RSC Advances最新文献

In order to lessen the severity of infectious diseases, anti-infective agents-drugs that prevent, combat, or control infections brought on by microorganisms-are essential in contemporary medicine. To tackle antimicrobial resistance, this project intends to design and synthesize hybrid compounds that contain pyrrolidine, quinoxaline and a hydrazinyl bridge, and assess the antimicrobial and antifungal properties of these compounds against a variety of pathogenic strains. The bactericidal properties of hybrids 24, 27, and 29 against E. coli were verified. The MIC of 12.5 µM was shown by hybrids 24, 25, and 31, which suggests bactericidal hybrids are effective against P. aeruginosa at greater concentrations. In comparison to Levofloxacin, treatment with all hybrids produced an 89-92% reduction in biofilm formation at 90% MIC. Eight hybrids' killing kinetics against P. aeruginosa were time-dependent, with an abrupt decrease in CFU number observed at higher concentrations. While 4-fold and 8-fold MICs resulted in nearly total bacterial eradication, primary bacterial elimination happened after three hours. The most effective DNA gyrase inhibitors were hybrids 25, 28, and 31; their IC₅₀ values were significantly less than that of ciprofloxacin (77.3, 87.6, and 65.5 µM, respectively). To determine the best drug-like qualities, the study examined the physicochemical and pharmacokinetic features of active compounds. Molecular docking simulation experiments were also conducted to comprehend the binding interactions and mechanisms of action of these hits.

Food waste is a sustainable and attractive waste biomass which can be utilized as a substrate for the production of value-added bioproducts. In this study, Y. lipolytica engineered for d-lactic acid (DLA) production was optimised for food waste hydrolysate (FWH) and fish protein hydrolysate (FPH). The substrate inhibition studies using FWH showed that after a 50 (g L^-1) concentration of glucose, there was a decline in both specific growth rate and DLA yield, and the Luong model with an R ² of 0.933 gave a better model fit. Nitrogen screening studies revealed that fish protein hydrolysate (FPH) could be an economical replacement for yeast extract. The Placket-Burman (PB) screening evaluation revealed that FWH, pH, and KH₂PO₄ were the key factors affecting DLA production. Furthermore, in central composite design (CCD) studies with optimal parameter levels, an 8.7% increase in DLA production was observed. Additionally, using an Artificial Neural Network (ANN)-linked Genetic Algorithm (GA), optimised parameter levels of FWH 49.98 (g L^-1), pH 8.52, and KH₂PO₄ 3.93 (g L^-1) were obtained, enhancing DLA production by 12.6% compared with the Plackett-Burman studies. Bioreactor studies with FPH as the only nitrogen source and FWH as the carbon source exhibited 0.94 (g g^-1) DLA yields, which were similar to the GA prediction. Kinetic modelling studies using MATLAB/Simulink showed that DLA production followed a mixed growth-dependent product-formation pattern. DLA purification using a butanol and ammonium sulfate solvent system yielded 92.7% recovery efficiency with glucose as the carbon source, and 83.51% recovery efficiency with FWH as the carbon source. Furthermore, characterization with HPLC, FTIR, and NMR reiterated the presence of DLA.

Industrial production of amoxicillin trihydrate (AMCT) often suffers from low yield, impurity inclusion, and inconsistent crystal morphology. This study introduces a scalable green crystallization strategy using malic acid as a biodegradable habit modifier, developed as part of an improved eco-friendly AMCT manufacturing framework. A hybrid optimization approach integrating Taguchi design with Artificial Neural Network (ANN) modeling was employed to capture both linear and nonlinear interactions among critical process variables. Multi-technique characterization (XRD, FTIR, DSC, BET, LC-MS) confirmed that malic acid preserves lattice integrity while substantially refining particle attributes, reducing crystallite size from 85.9 to 66.4 nm and increasing specific surface area from 5.27 to 11.07 m² g^-1. This significant increase in surface area is a key physical factor theoretically favoring improved dissolution kinetics. The ANN model exhibited excellent predictive performance (R ² > 0.99) for both purity and yield. Under optimized conditions (2.5 M malic acid, pH 5.5, 60 min, 1500 rpm), AMCT crystals were obtained with 99.21% purity and 61.82% yield. These results demonstrate a robust, data-driven framework for sustainable AMCT production, providing a high-performance alternative to conventional mineral-acid-based crystallization methods.

The development of efficient, cost-effective, and noble-metal-free electrocatalysts is critical for sustainable hydrogen production via water splitting. Herein, hierarchical MoS₂ nanosheets were synthesized through a facile hydrothermal method, producing a marigold flower-like morphology with abundant exposed edge sites. Structural and compositional analyses using XRD, Raman, XPS, SEM, and BET confirmed the formation of crystalline, layered, and mesoporous MoS₂. Electrochemical evaluation in 1.0 M KOH revealed excellent hydrogen evolution reaction (HER) activity, with a low overpotential of 180 mV at 10 mA cm^-2, a Tafel slope of 122.3 mV dec^-1, and reduced charge-transfer resistance, highlighting efficient electron transport. Chronoamperometric measurements demonstrated outstanding long-term stability over 10 h. The combination of tailored morphology, high surface area, and favorable electronic structure establishes hydrothermally synthesized MoS₂ as a promising and practical electrocatalyst for sustainable hydrogen generation.

Formic acid (HCOOH) is one of the simplest carboxylic acids detected in interstellar and circumstellar environments, often associated with prebiotic organic chemistry. In this work, we combine laboratory data from the radiolysis of pure HCOOH ice at 15 K by 267 MeV ⁵⁶Fe²²⁺ ions with kinetic simulations performed using the PROCODA code. This numerical model solves a system of coupled differential equations describing 1631 reactions among 73 molecular and radical species, allowing the determination of effective reaction rate coefficients (ERCs), equilibrium abundances, and desorption yields. The best-fit model successfully reproduces experimental infrared data and predicts the formation of non-observed intermediates such as HOCO, CH₂OO, and H₂CO. The results indicate that CO, CO₂, and H₂O are the dominant radiolysis products, while HCOOH acts primarily as a transient radical source rather than a net precursor of complex organics. Hydrogen abstraction and radical recombination were identified as the main mechanisms governing molecular evolution, with HOCO and OH radicals playing key intermediate roles. The calculated desorption yield (1.5 × 10⁵ molecules per ion) and effective rate constants confirm the efficiency of heavy ion sputtering in cold ices. These findings provide quantitative insight into the radiation-driven chemistry of formic acid and offer constraints for astrochemical models of dense clouds, protostellar disks, and icy moons.

Developing efficient catalysts for p-nitroaniline hydrogenation under green conditions is pivotal for sustainable chemical synthesis. Herein, we report a Pt catalyst supported on a self-made _prCeO₂ support that achieves >99% yield in the hydrogenation of p-nitroaniline to p-phenylenediamine under exceptionally green conditions (35 °C, 5 mg catalysts, 69 mg substrate, H₂ balloon, 10 h, 2 mL methanol solvent). The superior performance is linked to paramagnetic active sites at the Pt-_prCeO₂ interface, generated at an optimal reduction temperature of 400 °C, and enhanced hydrogen spillover via their unpaired electrons. After reusing it 20 times, it still retains 50% of its original performance. This work introduces paramagnetic active sites as a novel strategy for catalysis chemistry and synthesis.

The rising demand for sustainable energy has intensified research on supercapacitors that can achieve high energy density, rapid power delivery, and excellent cycling durability. To achieve these attributes, considerable research has been directed to engineering diverse electrode materials, including carbon-based structures, transition metal oxides, together with their sulfide and phosphide counterparts, and conducting polymers. Metal Organic Frameworks (MOFs) have emerged as potential electrode materials driven by their tunable porosity and high surface area, yet their low intrinsic conductivity and structural instability limit direct application in supercapacitors. We have reported a hydrothermally synthesized trimetallic NiCoZn-MOF and calcined this to produce a metal-oxide/carbon framework. This framework was utilized for the in situ growth of NiCo₂S₄ nanoparticles. The resulting metal-oxide/carbon framework@NiCo₂S₄ nanocomposite combines the electrical conductivity and redox activity of sulfides along with the stability and high surface area of the MOF-derived matrix. The optimized electrode (1 wt% calcined-MOFs/1.5 wt% NiCo₂S₄) exhibited a specific capacity (Q _s) of 458.5 C g^-1 at 0.5 A g^-1. The assembled asymmetric supercapacitor achieved an energy density (E _d) of 76 W h kg^-1 at a power density (P _d) of 700 W kg^-1 and a coulombic efficiency of 98%. It retained 80.01% capacitance after 5000 cycles. Dunn's analysis indicated that charge storage was primarily diffusion controlled. These findings demonstrate the superior performance of MOF-derived sulfide nanocomposites as effective electrode materials for application of high-performance supercapacitors.

Iron (Fe) is essential for biological systems, with ferric (Fe³⁺) and ferrous (Fe²⁺) states possessing biological significance. Imbalances in Fe³⁺ levels can lead to major health concerns. It necessitates accurate and specific detection of Fe³⁺ in drinking water sources. This study offers an eco-friendly, cost-effective colorimetric nanosensor for Fe³⁺ detection using silver nanoparticles (AgNPs) synthesized from garlic-derived alliin and bovine serum albumin (BSA). The nanoparticles were studied using UV-visible spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). The AgNPs exhibited a plasmonic peak at 420 nm and TEM revealed spherical particles with an average diameter of 12.17 ± 0.60 nm. XPS analysis validated the binding energies of S 2p, C 1s, Ag 3d, N 1s, and O 1s. XRD showed that the AgNPs have a face-centered cubic (FCC) structure. The sensor has a detection limit of 5.54 fM for Fe³⁺, with the highest sensitivity at pH 4 (68.80 ± 1.05% relative activity). Kinetic analysis indicated that zero-order kinetics provided the best fit under the given conditions. Computational modelling indicates a stable Fe³⁺ interaction with the NH group of BSA's histidine and the CHO group of alliin, with a binding energy of 16.1 kcal mol^-1. This supports the formation of a stable Ag-alliin-Fe complex. The sensor effectively detects Fe³⁺ in real water samples, underscoring its practical potential for environmental monitoring.

Cutaneous melanoma, a malignant neoplasm originating from melanocytes, has exhibited a steadily rising incidence worldwide. Conventional therapeutic strategies often suffer from limited precision, resulting in significant off-target toxicity or failure to prevent disease recurrence. Hydrogels have emerged as a promising platform for localized drug delivery in cutaneous melanoma treatment, owing to their chemically designable three-dimensional networks, tunable crosslinking strategies, and excellent biocompatibility. These structural features enable controlled, on-demand release kinetics and responsiveness to the tumour microenvironment, thereby facilitating multimodal therapy such as chemotherapy, radiotherapy, phototherapy, immunotherapy, and chemodynamic therapy, with enhanced therapeutic efficacy and reduced systemic toxicity. This review systematically examines the chemical composition and crosslinking strategies underpinning hydrogel design, with an emphasis on how these structural parameters influence therapeutic outcomes. Recent advances in tumour microenvironment-responsive hydrogels are further highlighted to elucidate the structure-activity relationships that inform the rational design of next-generation drug delivery systems.

This study explores a sustainable "waste-treating-waste" strategy by synthesizing two distinct adsorbents, tank-bottom oily sludge adsorption material (TSAM) and refinery oily sludge adsorption material (RSAM). These materials are produced by pyrolysis at 800 °C and applied to the removal of complex sulfide ore flotation wastewater. Characterization results revealed that RSAM possesses a superior surface area (204 m² g^-1) and a well-developed mesoporous structure, providing abundant active sites for organic molecules. In contrast, TSAM is characterized by a higher ash content and the presence of active mineral phases, such as CaS and FeS, which play a crucial role in heavy metal pollutant immobilization. Adsorption experiments demonstrated distinct but complementary performance: RSAM exhibited exceptional removal efficiency for butyl xanthate (BX), achieving 99.60% removal within 45 minutes, a process primarily driven by physical mechanisms, including pore filling within the carbon matrix and strong hydrophobic interactions between the adsorbent surface and xanthate. Conversely, TSAM showed superior efficacy in removing heavy metal ions (Cd²⁺, Cu²⁺, Zn²⁺) with removal efficiencies exceeding 97%. The removal of heavy metals by TSAM was governed by combined chemical mechanisms, involving chemical precipitation (forming stable metal sulfides and carbonates), surface complexation with oxygen-containing functional groups, and ion exchange, further facilitated by the material's strong alkaline-buffering capacity. The treatment of actual flotation wastewater demonstrated that pollutant levels were significantly below discharge limits. This research provides a cost-effective solution for the simultaneous removal of organic and heavy metal pollutants, demonstrating the high-value valorization of petroleum hazardous waste within a circular economy framework.