Nuclear Magnetic Spectroscopy Research Articles

Synthesis, characterization, and antibacterial studies of some of first transition series metals and zinc complexes with mixed ligands of trimethoprim-isatin and nitrogen base

Complexes of mixed-ligand Schiff bases [trimetho-prim (TMP) with isatin] (L1) and nitrogen bases [2,2′-bipyridine (bipy)] (L2), [1,10-phenanthroline (phen) (L3)] with metal chlorides: M = Cr3+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+ were prepared and characterized by metal content determination (%), FT-IR, electronic, nuclear magnetic resonance, mass spectroscopy, magnetic susceptibility, conductance measurements and elemental analysis (CHN). The bacterial activity of the ligands and their metal compounds was evaluated via various microorganisms. Infrared spectra of Schiff base showed an azomethine peak shifted in complexes that coincide synthesis and coordination of Schiff base through the nitrogen atom of azomethine C=N) and the oxygen atom of the carbonyl group of L1 with metal ions. L2, L3 (bipy, phen) coordinated through the di imine nitrogen atoms. Conductance dimensions suggested the non-conductance nature of all the compounds except Cr(III) complexes, this outcome fits in with the molar conductance value estimated for 1:1 electrolyte in DMF. Magnetic susceptibility analysis and electronic spectra indicated an octahedral geometry for all complexes. Biological study for prepared compounds have been evaluated towards pathogenic microbes Staphylococcus aureus and Bacillus subtilis. Some compounds have stronger antibacterial action than Schiff base towards tested microbes. KEY WORDS: Antimicrobial, Heterocyclic compounds, Schiff base, Trimethoprim drug, 2,2-Bipyridyl, 1,10-Phenanthroline Bull. Chem. Soc. Ethiop. 2024, 38(4), 1013-1025. DOI: https://dx.doi.org/10.4314/bcse.v38i4.16

Room-temperature stable Perillaldehyde—Natural cyclodextrin inclusion complexes: Preparation, characterization, thermal stability, water solubility, antioxidant activity and slow–release performance

The compound Perillaldehyde (PA) is a bioactive constituent found in natural Perilla oil, exhibiting remarkable antibacterial and antioxidant activity. However, the instability of this compound caused by the easy oxidation of its aldehyde and olefin groups imposes limitations on its extensive applications. Therefore, it is crucial to develop effective strategies for enhancing the stability of PA. This study focuses on utilizing a series of natural cyclodextrins (CDs) to synthesize inclusion complexes (ICs) with PA, aiming to improve water solubility and achieve exceptional stability at room temperature, which is essential for their potential applications in biomedicine or food industries. The hydrophobic cavity of CDs can accommodate the hexatomic ring and hydrophobic chains of PA based on the well-known size-matching effect and hydrophobic interaction, thereby forming stable ICs. Additionally, the hydrophilic outer wall of CDs imparts excellent water solubility to ICs. Phase solubility investigations demonstrate successful construction of α-CD-PA IC and β-CD-PA IC with an inclusion ratio of 1:1. Their respective stability constant (KC) are determined as 342 L/mol and 180 L/mol, indicating superior stability for α-CD-PA IC compared to β-CD-PA IC. Conversely, γ-CD with a larger cavity fails to form a stable inclusion complex with PA due to inadequate size matching. Nuclear Magnetic Resonance Hydrogen Spectroscopy (1H and 2D NMR) studies reveal that PA enters the CDs cavity (α-CD or β-CD) from its wide rim with almost the entire molecule being obliquely embedded within it. Thermogravimetry Analysis (TGA) confirm that after inclusion with CDs, PA exhibits expected stability at 25 ℃. Furthermore, CDs-PA ICs demonstrate significantly improved water solubility compared to pure PA along with enhanced antioxidant activity and slow-release performance, rendering them highly favorable for various applications.

Economically competitive Organic Acid‐Base mixtures as Catalysts for the Self‐Condensation of Diols into Polyethers

Organocatalysts are used in a wide range of polymerisation reactions with the advantage of being often more benign or sustainable, while maintaining high catalytic activity. However, the low thermal stability of most of these compounds remain an obstacle for high temperature reactions. It was recently reported that complexes formed from a base such 1,4,7‐triazabicyclodecene (TBD) and an acid such as methane sulfonic acid (MSA) demonstrate high thermal stability while efficiently catalysing polycondensation reactions. However, TBD is not cost‐efficient neither available at industrial scale, which makes it unfit for scaling up. Herein, eight different bases have been investigated as to replace TBD. First, we confirm the complex formation between the MSA and the bases by nuclear magnetic spectroscopy while confirming the thermal stability of the mixtures by thermogravimetric analysis before evaluating of their catalytic activity in the self‐condensation of 1,6hexanediol. Among the different investigated bases, 1,1,3,3‐tetramethyl guanidine (TMG) appeared to be the best option since it gathers both high thermal resistance and good catalytic activity. These characteristics make TMG suitable for replacing TBD in the self‐condensation of diols while opening the way for being used in a wide range of high temperature (de)polymerisation reactions.

Anti‐Biofilm and Anti‐Virulence Potential of 2‐Amino‐1,3,4‐Thiadiazole Derivatives

AbstractBiofilms are microbial communities that facilitate the pathogenesis of life‐threatening microbial infections through the glazing of mucosal surfaces or implanted devices thus protecting them from medications and increasing mortality rates. To discover a new class of antibiofilm agents 2‐amino‐1,3,4 thiadiazoles hybridized with pharmacologically active heterocycles were designed and synthesized. The compounds were characterized by infrared, nuclear magnetic resonance, mass spectroscopy and elemental analysis. All the compounds were assessed for their anti‐biofilm and anti‐virulence activity against P. aeruginosa and S. aureus. Quinoline‐substituted thiadiazoles were found to possess potent anti‐biofilm activity against P. aeruginosa and S. aureus. The molecular docking analysis further confirms the antibiofilm potential of the compounds. Density functional theory studies were carried out to investigate the electronic and molecular properties of the most active hybrids.

Hydrothermal carbonization of two-phase olive mill waste (alperujo): Effect of aqueous phase recycling

Hydrothermal carbonization (HTC) is a promising technique for the conversion of lignocellulosic biomass, such as two-phase olive mill waste (TPOMW). However, the resulting generated aqueous phase (AP) rich in organic compounds is harmful if directly discharged in the environment. In this work, the use of recycled aqueous phase from the HTC process of TPOMW is evaluated as a reactive medium. The evolution of products yields, quality, morphology chemical structure, and composition with AP recycling runs are investigated by different analytical methods (Nuclear Magnetic Spectroscopy 1H and solid state 13C, Scanning Electron Microscopy, Elemental analysis, Proximate analysis, Fourier Infrared Transform spectroscopy, Total organic carbon, and total nitrogen). The results revealed significant improvement in the hydrochar yield and energy yield that increase 47.4 wt% to 53.0 wt% and 72.8%–81.3%, respectively. The increase in the number of recycling experiments promotes the lignin condensation as well as the polymerization of AP intermediates into microspheres. These phenomena lead to the increase in hydrochar yield as well as the modification of its micro-surface into a smooth porous surface through the recycling runs. Additionally, FT-IR and the solid state 13C NMR analysis demonstrated that AP recycling has no noticeable effect on the chemical structure of the produced hydrochars. Further analysis of the AP demonstrated that the total organic carbon and total nitrogen increase significantly after the first recycling run from 17.3 to 26.5 g/L and 0.4–0.6 g/L, respectively. The 1H NMR analysis revealed that AP is mainly formed by aliphatic and aromatic compounds.

Exploring the effects of the dietary fiber compound mediated by a longevity dietary pattern on antioxidation, characteristic bacterial genera, and metabolites based on fecal metabolomics

BackgroundAge-related dysbiosis of the microbiota has been linked to various negative health outcomes. This study aims to investigate the effects of a newly discovered dietary fiber compound (DFC) on aging, intestinal microbiota, and related metabolic processes. The DFC was identified through in vitro fermentation screening experiments, and its dosage and composition were determined based on a longevity dietary pattern.MethodsAged SPF C57BL/6 J mice (65 weeks old) and young mice (8 weeks old) were divided into three groups: a subgroup without dietary fiber (NDF), a low DFC dose subgroup (LDF, 10% DFC), and a high DFC dose subgroup (HDF, 20% DFC). The total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD) activity, malondialdehyde (MDA) content, and glutathione peroxidase (GSH-Px) activity in liver and serum samples of the mice were measured according to the manufacturer’s protocol. The expression levels of characteristic bacterial genera and fecal metabolite concentrations in mice were determined using quantitative real-time PCR (qPCR) and nuclear magnetic resonance hydrogen spectroscopy (1H NMR). Metabolomics analysis was further conducted to identify biological functions and potential pathways related to aging.ResultsAfter an 8-weeks dietary intervention, DFC supplementation significantly attenuated age-related weight loss, organ degeneration, and oxidative stress. And promoted the growth of Lactobacillus and Bifidobacterium and inhibited the growth of Escherichia coli (E. coli) and Bacteroides (p < 0.05) in the intestinal tracts of aged mice. Metabolomic analysis identified glycolipid and amino acid metabolic pathway biomarkers associated with aging that were differentially regulated by DFC consumption. Correlation analysis between the identified microbial flora and the biomarkers revealed potential mechanistic links between altered microbial composition and metabolic activity with aging markers.ConclusionsIn conclusion, this study revealed an important mechanism by which DFC consumption impacts healthspan and longevity, shedding light on optimizing dietary fiber or developing fiber-based interventions to improve human health.

Longitudinal trajectories of plasma polyunsaturated fatty acids and associations with psychosis-spectrum outcomes in early adulthood

Evidence supports associations between polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA) and psychosis. However, PUFA trajectories in the general population have not been characterised and associations with psychosis-spectrum outcomes in early adulthood are unknown. background METHODS: Plasma omega-6:omega-3 ratio and DHA %total fatty acids were measured by nuclear magnetic spectroscopy at 7,15,17 and 24years in the Avon Longitudinal Study of Parents and Children. Curvilinear growth mixture modelling evaluated BMI-adjusted trajectories of both measures. Outcomes were assessed at 24years. Psychotic experiences (PEs), At-Risk-Mental-State status, psychotic disorder and number of PEs were assessed using the Psychosis-Like Symptoms interview PLIKSi (n=3635, 2247 [61.8%]female). Negative symptoms score was measured using the Community Assessment of Psychic Experiences (n=3484, 2161 [62.0%]female). Associations were adjusted for sex, ethnicity, parental social class, cumulative smoking and alcohol use. Relative to stable average, the persistently high omega-6:omega-3 ratio trajectory was associated with increased odds of PEs and psychotic disorder, but attenuated on adjustment for covariates (PEs adjusted odds ratio[aOR] 1.63, 95% confidence interval[CI] 0.92-2.89; psychotic disorder aOR 1.69, 95%CI 0.71-4.07). This was also the case for persistently low DHA (PEs aOR 1.42, 95%CI 0.84-2.37; psychotic disorder aOR 1.14, 95%CI 0.49-2.67). Following adjustment, persistently high omega-6:omega-3 ratio was associated with increased number of PEs (β0.41, 95%CI 0.05-0.78) and negative symptoms score (β0.43, 95%CI 0.14-0.72), as was persistently low DHA (number of PEs:β 0.45, 95%CI 0.14-0.76; negative symptoms:β 0.35, 95%CI 0.12-0.58). Optimisation of PUFA status during development warrants further investigation in relation to psychotic symptoms in early adulthood.

Synthesis, Characterization, and Properties of a Novel Hyperbranched Polymers with Polyacrylamide Side Chains.

A novel hyperbranched polymer with polyacrylamide side chains (HAPAM) was synthesized by aqueous solution polymerization using acrylic acid, acrylamide, 2-acrylamido-2-methyl-1-propanesulfonic acid, hydrophobic monomer of dimethyl octadecyl ammonium chloride, and the homemade skeleton monomer of modified-M2.0 as raw materials and (NH4)2S2O8-NaHSO3 as initiator. The molecular structure, functional groups, and surface morphology of HAPAM were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance hydrogen spectroscopy, and scanning electron microscopy. It was found that the performance of HAPAM solution was higher than that of ordinary polyacrylamide solution in terms of thickening ability, shearing resistance, thermal endurance, salt-resistance, resistance-coefficient and residual-resistance-coefficient, ability to reduce interfacial tension between polymer solution and crude oil, and oil-displacement-efficiency. In particular, the enhanced oil recovery of the HAPAM solution was 13.03%, and the improvement of shearing resistance and immunity to chromatographic separation were simultaneously achieved by the HAPAM solution. These results indicate that the successful synthesis of the novel HAPAM opens a promising strategy for developing new high-performance oil-displacing polymers.

Synthesis and emulsion stability of salt resistant viscosity reducer for heavy oil reservoirs with varying salinities

To address the inadequate salt resistance of viscosity reducers and their limited applicability to reservoirs with single salinity, we synthesized salt-resistant viscosity reducers PANxAn in this study. These compounds were derived from fatty alcohol polyoxyethylene ether acrylate, N-alkyl acrylamide, acrylamide, and 2-acrylamido-2-methylpropanesulfonic acid. The structures were identified using nuclear magnetic hydrogen spectroscopy. We investigated the effects of the hydrophilic group ethoxy-chain length (n = 14, 16, 18, 20 and 22) and hydrophobic group alkyl-chain length (x = 12, 14, 16, and 18) on the salt resistance, interfacial activity, wettability, interfacial viscoelasticity and emulsification viscosity reduction performance of the viscosity reducers. Futher, the structures of the viscosity reducers which can adapt to different salinities were determined. Based on the emulsification viscosity reduction effect, PAN14A16, PAN12A16, PAN12A18, PAN12A20/PAN16A16 and PAN12A22/PAN18A16 adapted to salinities range of 2 × 104-6 × 104, 4 × 104-8 × 104, 6 × 104-10 × 104, 8 × 104-12 × 104 and 10 × 104-14 × 104 mg/L, respectively. At the optimal salinity, PANxAn reduced the oil–water interfacial tension from 28.3 to 5.0 mN/m, dynamic contact angle from 130.0° to 61.0°, and heavy oil viscosity from 454.6 to 60.0 mPa·s with a viscosity reduction rate of 86.80 %. The synthesis of salt-resistant PANxAn provides theoretical guidance and application value for enhancing the recovery efficiency of viscosity-reducer flooding in high-salinity heavy oil reservoirs.

Construction of a novel flavonol fluorescent probe for copper (II) ion detection and its application in actual samples

Copper is an essential trace element in the human body, and its level is directly related to many diseases. While the source of copper in human body is mainly intake from food, then the detection of copper ions (Cu2+) in food becomes crucial. Here, we synthesized a novel probe (E)-3-hydroxy-2-styryl-4H-benzo[h]chromen-4-one (NSHF) and explored the binding ability of NSHF for Cu2+ using nuclear magnetic resonance hydrogen spectroscopy (1H NMR), high-resolution mass spectrometry (HRMS), Job's plot method and density functional theory (DFT). NSHF shows the advantages of fast response time, good selectivity and high sensitivity for Cu2+. The fluorescence intensity ratio (F/F0) of NSHF shows a good linear relationship with the concentration of Cu2+ and the detection limit is 0.061 μM. NSHF was successfully applied to the detection of Cu2+ in real samples. In addition, a simple and convenient Cu2+ detection platform was constructed by combining NSHF with a smartphone and a UV lamp, which can realize the rapid detection of Cu2+. This work provides an effective tool for the real-time detection of Cu2+.

Fundamental properties and intermolecular interaction of triethylene glycol + ethylenediamine aqueous solution for CO2 capture

Solvent absorption as a significant method for carbon dioxide capture, exploring the mechanism of CO2 capture and regeneration solvents is essential for industrial applications. In this work, water (H2O) + (ethylenediamine (EDA) + triethylene glycol (TEG)) system with the constant mole ratio (TEG: EDA = 1: 1) was chosen as the liquid absorbent. In order to gain a deeper comprehension of solution properties of H2O + (EDA + TEG) system, the density (ρ) and viscosity (η) of fundamental properties were measured at P = 1005 hPa and T = (298.15 K to 318.15 K) with the temperature step of 5 K. The excess properties, including excess molar volume (VmE), viscosity deviation (Δη), and excess Gibbs energy of activation of viscous flow (ΔG*E) of H2O + (EDA + TEG) system were calculated from the experimental ρ and η values, and fitted well with the Redlich-Kister polynomial equation. The above results combined with the spectra proved the existence of intermolecular interaction in H2O + (EDA + TEG) system, which favorably fixed CO2. Subsequently, the aqueous solution with mass fraction of 15 wt% EDA and molar ratio EDA: TEG = 1: 1 was used for absorbing CO2 (room temperature) and desorbing (378.15 K) for 5-time cycles, and the cycling absorption performance decreased. So as to explore the reason of degradation, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and nuclear magnetic resonance carbon spectroscopy (13C NMR) were used to analyze the circulating absorption mechanism of CO2 in H2O + (EDA + TEG) system, which revealed that alkyl carbonates and partially indecomposable substance 2-imidazolidinones generated in the cyclic process, and provided some implications for the industrial application.

Self‐Healing, Biocompatible Injectable Hydrogel Based on Multialdehyde Moringa oleifera Gum and Carboxymethyl Chitosan: A Suitable Platform for Drug Delivery in Wound Healing Application

AbstractThis study focuses on synthesizing an injectable hydrogel (IH) using Moringa oleifera gum (MOG) with multi‐aldehyde groups (MOG‐CHO) and carboxymethyl chitosan (CMCh) through a Schiff base reaction at 37 °C. The study includes the optimal concentration of the oxidizing agent to achieve the best content of aldehydes in Moringa oleifera gum. Furthermore, the best oxidized Moringa oleifera gum decides the least gelation time. The physical properties of the optimized IH (IH‐3‐7) are assessed, including color, gel content, porosity, load‐bearing capacity, syringeability, and self‐healing capability. Structural characterization is performed using Fourier transform Infrared spectroscopy (FT‐IR) and nuclear magnetic spectroscopy (1H NMR), while scanning electron microscope (SEM) and rheometer are used to analyze surface morphology and rheological properties. IH‐3‐7 exhibits a porous structure with 35 % porosity and interconnected holes of 1.45 to 4 μm diameter. Higher swelling at pH 5.5 is shown by swelling ratio test conducted in phosphate buffer saline (PBS) at pH 7.4 and pH 5.5. Ciprofloxacin HCl (Cipro) is loaded into IH for release assays, revealing pH‐dependent drug release. In vitro, cytotoxicity assessments on L‐929 fibroblast cell lines show IH′s biocompatibility. Hydrolytic degradation of IH in PBS at pH 7.4 is also evaluated.

Redox-responsive Nanomicelles with Intracellular Targeting and Programmable Drug Release for Targeted Tumor Therapy.

Anti-inflammatory medications, in particular aspirin, have chemopreventive and anticancer adjuvant effects on specific types of cancers, according to ongoing anti-tumor research. Additionally, efforts have been made to transform Poly(salicylic acid) (PSA) into delivery-related nanocarriers. to transport anticancer medications into nanocarriers. However, tumor cell targeting and tumor selectivity were lacking in the salicylic acid polymer-based nanocarriers, preventing them from performing to their full potential. The objective of this study is to prepare targeting and reduction-responsive poly pre-drug nanocarriers (HA-ss-PSA NPs) and to investigate the feasibility of delivering adriamycin (DOX) as nanocarriers. The structures of the polymers were confirmed by nuclear magnetic resonance hydrogen spectroscopy (1H-NMR) and infrared spectroscopy (IR); the encapsulation rate and drug loading of DOX-loaded nanoparticles were determined by HPLC; and the anti-tumor effects of the carriers were evaluated by MTT experiments and in vivo</i> experiments. The prepared nanocarriers had uniform particle size distribution. The drug release rate was up to 80% within 48 h in the tumor environment. DOX/HA-ss-PSA NPs showed significant cytostatic effects. In addition, HA-ss-PSA NPs showed significant targeting and inhibition of cell migration in cell uptake and scratch assays. In vivo</i> experiments showed that the prepared carriers had high tumor inhibition rates, good targeting effects on the liver and tumor, and significantly reduced toxicity to other tissues. The prepared HA-ss-PSA NPs could effectively inhibit the growth of HepG2 cells and tumors in vivo</i>, indicating that PSA could be used as a backbone component of a safe and reliable drug delivery system, providing a new strategy for the treatment of liver cancer.

Synthesis and performance evaluation of a novel zwitterionic quaternary copolymer for enhanced oil‐recovery application

AbstractA novel quaternary copolymer of AA/AM/AOS/C16‐DMAAC was synthesized with acrylic acid (AA), acrylamide (AM), sodium α‐alkenyl‐sulfonate (AOS), and dimethyl‐hexadecyl‐allyl‐ammonium chloride (C16‐DMAAC), using ammonium persulfate and sodium bisulfate (NH4)2S2O8‐NaHSO3) as initiators. The structure of AA/AM/AOS/C16‐DMAAC was characterized using Fourier transform infrared spectroscopy and nuclear magnetic resonance hydrogen spectroscopy. It can be found that the thickening capacity, shearing resistance, temperature‐resistance, salt‐resistance, and emulsification properties of AA/AM/AOS/C16‐DMAAC were superior to those of most widely and cost‐effective partially hydrolyzed polyacrylamide (HPAM) solution at the same concentration. Specifically, the viscosity retention rate of AA/AM/AOS/C16‐DMAAC (3000 mg/L) solution was 86%, which was better than that of HPAM solution (52%) after 30 s of mechanical shearing at 28000 r/min. In addition, the enhanced oil recovery of AA/AM/AOS/C16‐DMAAC solution was 16% at 65 °C, which was about 1.5 times higher than that of HPAM solution (11%). Significantly, successful synthesis of zwitterionic quaternary copolymer emphasizes the importance of a systematic approach to designing appropriate copolymers for enhanced oil recovery.Highlights A novel zwitterionic quaternary copolymer of AA/AM/AOS/C16‐DMAAC was successfully synthesized. The performance on thickening capacity, shearing resistance, temperature‐resistance, salt‐resistance, and emulsification properties of AA/AM/AOS/C16‐DMAAC was superior to that of the most widely used partially hydrolyzed polyacrylamide (HPAM). The enhanced oil recovery of AA/AM/AOS/C16‐DMAAC (16%) was about 1.5 times higher than that of HPAM (11%).

Stability indicating eco-friendly quantitation of terbutaline and its pro-drug bambuterol using quantitative proton nuclear magnetic spectroscopy

Quantitative 1H-NMR became an increasingly important issue in pharmaceutical analytical chemistry. This study used NMR spectroscopy to assay the bronchodilator drug terbutaline sulfate and its pro-drug bambuterol hydrochloride in pure form and pharmaceutical preparations. The technique proceeded using deuterium oxide (D2O) as an 1H-NMR solvent and phloroglucinol anhydrous as an internal standard (IS). Comparatively, to the phloroglucinol signal at 5.9 ppm, the resulting quantitative signals of the studied drugs were corrected. The terbutaline singlet signal at 6.3 ppm was chosen for quantification, while the bambuterol quantitative singlet signal was at 2.9 ppm. The two drugs were rectilinear over the concentration range of 1.0–16.0 mg/mL. LOD values were 0.19 and 0.21 mg/mL while LOQ values were 0.58 and 0.64 mg/mL for terbutaline and bambuterol respectively. The developed method has been validated according to the International Conference of Harmonization (ICH) regarding linearity, accuracy, precision, specificity, and robustness. A greenness profile assessment was applied, and the method proved to be green. The method enables the assay of the two drugs in pure drug and pharmaceutical preparations. The method also enables the assay of the two drugs in the presence of each other; thus, it is considered a stability-indicating method where terbutaline is an acid degradation product of bambuterol.

HR-MAS NMR Metabolomics Profile of Vero Cells under the Influence of Virus Infection and nsP2 Inhibitor: A Chikungunya Case Study.

The arbovirus Chikungunya (CHIKV) is transmitted by Aedes mosquitoes in urban environments, and in humans, it triggers debilitating symptoms involving long-term complications, including arthritis and Guillain-Barré syndrome. The development of antiviral therapies is relevant, as no efficacious vaccine or drug has yet been approved for clinical application. As a detailed map of molecules underlying the viral infection can be obtained from the metabolome, we validated the metabolic signatures of Vero E6 cells prior to infection (CC), following CHIKV infection (CV) and also upon the inclusion of the nsP2 protease inhibitor wedelolactone (CWV), a coumestan which inhibits viral replication processes. The metabolome groups evidenced significant changes in the levels of lactate, myo-inositol, phosphocholine, glucose, betaine and a few specific amino acids. This study forms a preliminary basis for identifying metabolites through HR-MAS NMR (High Resolution Magic Angle Spinning Nuclear Magnetic Ressonance Spectroscopy) and proposing the affected metabolic pathways of cells following viral infection and upon incorporation of putative antiviral molecules.

Revolutionizing colon cancer therapy by site-specific 5-fluorouracil delivery with novel stimuli-responsive mucoadhesive hydrogel: Optimization via response surface methodology

5-fluorouracil (FU) is the key option of systemic therapy for advanced metastatic colon cancer but has a cytotoxic impact on normal cells after intravenous administration therefore the primary goal of this research was to fabricate a unique oral site-specific mucoadhesive delivery technique for FU to reach the colon and improving the targeting effectiveness of FU to colon. In the present research, we investigate the novel utilization of developed carboxymethyl cellulose/polyvinylpyrrolidone-grafted-poly(acrylic acid) based hydrogel as a potential carrier for FU administration. The utilization of such novel hydrogels as potential mucoadhesive and swelling behaviour candidates, carriers of FU for colon cancer, as well as the in-vitro evaluations of FU-release, Fourier transform infrared spectroscopy (FTIR), 13C Nuclear magnetic spectroscopy (13C NMR), X-ray diffraction (XRD), thermal analysis, average molecular weight between crosslinks (Mc), cross-link density, in addition to cytotoxicity analysis, hemocompatibility evaluation and acute oral toxicity analysis, were carried out. Notably, over the initial 36 h of dissolution, FU % cumulative release from CMC/PVP-g-poly (AA) hydrogel ranges from 2.62 % to 6.60 % at 1.2 pH, 7.23 %–11.35 % at 6.8 pH, and 85.48 %–99.63 % at 7.4 pH, respectively. Its thermal stability has been demonstrated by TGA and DSC. The FTIR, 13C NMR and XRD have verified the molecular-level entrapment of FU inside the designed hydrogel. Scanning Electron Microscopy (SEM) results showed that the produced hydrogel had an irregular along with porous surface. The degree of a hydrogel's swelling and crosslink density were found to be negatively correlated with each other, whereas Mc was directly linked with the swelling of accomplished hydrogel. The developed hydrogel with the highest carboxymethyl cellulose (CMC) content demonstrated 147 min of mucoadhesion with colonic mucosal lining. Cytotoxicity analysis, hemocompatibility evaluation and acute oral toxicity testing confirmed the biocompatibility of the fabricated hydrogel and indicated their potential for safe as well as site-specific sustained FU transport as well as being used as a valuable asset of therapeutic agents for colon cancer treatment.

High performance epoxy composites modified by a ladder-like polysilsesquioxane

Developing transparent epoxy resins (EPs) with high mechanical properties, thermally stable, and superior dielectric properties is of vital importance for electronics and communication application. Here we synthesized a novel ladder-like polysilsesquioxane containing phenyl and amino groups (N-PPSQ) via a facile co-condensation process for EP modification. The N-PPSQ features a highly regular ladder-like structure with several reactive amino groups anchored, as confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and nuclear magnetic resonance silicon spectroscopy (29Si NMR). Different EP/N-PPSQ composites with optimized additive contents were prepared. Compared to the pure EP, 10 wt% N-PPSQ addition helps to increase the impact strength of EP by a maximal 73 % while simultaneously improving the tensile and flexural properties. With maintained high transparency and enhanced hygrothermal stability, the EP/N-PPSQ composite shows lower dielectric constant and dielectric loss than pure EP. The work demos a fine solution to improving the toughness, dielectric properties and hygrothermal stability without sacrificing the mechanical and optical properties of EP.

Synthesis and theoretical study of a mixed-ligand indium(III) complex for fabrication of β-In2S3 thin films via chemical vapor deposition.

Two new heteroleptic indium aminothiolate compounds [InClSC2H4N(Me)SC2H4]3[1] and [InSC2H4N(Me)SC2H4(C8H5F3NO)] [2] were synthesized by in situ salt metathesis reaction involving indium trichloride, aminothiol, and N,O-β-heteroarylalkenol ligands. The complexes were subsequently purified and thoroughly characterized by nuclear magnetic resonance (NMR) analysis, elemental studies, mass spectroscopy, and X-ray diffraction single crystal analysis that showed a trigonal bipyramidal coordination of In(III) in both complexes. Thermogravimetric analysis of [1] revealed a multistep decomposition pathway and the formation of In2S3 at 350 °C, which differed from the pattern of [2] due to the lower thermal stability of [1]. Compound [2] exhibited a three-step decomposition process, resulting in the formation of In2S3 at 300 °C. The Chemical Vapor Deposition (CVD) experiment involving compound [2] was conducted on the FTO substrate, resulting in the production of singular-phase In2S3 deposits. A comprehensive characterization of these deposits, including crystal structure analysis via X-ray diffraction (XRD), and surface topography examination through scanning electron microscopy (SEM) has been completed. The presence of In-S units was also supported by the Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and energy dispersive spectroscopy (EDS) of the as-deposited films. Moreover, the electronic structure and thermal properties of compound [2] were investigated through DFT calculations. Electron density localization analysis revealed that the highest occupied molecular orbital (HOMO) exhibited dense concentration at the aminothiolate moiety of the complex, while the lowest unoccupied molecular orbital (LUMO) predominantly resided at the N,O-β-heteroarylalkenolate ligand. Furthermore, our computational investigation has validated the formation of indium sulfide by elucidating an intermediate state, effectively identified through EI-MS analysis, as one of the plausible pathways for obtaining In2S3. This intermediate state comprises the aminothiolate ligand (LNS) coordinated with indium metal.

Preparation and displacement performance of ternary copolymer (HAPEC)/graphene oxide composites

How to deal with high temperature and high salt reservoirs is a great challenge in the field of polymers. In this paper, a functional monomer (APEC) was homemade, copolymerized with acrylic acid and acrylamide to form a terpolymer, and solution blended with graphene oxide (GO) to prepare a terpolymer/graphene oxide composite (HAPEC/GO). The optimal ratio HAPEC/GO = 20:1 (GH20) was screened. The synthesized materials were characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance hydrogen spectroscopy (1H NMR), and electron microscopy (SEM). The temperature sensitivity, salt resistance, rheology, and aging resistance of GH20 were found to be superior to hydrolyzed polyacrylamide (HPAM), as evaluated by the apparent viscosity of the solution. When tested under simulated water conditions of 90 °C and 1.0 × 105 mg/L total mineralization, the GH20 solution demonstrated a further improvement in recovery, reaching 16.99 % compared to water flooding alone. The final recovery was 7.49 % higher than that of HPAM. The results demonstrate that the composite prepared can be effectively utilized in reservoirs with high temperature and high salt conditions, making it a promising method for enhanced oil recovery.