ChemistrySelect最新文献

Silver nanoparticles (AgNPs) were synthesized via a rapid, one-pot green route using Ophiopogon japonicus aqueous extract (OJAE) as both reducing and stabilizing agent, eliminating the need for toxic chemicals. Optimal synthesis conditions (200 µL OJAE, 60°C, 30 min, pH 12, 0.5 mM AgNO₃) were established using a one-factor-at-a-time (OFAT) strategy. UV–vis spectroscopy confirmed AgNPs formation with a distinct surface plasmon resonance peak at 407 nm. The resulting AgNPs were predominantly spherical (15.5 ± 3.0 nm), highly crystalline (d-spacing: 0.238 and 0.256 nm), and stable (zeta potential: −26.7 mV). They exhibited strong antibacterial activity, with inhibition zones against Staphylococcus aureus and Escherichia coli exceeding 98%, comparable to standard antibiotics. Furthermore, the AgNPs achieved > 99% catalytic decolorization of acid blue 29 and acid red 1 within 20 and 6 min, respectively, following pseudo-first-order kinetics (k = 0.2930 ± 0.0189 and 0.9843 ± 0.0873 min⁻¹; r² = 0.9754 and 0.9844). These results establish OJAE as an effective biogenic precursor for producing multifunctional AgNPs with promising applications in antimicrobial therapy and textile wastewater remediation.

Although the brain is protected from systemic chemicals by the blood–brain barrier (BBB), which is composed of specialized vascular endothelium and interacts with astrocytes, neurons, and pericytes, treating problems of the central nervous system (CNS) and neurodegenerative diseases can be difficult. Treatment of diseases of the CNS is hampered by the BBB because of its poor bioavailability and restriction of drug entry, which necessitates chemical modifications to improve drug permeability. Various models for evaluating BBB permeability provide important information for the development and delivery of therapeutic drugs. Drug delivery system research could provide important new information for developing treatments for neurological conditions. Nowadays, research is focused on developing innovative techniques to circumvent the BBB and treat CNS disorders. The conclusion is that improving drug accessibility to the CNS may be best achieved by combining different approaches. This overview describes the most recent developments in the structure and function of the BBB, as well as conventional techniques and factors affecting its permeability, as well as the difficulties and prospects for the future.

In this work, we report the first crosslinking of vanillin with various 1,3-dithiol-2-yl derivatives bearing a wide range of side groups. This original class of vanillinated dithiole molecules was synthesized using a simple one-pot substitution method in a phosphite medium, involving the desulfurization of 1,3-dithiol-2-thione and a hydrogen transfer from the C5-position of 4-hydroxy-3-methoxybenzaldehyde to the C2’-position of the dithiole ring. The new molecules were identified by spectroscopic techniques including FT-IR, UV–vis, ¹H NMR, ¹³C NMR, and 2D NMR (¹H-¹³C HSQC and HMBC), as well as high-resolution mass spectrometry (HMRS). Electrochemical behavior was also studied using cyclic voltammetry. Furthermore, the structures were confirmed by x-ray crystallography. Total electron density, allowing identification of electrophilic and nucleophilic regions. These newly synthesized vanillin derivatives exhibited neuroprotective activity relevant to the management of Alzheimer's disease and demonstrated antidiabetic potential.

Shellfish, being filter feeders, are susceptible to bioaccumulating environmental contaminants. This study examines the occurrence, bioaccumulation, and in vivo transformation of linear alkylbenzene sulfonates (C₁₀–C₁₃ LAS) and their degradation products, sulfophenyl carboxylic acids (C₁₀–C₁₁ SPCs), in the edible clam Meretrix casta from the estuary of Goa, India. Using electrospray ionization-quadrupole time-of-flight tandem mass spectrometry (ESI-QTOF MS/MS), diagnostic fragment ions formed enabled detection and structural characterization of LAS and their biodegradation intermediates in clams under natural conditions. Acute toxicity assays revealed 100% lethality of commercial LAS at 3.5 mg/L, with an LC₅₀ of 2.67 mg/L. Laboratory exposure experiments demonstrated in vivo biotransformation of LAS into oxidized saturated and unsaturated biodegraded products, SPCs, and dicarboxylates (SPdCs) with carbon chains of C₄, C₆, C₈, C₁₀, and C12 for C₁₂LAS and methylated C₁₃SPdCs for C₁₃LAS. This was confirmed by fragment ions analysis using ESI-triple quadrupole (TQ) MS/MS. The study provides the first direct evidence of detailed tandem mass spectrometric data used for characterizing the structure of LAS biodegraded products. These compounds hold potential as biomarkers for pollutant exposure. Their MS-based metabolite detection with the proposed biodegradation pathway can be applied for environmental monitoring and ecological risk assessment. The investigation reveals its metabolic capacity to transform and detoxify, contributing to our understanding of bivalve biotransformation mechanisms and their role in pollutant cycling in coastal ecosystems.

The surface functionalization of magnetic nanoparticles with biocompatible polymers like pectin enhances their biocompatibility and provides a strategy for targeting cancer cells. This paper describes the synthesis of iron oxide (Fe₂O₃) and pectin-coated Fe₂O₃ nanoparticles (Fe₂O₃@Pectin) through a simple ultrasonic-assisted co-precipitation process. The synthesized nanocomposites were characterized by FTIR, XRD, UV-Vis spectroscopy, EDAX, FE-SEM, and VSM, which validated successful pectin functionalization with minimized aggregation (particle size ∼170 nm) and altered magnetic properties (magnetization decreased to 5.20 emu/g after coating). Cytotoxicity tests on HCT-116 human colon carcinoma cells showed dose-dependent cell death, with IC₅₀ of 184.4 ± 0.125 µg/mL for Fe₂O₃@Pectin. DNA fragmentation tests confirmed 96.99% apoptotic DNA damage, suggesting ROS production and mitochondrial disruption as potential mechanisms. The pectin coating improved cellular uptake as evidenced by enhanced cytotoxicity compared to uncoated nanoparticles. This preliminary study provides initial evidence for the potential anticancer activity of Fe₂O₃@Pectin nanoparticles. However, further validation with normal cell line controls is required to establish selectivity and safety. This nano-platform combines the magnetic properties of Fe₂O₃ with the biodegradability of pectin, warranting further investigation as a candidate for targeted cancer therapy.

The emergence of multidrug-resistant (MDR) bacteria and the persistent formation of biofilms on various medical device surfaces present a serious global health challenge, largely driven by overuse of antibiotics. This challenge necessitates the development of multifunctional antimicrobial materials that can effectively prevent bacterial colonization and biofilm formation. Fluorescent carbon dots have recently gained attention as next-generation antimicrobial agents due to their excellent biocompatibility, excellent optical properties, and high chemical stability. Despite extensive studies on Cdots, the self-assembly behavior of these nanoparticles remains largely underexplored, especially in the context of small molecules like amino acids, which are generally used as precursors in the synthesis of Cdots are known to self-assemble independently. In this study, microwave-assisted synthesis of nitrogen-doped Cdots using glucose and L-arginine has been reported. The synthesized self-assembled Cdots exhibited strong blue fluorescence and potent antibacterial activity with a minimum inhibitory concentration (MIC) of 10 µg/mL against MDR bacterial strains. Further, the self-assembled behavior of these Cdots was explored for the formation of uniform antibacterial coatings to inhibit bacterial growth over the applied surfaces. Furthermore, the self-assembled Cdots demonstrated significant antioxidant activity in L929 cell lines and exhibited excellent performance as fluorescent probes for bioimaging applications.

This study investigated the influence of light-curing unit (LCU) choice on the polymerization of commercial composite resins with varying photoinitiator ratios and types, as reflected by their mechanical and physical properties, with a focus on surface hardness and degree of conversion. Four commercially available composite resins (Solitare 2, Filtek Z250, Tetric EvoCeram Bleach, and Tetric EvoCeram Bulk Fill) with distinct photoinitiators were polymerized using four LCUs: one second-generation LED (Elipar S10), two third-generation LED (Bluephase 20i and Valo), and one halogen lamp (Hilux). The data were analyzed using SPSS. The upper surfaces exhibited higher hardness values than the lower surfaces across all composite resins, with Tetric EvoCeram Bleach exhibiting the highest degree of conversion. Thus, the choice of photoinitiator and LCU significantly impacts polymerization and clinical restorative outcomes. This study highlights the limitations of third-generation LED LCUs and other photoinitiators, offering insights for selecting materials and methods to enhance restoration durability. Further research should explore in vivo conditions and additional clinical scenarios to validate these findings.

Two novel compounds, furo[3,2-b]pyrrole carbohydrazone (F₁) and thiocarbohydrazone (F₂), were designed, synthesized, and evaluated as colorimetric sensors for ion detection. Their structures were thoroughly characterized using ¹H-NMR, ¹³C-NMR, and ESI-mass spectroscopy (MS). Although F₁ showed no significant response, F₂ exhibited multi-ion responsiveness for Cu²⁺, Hg²⁺, Ni²⁺, and PO₄³⁻ in a dimethyl sulfoxide (DMSO):phosphate-buffered saline (PBS) medium. The recognition mechanism, binding stoichiometry, and detection limits were examined through ultraviolet (UV)–Vis spectroscopic titrations and theoretical DFT studies. The binding mode was 1:2 (F₂:ion), with detection limits of 3.5, 4.2, 3.2, and 6.9 µM for Hg²⁺, Ni²⁺, Cu²⁺, and PO₄³⁻, respectively. These experimental results were consistent with our theoretical DFT calculations. This work could be considered the first report of a simple, organic colorimetric sensor for the naked-eye detection of PO₄³⁻. This probe's excellent multi-ion responsiveness and practical applicability, demonstrated through paper strip tests and water sample analysis, position it as a promising tool for real-world applications.

The current research work aims to synthesize pH-responsive hydrogel networks of moringa gum (MG)-pectin via in air (IA) method. Different analytical methods like Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), SEM, and x-ray diffraction (XRD) are accustomed to confirming the formation of hydrogel. The natural polysaccharides MG and pectin (PEC) were chosen as backbones for synthesis. The free radical polymerization method was employed using monomer acrylamide (Aam) and MBA (N,N′-methylenebisacrylamide) as a cross-linker. The hydrogel is optimized using various parameters such as backbone ratio, volume of solvent, temperature, time, pH of reaction mixture, concentration of monomer, concentration of cross-linker, and initiator. The optimized hydrogel network exhibits a swelling percentage of 400.8% at pH 7 and temperature 60°C at solvent 24 mL, backbone ratio (1:1), concentration of cross-linker (0.003243 mol L⁻¹), initiator (0.00555 mol L⁻¹), and monomer (0.07034 mol L⁻¹). Additionally, adsorption studies were conducted for crystal violet (CV) dye. The optimum adsorption was achieved at an adsorbent amount 0.5 g at 2 mg L⁻¹ dye concentration and pH of 12 at 20°C. The kinetics of adsorption showed that adsorption follows pseudo-first-order kinetics and best fitted data with Langmuir isotherm, indicating monolayer adsorption process. Endothermic and spontaneous processes are suggested by thermodynamics findings. Thus, the synthesized hydrogel is a potential candidate for dye removal from wastewater solutions and an excellent environment-friendly adsorbent.