13C NMR Research Articles

Controlling the Mechanism of Nucleation and Growth Enables Synthesis of UiO‐66 Metal–Organic Framework with Desired Macroscopic Properties

AbstractBy combining in situ X‐ray diffraction, Zr K‐edge X‐ray absorption spectroscopy and 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, we show that the properties of the final MOF are influenced by H2O and HCl via affecting the nucleation and crystal growth at the molecular level. The nucleation implies hydrolysis of monomeric zirconium chloride complexes into zirconium‐oxo species, and this process is promoted by H2O and inhibited by HCl, allowing to control crystal size by adjusting H2O/Zr and HCl/Zr ratios. The rate‐determining step of crystal growth is represented by the condensation of monomeric and oligomeric zirconium‐oxo species into clusters, or nodes, with the structure identical to that in secondary building units (SBU) of UiO‐66 framework. The rapid crystallization in the absence of HCl leads to formation of defective secondary building units with missing zirconium atoms, providing a pathway to control the number of defects in UiO‐66 crystals. Remarkably, we have shown that assembling of the metal nodes and linkers into the UiO‐66 structure is not the rate‐limiting step, and the degree of deprotonation of the linker has no direct effect on the crystallization kinetics or crystal size of product.

MALDI-TOF Mass Spectrometry as the Tool for the Identification of Features of Polymers Obtained by Inverse Vulcanization

The MALDI-TOF mass-spectrometry was employed to analyze the structure of the reaction products of limonene, a natural terpene, and elemental sulfur, with the objective of identifying the occurrence of side processes, such as oxidative dehydrogenation, aromatization, and the Diels–Alder reaction cascade. The MALDI-TOF mass-spectrometry was demonstrated to be effective for the analysis of high-sulfur polymers obtained by the inverse vulcanization reaction, allowing for the unambiguous separation of sulfur-containing and hydrocarbon molecular fragments and the detailed characterization of macromolecular structures. By varying the ratio of sulfur (S8) and limonene in the initial reaction system, we were able to ascertain the limiting amount of sulfur that can be covalently bonded by terpene, as well as determine the average length of polysulfide chains under the assumption of equal reactivity and complete depletion of all double bonds. The side reaction of limonene aromatization, as indicated by the MALDI-TOF spectrum of the product resulting from its interaction with elemental sulfur, was corroborated by 1H and 13C NMR spectroscopy. Consequently, the registration and interpretation of MALDI-TOF spectra of inverse vulcanization products, either independently or in conjunction with the application of 1H and 13C NMR spectroscopy methods, as well as the determination of the limiting number of sulfur atoms that can be bound to one molecule of an unsaturated compound, paves the way for new avenues of investigation into the structure and side reactions involved in the synthesis of high-sulfur polymers.

Cp2TiCl2-Catalyzed Interaction of Methylenecycloalkane with BF3·THF

The Cp2TiCl2-catalyzed interaction of methylenecycloalkanes with BF3·THF in tetrahydrofuran was carried out for the first time with the formation of target 1-fluoro-1-boraspirocarbocycles and also isomerization products of a starting monomer (1-methylcycloalk-1-enes). The structure of reaction products was elucidated using one- (1H, 13C Dept, 11B, 19F) and two-dimensional (COSY, HSQC, HMBC) NMR spectroscopy, mass spectrometry combined with quantum-chemical calculations of 13C NMR chemical shifts.

New insights into transreaction mechanism between poly (ethylene terephthalate) and bisphenol A polycarbonate in melt

AbstractIn the present study, the macromolecular chain composition of copolymers prepared by the reactive blending of poly(ethylene terephthalate) (PET) and bisphenol A polycarbonate (PC) in the presence of Ti(OBu)4 catalyst was tested using 1H and 13C NMR spectroscopy. The NMR spectra were meticulously analyzed across all regions, revealing unexpected results that provide new insights into the transreaction mechanism occurring between these two polymers in the melt phase. It was found that only two primary reactions occurred: the formation of a bisphenol A terephthalate bond accompanied by the release of ethylene carbonate and the formation of an aliphatic–aromatic ether bond with the release of CO2. The release of ethylene carbonate during the PET‐PC blending led to a loss of ethylene glycol (EG). The kinetics of EG loss and ether bond formation were examined. A new transreaction mechanism for PET‐PC reactive blending is proposed. © 2024 Society of Chemical Industry.

Unexpected Magnetic Moments in Manganese-Doped (CdSe)13 Nanoclusters: Role of Ligands.

This study explores the enhancement in magnetic and photoluminescence properties of Mn2+-doped (CdSe)13 nanoclusters, significantly influenced by the introduction of paramagnetic centers through doping, facilitated by optimized precursor chemistry and precisely controlled surface ligand interactions. Using a cost-effective and scalable synthesis approach with elemental Se and NaBH4 (Se-NaBH4) in n-octylamine, we tailored bonding configurations (Cd-O, Cd-N, and Cd-Se) on the surface of nanoclusters, as confirmed by EXAFS analysis. These bonding configurations allowed for tunable Mn2+-doping with tetrahedral coordination, further stabilized by hydrogen-bonded acetate ligands, as evidenced by 13C NMR and IR spectroscopy. Mulliken charge analysis indicates that the charge redistribution on Se2- suggests electron transfer between surface ligands and the nanocluster, contributing to spin fluctuations. These tailored configurations markedly increased the nanoclusters' magnetic susceptibility and photoluminescence efficiency. The resulting nanoclusters demonstrated a clear concentration-dependent response in emission lifetimes and intensities upon exposure to magnetic field effects (MFE) and spin-spin coupling, alongside a large magnetic moment exceeding 40 μB at 180K. These findings highlight the potential of these nanoclusters for magneto-optical devices and spintronic applications, showcasing their tunable magnetic properties and exciton dynamics.

1,1-Bis(4-hydroxyphenyl)-2-ferrocenylbutane

Ferrociphenols are anticancer organometallic molecules bearing a ferrocene group linked, at least, to one para-phenol moiety via a double bond. Up to the present, their biological activity has been thought to be linked to their oxidation within cells to form a reactive quinone-methide metabolite with the participation of this central double bond. To prove this assertion, the alkenyl entity of ferrociphenol 1a (1,1-bis-(4-hydroxyphenyl)-2-ferrocenylbut-1-ene) was reduced by triethylsilane in an acidic medium to obtain the alkyl counterpart 1,1-bis(4-hydrophenyl)-2-ferrocenylbutane. 1,1-bis(4-hydrophenyl)-2-ferrocenylbutane was fully characterized by 1H NMR (including COSY), 13C NMR, HRMS, IR, elemental analysis and X-ray diffraction (XRD). Although missing the central double bond, this compound remains biologically active, opening the way to a new family of anticancer ferrocene-containing molecules.

Unexpected Magnetic Moments in Manganese‐Doped (CdSe)13 Nanoclusters: Role of Ligands

This study explores the enhancement in magnetic and photoluminescence properties of Mn2+‐doped (CdSe)13 nanoclusters, significantly influenced by the introduction of paramagnetic centers through doping, facilitated by optimized precursor chemistry and precisely controlled surface ligand interactions. Using a cost‐effective and scalable synthesis approach with elemental Se and NaBH4 (Se‐NaBH4) in n‐octylamine, we tailored bonding configurations (Cd‐O, Cd‐N, and Cd‐Se) on the surface of nanoclusters, as confirmed by EXAFS analysis. These bonding configurations allowed for tunable Mn2+‐doping with tetrahedral coordination, further stabilized by hydrogen‐bonded acetate ligands, as evidenced by 13C NMR and IR spectroscopy. Mulliken charge analysis indicates that the charge redistribution on Se2‐ suggests electron transfer between surface ligands and the nanocluster, contributing to spin fluctuations. These tailored configurations markedly increased the nanoclusters' magnetic susceptibility and photoluminescence efficiency. The resulting nanoclusters demonstrated a clear concentration‐dependent response in emission lifetimes and intensities upon exposure to magnetic field effects (MFE) and spin‐spin coupling, alongside a large magnetic moment exceeding 40 μB at 180K. These findings highlight the potential of these nanoclusters for magneto‐optical devices and spintronic applications, showcasing their tunable magnetic properties and exciton dynamics.

Discovery and Chemical Exploration of Spiro[Benzofuran-3,3'-Pyrroles] Derivatives as Innovative FLT3 Inhibitors for Targeting Acute Myeloid Leukemia.

This study aimed at the synthesis of several spiro[benzofuran-3,3'-pyrroles] derivatives by a three-component reaction conducted by mixing DMAD, N-bridgehead het-erocycles, and benzofuran-2,3-diones in dichloromethane at room temperature for 24 h. Moreover, in vitro evaluation of their cytotoxicity affinities against FMS-like tyrosine kinase 3 was carried out. The objective of this study was to use a one-pot, three-component reaction to synthesize a novel set of spiro[benzofuran-3,3'-pyrroles] derivatives. A novel set of spiro[benzofuran-3,3'-pyrroles] ((11-13)a-e) was synthesized by a one-pot three-component reaction involving dimethyl acetylenedicarboxylate, N-bridgehead heterocycles and benzofuran-2,3-diones in dichloromethane at room temperature for 24 h. The compounds were analyzed using NMR 1H, 13C, 2D-NMR (COSY, HMQC, HMBC), and HRMS. Docking simulations were conducted to elucidate the anticancer activity of synthe-sized compounds on FLT3 protein, with Gilteritinib as a reference for comparison. This study demonstrated the successful design, synthesis, and biological evaluation of spiro[benzofuran-3,3'-pyrroles] derivatives as FLT3 inhibitors for AML treatment. The synthesized compounds demonstrated promising binding affinities and significant inhibitory activity against FLT3 kinase. The inhibitors (11a, 11b, 11c, 12d, and 12e) exhibited excellent selectivity profiles against FLT3. Particularly, compound 12e showed strong binding affinity and potent inhibitory activity (IC50 = 2.5 μM). Fifteen new synthetic spiro[benzofuran-3,3'-pyrroles] were prepared, character-ized, and evaluated for cytotoxicity affinities against FMS-like tyrosine kinase 3. Compound 12e showed strong binding affinity and potent inhibitory activity (IC50 = 2.5 μM), making it a promising candidate for further development as a therapeutic option for AML treatment. These findings lay the groundwork for further optimization and development of spiro[benzo-furan-3,3'-pyrroles] derivatives as potential therapeutics for AML treatment. Further studies are needed to explore their efficacy and safety profiles in preclinical and clinical settings.

Boosting 1H and 13C NMR signals by orders of magnitude on a bench.

Sensitivity is often the Achilles' heel of liquid-state nuclear magnetic resonance (NMR) experiments. This problem is perhaps most pressing at the lowest fields (e.g., 80-MHz 1H frequency), with rapidly increasing access to NMR through benchtop systems, but also sometimes for higher-field NMR systems from 300 MHz to 1.2 GHz. Hyperpolarization by dissolution dynamic nuclear polarization (dDNP) can address this sensitivity limitation. However, dDNP implies massive and complex cryogenic and high-field instrumentation, which cannot be installed on the bench. We introduce here a compact helium-free 1-T tabletop polarizer as a simple and low-cost alternative. After freezing and polarizing the frozen analyte solutions at 77 K, we demonstrate 1H signal enhancement factors of 100, with rapid 1-s buildup times. The high polarization is subsequently transferred by 1H→13C cross polarization (CP) to 13C spins. Such a simple benchtop polarizer, in combination with hyperpolarizing solid matrices (HYPSOs), may open the way to replenishable hyperpolarization throughout multiple liquid-state NMR experiments.

Design, synthesis, X-ray crystal structure, and antifungal evaluation of new acetohydrazide derivatives containing a 4-thioquinazoline moiety.

To find efficient agricultural fungicides, 29 new 4-thioquinazoline-containing acetohydrazide derivatives were prepared and tested for their fungicidal properties. All of the target compounds were characterized by 1H and 13C nuclear magnetic resonance and high-resolution mass spectrometry techniques, and the molecular structure of compound A2 was verified by single-crystal X-ray diffraction measurement. The experimental results revealed that many compounds from this series had impressive inhibition efficacies in vitro against the tested fungi. For example, compound A25 was identified as the best fungicidal agent against Rhizoctonia solani with an EC50 (half-maximal effective concentration) value of 0.66 μg mL-1, superior to those of the commercial fungicides chlorothalonil, carbendazim and boscalid. Additionally, this compound displayed favorable protection and curative activities in vivo against rice sheath blight caused by R. solani. Antifungal mechanistic studies on compound A25 indicated that this compound exerted its strong anti-R. solani effects probably through an effective inhibition of fungal succinate dehydrogenase activity [half-maximal inhibitory concentration (IC50) = 4.88 μm] and the impairment of cell membrane integrity, based on the results from enzymatic bioassays, molecular docking studies, and scanning and transmission electron microscopy observations. Acetohydrazide derivatives containing the 4-thioquinazoline moiety had the potential to be employed as lead compounds for developing more efficient agricultural fungicides in the near future. © 2024 Society of Chemical Industry.

Synthesis, characterization, biodegradation, and evaluation of the surface‐active properties of non‐ionic gemini surfactants derived from lauryl diethanolamide

AbstractThe surface activities and application properties of aqueous solution surfactants are greatly influenced by their structure, especially the spacer group that connects the polar head groups. Herein, four new non‐ionic Gemini surfactants with different spacers were designed and synthesized, and their surfactant properties and biodegradability were studied. The synthesis of these compounds involves a two‐step procedure. The first step is the formation of an amide from lauric acid and diethanolamine. The second step is the reaction of lauryl diethanolamide with four different spacers, the latter being flexible‐hydrophilic, and rigid‐hydrophobic in structure, respectively. Their structures were characterized using 1H NMR, 13C NMR, FT‐IR, and ESI‐MS. The critical micelle concentration (CMC), the surface tension at CMC (γCMC), the efficiency of these compounds to reduce the surface tension by 20 mN/m (C20 and pC20), the effectiveness (πCMC), the maximum surface excess (Γmax), and the minimum surface area (Amin) were measured at 20, 40, and 50°C. The molecular architecture of the spacers in these compounds strongly influences the thermodynamic parameters, such as the standard change for Gibbs free energy of adsorption (ΔG°ads) and the standard change for Gibbs free energy of micellization (ΔG°mic). The ability of these surfactants to reduce surface tension is particularly good, but their distinguishing characteristic is their high relative propensity to form micellar aggregates. This aggregation ability improves as the hydrophilicity and flexibility of the spacer increase. Finally, in less than 30 days, all non‐ionic Gemini surfactants were determined to be 99% biodegradable in river water.

Multicomponent Synthesis of 2,4,5-Trisubstituted Thiazoles Using a Sustainable Carbonaceous Catalyst and Assessment of Its Herbicidal and Antibacterial Potential.

Herein, a novel, biocatalyzed, and on-water microwave-assisted multicomponent methodology have been developed for the synthesis of trisubstituted thiazoles (4a-4v). The reaction was catalyzed using a sulfonated peanut shell residue-derived carbonaceous catalyst (SPWB). The developed catalyst was characterized using Fourier transform infrared (FTIR), a Brunauer-Emmett-Teller (BET) surface area analyzer, a field emission scanning electron microscope (FE-SEM), energy-dispersive X-ray (EDX), and a particle size analyzer (PSA). The acidic sites have been established using acid-base back-titration methods. The molecular structures of all the synthesized compounds were validated using FT-IR, 1H NMR, 13C NMR, elemental, and HRMS analyses. Herbicidal potential was evaluated by using Raphanus sativus L. as a model. Furthermore, the antibacterial potential of thiazoles was evaluated against Staphylococcus aureus, Bacillus subtilis, Xanthomonas campestris, Escherichia coli, Micrococcus luteus, and Pseudomonas aeruginosa bacterial strains. The compound 4r displayed improved seed growth inhibition in Raphanus sativus L. versus a commercially available herbicide, i.e., pendimethalin. The antibacterial activity was promising against bacterial strains (MIC: 4-64 μg/mL). The compound 4r was the most potent against P. aeruginosa and S. aureus (MIC: 0.0076 μM) versus standard drug streptomycin (MIC: 0.0138 μM). Moreover, in silico studies performed with the most effective compound 4r against P. aeruginosa revealed its potential binding mode within the protein binding pocket. The biological data revealed compound 4r as a potential candidate for the development of potent herbicidal and antibacterial agents. In a nutshell, this study offers peanut shell biowaste to be a sustainable biomass for heterogeneous acid catalyst preparation and its application in the multicomponent synthesis of bioactive thiazoles, accommodating the concept of sustainable development goals and circular bioeconomy.

Design and Synthesis of Novel Spiro [Chromane‐2,4′‐Piperidin]‐4‐One Derivatives: Anti‐Proliferative Investigation and Molecular Docking Studies

AbstractChemists around the globe are extensively working for remedial solutions to cancer, one of the greatest health hazards. We have synthesized twenty‐three novel spiro [chromane‐2,4′‐piperidin]‐ 4 ‐one derivatives (KBS and KMS series of analogues) as part of our ongoing research to combat this deadly disease, and confirmed their structures using 1H NMR, 13C NMR, HRMS, and FT‐IR. Furthermore, we employed single‐crystal XRD to identify the compound structures of KBS4 and KMS10. We have tested the compounds on the cell line such as MCF‐7; U87‐MG; SCC‐25; and HEK‐293T, via WST‐1 assay. Eight compounds showed IC50 values ranging 3.9–10 μM; against the cell line MCF‐7. The best compounds of all were KMS9 (IC50=3.83 μM), KMS5 (IC50=4.14 μM), and KBS8 (IC50=8.24 μM), which promoted apoptosis in MCF‐7 cells. KMS5 and KMS9 compounds showed G1 cell cycle arrest, while compound KBS8 showed G2 cell cycle arrest. Insilco ADME studies were carried out. Molecular docking and dynamics experiments showed how KMS5, KMS9, and KBS8 bind to the active region of the EGFR family – a group of receptor tyrosine kinase (RTK) proteins (PDB ID: 7JXP, 2.16 Å). Further structural modifications of the KMS5, KMS9, and KBS8 may improve their activity against breast cancer.

Design, synthesis, and antifungal activity of hydrazone Schiff bases containing cinnamaldehyde moieties

In order to further find compounds with antifungal activities, a series of Schiff bases containing cinnamaldehyde moieties were designed and synthesized by using the principle of active group splicing. All compounds were identified by 1H NMR, 13C NMR and HRMS. The results of antifungal activity showed that the antifungal activities of 22 against 8 tested fungi were all more than 80 % at 50 μg/mL, and the EC50 value of 22 against P. oryza was 4.3 μg/mL, which was only 12 % of the positive control thiabendazole. Scanning electron microscopy showed that compound 22 caused obvious damage to the mycelia of P. oryza.

Enhancing pectin's antioxidant properties through ferulic acid grafting: Application in olive oil‐in‐water emulsion

AbstractIn order to improve pectin antioxidant properties and enlarge the field of its potential applications, ferulic acid grafted pectin conjugates (PE‐g‐FA) were prepared using laccase as the catalyst at 30°C in an aqueous medium. The structures of PE‐g‐FA were characterized using UV–vis, FTIR, and NMR (1H and 13C). In addition, the antioxidant activity of PE‐g‐FA was evaluated according to the DPPH and ABTS free radical scavenging ability. Olive oil in water emulsions, containing emulsifiers WPI and PE‐g‐FA, were assessed for their physical and oxidative stability through particle size, zeta‐potential, peroxide value (POV), and 2‐thiobarbituric acid reactive substance (TBARS) formation. The results indicated that the formation of covalent bonds between the pectin carboxymethyl groups and FA hydroxyl group. The determination of the total phenolic content showed that PE‐g‐FA contained seven times more polyphenols than native PE. DPPH and ABTS free radical scavenging rate of 0.5HMP‐g‐FA were increased by 56.83% and 18.90% compared with HMP, respectively. In addition, the emulsion stabilized by WPI and 0.5HMP‐g‐FA showed smallest and uniform average particle size (855.9 ± 51.13 nm) on the 1st day. Although its POV value was slightly higher than that of emulsion stabilized by WPI and HMP, it was much lower than that of control groups. Overall, these results have important implications for enzymatic modification of pectin to obtain high antioxidant products and their application in pectin‐based emulsions.

Bioguided isolation and identification of the protodioscin isomers from Brachiaria ruziziensis L. as inhibitors of growth of Euphorbia heterophylla L.

A bioguided identification of the phytotoxic compounds of the Brachiaria ruziziensis L. on the weed species Euphorbia heterophylla L. was conducted. From the butanolic fraction of B. ruziziensis it was separated an active subfraction (Subfraction III) that was demonstrated to contain the steroidal saponins. These substances were determined as protodioscin and protonedioscin by 1H and 13C NMR analysis. b-ethyl glucose was also identified, but it represented only 2.4% of the subfraction III. The effects of pure protodioscin were very similar to those caused by Fraction III or saponins isolated from B. ruziziensis. Root length was the most sensitive variable and the germination indices were little modified. The calculated ID50 for primary root inhibition was 390.1 ± 112.7 µg/ml and 359.5 ± 44.6 µg/ml for saponins and pure protodioscin, respectively. b-ethyl glucose did not cause significant modifications in the germination and seedling growth when assayed at a concentration range of 100 to 1000 µg/ml. These results suggest that protodioscin isomers are the causative compounds of the inhibitory effects on growth of E. heterophylla. These compounds are possibly involved in the reported ability of B. ruziziensis in reducing the emergence and the growth of weed species when used as a cover plants. This finding confirms the potential of the utilization of B. ruziziensis for weed management options in the field.

An efficient synthesis of some new bipyrazole derivatives by three-component reaction between 3-methyl-1H-pyrazol-4(5H)-one, aroylphenylhydrazones and arylglyoxals

A simple one-pot and catalyst-free method is reported for synthesis of some new bipyrazole derivatives by three-component reaction between arylglyoxals, 3-methyl-1H-pyrazol-4(5H)-one and aroylphenylhydrazone derivatives. The reactions were carried out in ethanol as a green solvent in neutral reaction conditions and products were simply isolated by filtering of the precipitated solids in high yields. All products were characterized by their 1H and 13C NMR and IR spectral and elemental analysis data.

New Bis 4-Bromobenzene Sulphonate Compound: Synthesis, Characterizaton, DFT study, Antibacterial and Leishmanicidal activity

The new bis 4-bromobenzene sulphonate compound called as ((1E,1'E)-(1,4-phenylenebis(azanylylidene))bis(methanylylidene))bis(4,1-phenylene) bis(4-bromobenzenesulfonate) (I) was synthesized. Fourier transform infrared (FTIR), proton and carbon-13 nuclear magnetic resonance (1H- and 13C-NMR) methods were used to confirm the molecular structure. All calculations were performed at DFT/B3LYP/6-311G(d,p) level. IR and NMR spectral data were compared with experimental ones and the details of molecular structure were investigated. The antimicrobial activity of the synthesized compound (I) was determined by Alamar blue microdilution method against seven different established standard bacteria and one parasite isolate. The compound I exhibited antibacterial activity at different concentrations. Compound I was found to have antimicrobial activity on all bacterial species and L. infantum parasite, albeit at different concentrations. Compound I has the most effective antibacterial activity on S. flexneri and the least effect on S. aureus and E. cloacea bacteria. In order for the synthesized compound to be used as a drug candidate, in vivo control studies in a series of experimental animal models and whether it has toxic effects on human cells should be tested. In silico analysis was conducted on four different proteins using the synthesized compound I to investigate the essential interactions responsible for its antibacterial activity. The docking results of compound I supported its antibacterial activity, revealing high inhibition constants.

Synthesis of Chalcones, Screening In silico and In vitro and Evaluation of Helicobacter pylori Adhesion by Molecular Docking.

We synthetized 10 hydroxylated and methoxylated chalcones and evaluated them targeting MMP-9 inhibition, looking for the rate of adhesion of H. pylori in gastric cells, and then, reduction of the inflammatory response as alternative therapeutic agents for controlling the infection. Helicobacter pylori is a Gram-negative bacterium that chronically infects the human stomach, a risk factor for the development of inflammatory gastrointestinal diseases, including cancer, and is classified as a group I carcinogen. It is estimated that it infects around 45% of the global population and that the persistence of the infection is related to the adhesion of the bacteria in the gastric epithelium. The progression of gastric lesions to cancer is connected to the activation of the NF-κB and MAPK pathways, especially in cagA+ strains, which are related to increased expression of MMP-9. The activation of these metalloproteinases (MMPs) contributes to the adhesion of the bacterium in gastric cells and the evolving stages of cancer, such as enabling metastasis. Due to the increasing resistance to the current therapy protocols, the search for alternative targets and candidate molecules is necessary. In this way, controlling adhesion seems to be a suitable option since it is a crucial step in the installation of the bacterium in the gastric environment. Synthetize ten hydroxylated and methoxylated chalcones. Assess their anti-H. pylori potential, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). Evaluate their cytotoxicity in AGS cells and selectivity with L-929 cells. Analyze the results and correlate them with in silico predictions to evaluate potential anti-adhesive properties for the chalcones against H. pylori. The chalcones were synthetized by Claisen-Schmidt condensation using Ba(OH)2 or LiOH as catalysts. Predictive in silico assays in PASS Online, tanimoto similarity, ADME properties and molecular docking in MMP-9 (PDB code: 6ESM) were performed. The in vitro assays carried out were the cell viability in gastric adenocarcinoma cells (AGS) and fibroblasts (L-929) by the MMT method and anti-H. pylori, by the broth microdilution method, through the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Ten chalcones were synthesized through Claisen-Schimdt condensation with yields of 10 to 52% and characterized by 1H and 13C nuclear magnetic resonance (NMR) and mass spectrometry (MS). in silico data revealed the possibility of anti-H. pylori, anti-inflammatory, and MMP-9 inhibition for the chalcones. Chalcone 9 showed the best growth inhibition values for MIC and MBC, at 1 μg/mL and 2 μg/mL, respectively. Chalcones 14 and 15 likewise demonstrated excellent inhibitory results, being 2 μg/mL for both MIC and MBC. Additionally, 15 had the best MMP-9 inhibition score. Despite not corroborating the in silico findings, chalcones 10, 13, and 18 showed good cytotoxicity and the best selectivity indices. All compounds exhibited strong activity against H. pylori, specially 15. The predicted MMP-9 inhibition by molecular docking added to the reasonable SI and CI50 values for 15 and the satisfactory reduction in the rate of survival of the bacteria, reveals that it may be acting synergically to reduce the inflammatory response and the possibilities for developing a tumor by inhibiting both bacteria and malignant cells.

Advancing photocatalytic performance for enhanced visible-light-driven H2 evolution and Cr (VI) reduction of g-C3N4 through defect engineering via electron beam irradiation

Defect engineering has emerged as a strategic approach for optimizing photocatalyst band structures to improve performance. High-energy electron-beam irradiation is a promising method for inducing vacancies and defects in semiconductor materials, providing a rapid and efficient solution. In this study, we used simple electron-beam irradiation to modify g-C3N4 photocatalysts, resulting in the rapid formation of nitrogen vacancies within the material. Characterization techniques such as 13C-nuclear magnetic resonance, X-ray photoelectron spectroscopy, and electron paramagnetic resonance confirmed the formation of nitrogen vacancies, resulting in an asymmetric charge distribution within the g-C3N4 crystal structure. The optimized photocatalyst, gCN-300, exhibited remarkable performance, producing hydrogen at a rate of 750.57 ± 9.9 μmol g-1h−1 and reducing Cr (VI) by 83.5 % within 2 h with long-term photostability. The improved performance was attributed to increased visible-light absorption, a greater number of surface-active sites, improved electronic conductivity, and efficient charge transfer. These factors were supported by UV–visible diffuse reflectance spectroscopy, photoluminescence, and photoelectrochemical analysis. Thus, this study demonstrates the effectiveness of electron-beam irradiation in the large-scale production of defect-engineered photocatalysts with high performance.