne model and transformed into equivalent pore throat radius distributions; characteristic radii $R_q$, Swanson and Capillary-Parachor parameters, irreducible water saturation, and fractal characteristics were calculated for subsequent regression analysis and rock typing. The conventional $k-\varphi$ relationship showed limited predictive capability, whereas models incorporating $R_{15}-R_{21}$ provided a more reliable permeability estimate. The best-performing relationship was close to $k\propto R^2\varphi$, supporting the interpretation of $R_{20}$ as a centrifuge-derived analog of the effective hydraulic radius. Comparison with FZI, Winland R35, NMR groups, and electrofacies showed that $R_{20}$-based typing produced a compact separation of samples by hydraulic quality. The proposed workflow is presented as a single-well proof of concept and requires validation in independent wells before application to field-scale geological and hydrodynamic models. Full article

When red-bed mudstone is directly used as fill material for building foundations, road subgrades, and similar applications, it is prone to seepage-induced deformation and instability. Amending it with montmorillonite bentonite can effectively regulate its permeability characteristics. Meanwhile, rapid and accurate prediction of the permeability coefficient is crucial for building foundations and road subgrade seepage analysis and stability assessment. This study investigated red-bed mudstone fill material modified with montmorillonite bentonite at different blending ratios. Soil–water characteristic curve tests, saturated/unsaturated permeability tests, and nuclear magnetic resonance (NMR) tests were conducted on the specimens to examine the pore evolution patterns and permeability characteristics of the modified red-bed mudstone, and a predictive model for coefficients was proposed. The results indicate that the incorporation of montmorillonite-based bentonite markedly affects the permeability properties of modified red-bed mudstone fillers. The NMR T₂ spectrum exhibits a bimodal distribution; the incorporation of bentonite and the saturation process result in a marked reduction in large pores and an increase in microporosity. The predictive model achieves higher accuracy when the montmorillonite bentonite content is high. Sensitivity analysis revealed that the maximum pore radius has a far greater influence on permeability than the pore fractal dimension and tortuosity. The research findings provide experimental evidence and theoretical models for the rapid estimation of permeability and seepage stability analysis of modified red-bed mudstone fill materials. Full article

As interface control technology has become crucial for preventing pattern collapse caused by the miniaturization of display and semiconductor devices, surfactants are essential in core manufacturing processes, including electroluminescence. Therefore, high-performance surfactants capable of achieving efficient liquid penetration and wettability control in high-aspect-ratio architectures are urgently needed. To address this need, this study suggested two glyceryl ether derivatives, 3-(hexyloxy)propane-1,2-diol (Hex-PD) and 3-((2-ethylhexyl)oxy)propane-1,2-diol (Oct-PD), alongside a monoalcohol ether derivative, 1-methoxy-3-(pentyloxy)propan-2-ol (Pen-PMO), and systematically investigated the effects of structural variation on optical transmittance, molecular polarity, and interfacial behavior. The target compounds were successfully obtained, as confirmed by ¹H NMR and FT-IR analyses. At 0.01 wt%, all three compounds showed relatively high transmittance at 248 nm. Surface tension measurements at 0.1 wt% revealed values of 38, 35, and 31 mN/m for Hex-PD, Oct-PD, and Pen-PMO, respectively, and their corresponding water contact angles were 45.5°, 44.3°, and 47.8°. Overall, Pen-PMO exhibited favorable transmittance and wettability, as well as the lowest surface tension, indicating the highest interfacial activity among the three compounds. These results demonstrate that optical properties, molecular polarity, and interfacial properties can be controlled by tuning hydrophobic tail topology and hydroxy functionality across glyceryl and monoalcohol ether architectures. Full article

Fraud in herbal medicines and botanical supplements—such as biological substitution, dilution with inert material, undeclared active pharmaceutical ingredients (APIs), and intentional mislabeling—represents a significant and underestimated threat to public health. Beyond regulatory problems, fraudulent botanical products also compromise the scientific integrity of bioactive compound research. If pharmacological or clinical studies are carried out on adulterated material without knowing it, the resulting data on safety and efficacy become unreliable, and any conclusions drawn from such data are questionable. This review critically evaluates multi-platform metabolomics as an analytical decision-making framework for botanical fraud detection. Rather than cataloging available methods, we focus on the complete analytical pipeline: study design and sample strategy, multi-platform fingerprint acquisition and processing (NMR, GC-MS, LC-HRMS, HPTLC), and chemometric modeling, validation, and decision support. Particular emphasis is placed on data fusion across platforms and the requirements for producing decision-grade evidence—analytical outputs robust enough to support market monitoring and regulatory action. Full article

Introduction: PKMYT1 is a WEE-family G2/M cell cycle checkpoint kinase commonly overexpressed in a broad spectrum of human malignancies. WEE1 exclusively phosphorylates CDK1 at Tyr15, whereas PKMYT1 targets both Thr14 and Tyr15. Unlike WEE1 inhibition, PKMYT1 suppression triggers synthetic lethality with CCNE1. Nearly all disclosed PKMYT1 inhibitors so far fall into structural analogs originating from RP-6306, making the discovery of PKMYT1 inhibitors with chemotypes distinct from RP-6306 crucial. Methods: The compounds were structurally optimized using CADD, synthesized, and characterized by ¹H NMR, ¹³C NMR, HRMS, and HPLC. They were then assessed for kinase binding affinity via the LanthaScreen^TM Eu kinase binding assay, for cellular activity using the CCK-8 assay, and for cell-cycle distribution by flow cytometry, along with investigations into related mechanisms. Results: This study yielded 24 compounds of 2-aminopyrimidine through substituent derivatization of the pyrimidine scaffold. Among these derivatives, MS13 exhibited potent kinase binding affinity against PKMYT1 (IC₅₀ = 0.86 nM) and demonstrated strong anti-proliferative activity against CCNE1 high-amplification OVCAR3 cells and HCC1569 cells (IC_50-OVCAR3 = 1.52 μM, IC_50-HCC1569 = 0.66 μM). Additionally, it showed some selectivity towards A549 and HEK293T cells, with SI values of 4.31 (A549/OVCAR3), 9.92 (A549/HCC1569), 2.04 (HEK293T/OVCAR3), and 4.70 (HEK293T/HCC1569). Compound MS13 dose-dependently suppressed clonogenicity and triggered S-phase cell cycle blockade. Pharmacokinetic studies showed moderate hepatic microsomal stability (t_1/2 = 32.2 min). Molecular dynamics simulations indicated a favorable binding mode between compound MS13 and PKMYT1 (docking score: −9.322 kcal/mol). Conclusions: MS13 is a promising highly potent tool compound that provides a clear direction for the future optimization of PKMYT1 inhibitors. Full article

Background/Objectives: Kidney transplantation remains the gold standard treatment of end-stage kidney disease; however, its recipients exhibit mixed clinical trajectories, with variable renal function and proteinuria evolution over time. Currently used methods to screen these changes are associated with possible adverse effects and limitations. Methods: In this single-center cohort study, 174 adult kidney transplant recipients were enrolled between January 2024 and January 2025 and followed for 12 months. Patients underwent serum and urinary metabolomic profiling using nuclear magnetic resonance (NMR) spectroscopy. Furthermore, clinical and biological data were collected, allowing for assessment of changes in renal function and proteinuria, with patient stratification based on outcome trends. Results: Serum metabolomic profiles were linked to renal outcomes. For ΔeGFR, valine differed between patients with positive and negative trajectories, while GlycA, GlycB and Glyc/SPC were associated with ΔeGFR in adjusted models. For Δproteinuria, GlycA, VLDL particles and triglycerides showed correlations, while glucose differed between patients with improving and worsening proteinuria. In adjusted models, isoleucine, alanine, GlycA and Glyc/SPC were associated with Δproteinuria. Urinary metabolomic profiles showed fewer associations. Dimethylamine and urinary creatinine were associated with ΔeGFR in adjusted models, while acetic acid differed between proteinuria groups. No urinary metabolite was associated with Δproteinuria after adjustment. Conclusions: Overall, metabolomic changes were connected with renal outcomes in kidney transplant patients, with distinct but partially overlapping patterns for ΔGFR and Δproteinuria. Serum findings were more consistent, while urinary associations were more limited. Further longitudinal and externally validated studies are required to confirm these observations and explore the potential of this metabolomic approach in the search for novel biomarkers. Full article

Ultrasonic-assisted heterogeneous Fenton-like (UHEF) pretreatment is an emerging strategy that overcomes the limitations of traditional homogeneous Fenton systems while enhancing the efficiency of lignocellulosic biomass processing. In this study, we constructed a UHEF system employing iron-loaded zeolite as a heterogeneous catalyst to pretreat eucalyptus sawdust (ES). Process conditions were optimized using response surface methodology (RSM) with a central composite design (CCD), yielding a maximum reducing sugar production of 441.45 mg/g. We systematically investigated the mechanism by which UHEF pretreatment enhances the enzymatic hydrolysis of ES through compositional analysis, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), cross-polarization magic-angle spinning carbon-13 nuclear magnetic resonance (CP/MAS ¹³C NMR), and scanning electron microscopy (SEM). Additionally, recovery and recycling experiments were conducted to evaluate the reusability of the iron-loaded zeolite. XRD, XPS, and ICP-OES were further used to verify the crystalline structure, surface Fe chemical states, and Fe loading of the catalyst, and Fe leaching was quantified for each reuse cycle. The results demonstrated that UHEF pretreatment effectively removed lignin and hemicellulose from ES, disrupted the cellulose crystalline structure, and generated numerous grooves on the substrate surface. These modifications increased the effective adsorption of cellulase and enhanced reducing sugar production to 4.32 times that of raw eucalyptus sawdust (RES). Although the recycling experiments indicated that the stability of the iron-loaded zeolite requires further improvement, the catalyst retained a certain degree of reusability over four consecutive cycles. These findings demonstrate that UHEF pretreatment is a promising approach with broad application prospects in lignocellulosic biorefinery, consistent with recent advances in advanced oxidation processes for biomass valorization. Full article

The accumulation of plastic waste has become a significant environmental challenge, stimulating the development of efficient recycling technologies capable of converting polymers into valuable products. In this study, polypropylene wastes were thermocatalytically converted into liquid hydrocarbons using three naturally occurring types of clay as catalysts, namely, kaolin, illite, and bentonite. The obtained liquid products were investigated using one- and two-dimensional NMR spectroscopy, including 1H, 13C, and COSY techniques. Quantitative evaluation of hydrocarbon group composition was performed using established NMR correlations to determine the content of paraffins, olefins and aromatic compounds as well as fuel-related parameters. The results demonstrated that paraffins were the predominant constituents in all pyrolysis oils, accounting for more than 70 vol.%, while olefins and aromatics were present in smaller amounts. Although all catalysts promoted the formation of liquid mixtures of hydrocarbon, noticeable differences in product composition were observed. Oil obtained over illite exhibited increased aromaticity and lower olefin content, whereas kaolin produced a product characterized by the highest isoparaffin index and estimated research octane number. The findings indicate that variations in catalysts influence the characteristics of polypropylene-derived oils and may be used to tailor products’ properties for their utilization as fuel additives or petrochemical feedstocks. Full article

4′-Hydroxymethoxychalcones represent structurally diverse chalcone derivatives that are attractive substrates for microbial functionalization; however, the impact of methoxy substitution position on their cascade biotransformation by fungi remains poorly understood. In this study, three regioisomeric 4′-hydroxymethoxychalcones, featuring ortho-, meta-, or para-methoxy groups on ring B, were transformed using eight entomopathogenic fungal strains belonging to the genera Beauveria, Isaria, and Metarhizium. Metabolic profiles were monitored over a 10-day period using ultra-high-performance liquid chromatography coupled with diode-array detection (UHPLC-DAD), and the structures of the major products were elucidated primarily by one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy and further supported by high-resolution electrospray ionization quadrupole time-of-flight mass spectrometry (HR-ESI-QTOF-MS). The investigated microorganisms catalyzed multistep transformations encompassing the reduction of the α,β-unsaturated carbonyl system, methylglucosylation, O-demethylation, and the formation of secondary polar metabolites. Although ene-reduction constituted the predominant initial reaction for all substrates, the relative distribution of subsequent metabolites varied depending on both the fungal strain and, to a lesser extent, the position of the methoxy group. The ortho-methoxy derivative exhibited the highest propensity for O-demethylation; the meta-substituted substrate generated the most heterogeneous secondary metabolite profiles, whereas the para-methoxy analogue showed the most consistent accumulation of methylglucosylated dihydrochalcones. These findings indicate that methoxy substitution position does not alter the common core biotransformation pathway, but can modulate the relative efficiency of individual steps and the extent of secondary metabolism. Full article

In this study, we developed two complementary synthetic routes to novel piperidine- and azetidine-containing 2,3-disubstituted propanoic acid derivatives as heterocyclic amino acid building blocks. The strategy employs ketone- and carboxylic acid-derived Meldrum’s acid intermediates, which are converted into common α,β-unsaturated methyl esters through methanolysis; they are subsequently diversified via DBU-promoted aza-Michael addition with saturated cyclic amines and aromatic NH-heterocycles. The ketone-derived approach provided piperidine-containing derivatives in 35–89% yield and the corresponding azetidine analogues in 61–92% yield, whereas the complementary acid-derived route afforded regioisomeric products in 59–85% and 61–89% yield, respectively. Both synthetic sequences tolerated a broad range of nitrogen nucleophiles, and no alternative regioisomeric aza-Michael products were detected for heterocycles containing multiple nitrogen atoms. The structures of the synthesized compounds were established via ¹H, ¹³C, ¹⁵N, and ¹⁹F NMR spectroscopy together with HRMS, including detailed multidimensional NMR analysis of representative products. The developed methodology provides efficient access to structurally diverse heterocyclic propanoic acid derivatives and expands the repertoire of amino acid building blocks available for peptide chemistry, medicinal chemistry, and DNA-encoded library synthesis. Full article

Gonadotropin-Releasing Hormone receptors (GnRHRs) are overexpressed in several hormone-dependent malignancies, making them attractive molecular targets for selective anticancer drug delivery. Peptide–drug conjugates (PDCs) are a promising therapy for cancer and autoimmune diseases with high specificity and reduced toxicity. In this study, the three-dimensional structures of two previously synthesized mitoxantrone–GnRH conjugates, con3 and con7, were elucidated using high-resolution NMR spectroscopy in combination with molecular dynamics (MD) simulations. Complete ¹H and ¹³C resonance assignments were achieved in DMSO-d₆ through two-dimensional NMR experiments. NOESY-derived distance restraints were subsequently used to refine the conformational ensembles obtained from MD simulations performed in water and DMSO. Both conjugates exhibited compact bent conformations with a U-shaped peptide backbone. The mitoxantrone moiety is positioned close to the peptide backbone in water simulations and NMR-refined structures, while it is positioned farther away in DMSO, without affecting the orientation of key residues involved in GnRH receptor binding. Importantly, His², Trp³, and Arg⁸ remain solvent-exposed, whereas the disulfide bond is easily accessible to the solvent, consistent with the proposed drug release mechanism by the thioredoxin system. NMR-restrained molecular modeling confirmed the dominant conformational features predicted by the unconstrained theoretical simulations. Overall, these findings provide better structural understanding of the molecular organization of mitoxantrone–GnRH conjugates, highlighting key receptor-recognition residues and supporting both the proposed thioredoxin-mediated drug release mechanism and their previously reported biological properties. These insights may facilitate the rational design and optimization of improved GnRH peptide–drug conjugates for targeted therapy. Full article

Ganoderma lucidum is a medicinal mushroom widely recognized as a source of bioactive metabolites, particularly triterpenoids. Although most studies have focused on fruiting bodies and spores, the potential of cultured mycelial biomass as a source of functional secondary metabolites remains less explored. In this study, we isolated and characterized polycarpol from the mycelia of G. lucidum and evaluated its anti-melanogenic activity in B16F10 murine melanoma cells. Dried mycelia obtained after liquid culture were extracted with 70% ethanol, partitioned with ethyl acetate, and purified by repeated chromatographic separation. The isolated compound was identified as polycarpol by LC–ESI–MS, HR-MS/MS, and NMR spectroscopy, together with comparison with previously reported spectroscopic data. The anti-melanogenic activity of polycarpol was evaluated in α-MSH-stimulated B16F10 murine melanoma cells, a commonly used cellular model of melanogenesis. Polycarpol reduced α-melanocyte-stimulating hormone-induced cellular tyrosinase activity and melanin production at concentrations that did not markedly affect cell viability. Notably, 2 μg/mL (4.54 μM) polycarpol showed a melanin-inhibitory effect comparable to that of arbutin. Western blot analysis showed that polycarpol decreased the expression of microphthalmia-associated transcription factor, tyrosinase, and tyrosinase-related protein-1. In addition, polycarpol suppressed CREB phosphorylation and modulated the MAPK signaling pathways. These findings suggest that polycarpol inhibits melanogenesis through regulation of MITF-associated melanogenic signaling. Overall, this study demonstrates that cultured G. lucidum mycelia can produce anti-melanogenic triterpenoids and highlights cultured mycelial biomass as a controllable fungal material for exploring anti-melanogenic triterpenoids, although further optimization is required to improve production efficiency. Full article