Ionic Liquid-Assisted Fabrication of Bioactive Heterogeneous Magnetic Nanocatalyst with Antioxidant and Antibacterial Activities for the Synthesis of Polyhydroquinoline Derivatives

Antibacterial materials have obtained much attention in recent years due to the presence of hazardous agents causing oxidative stress and observation of pathogens. However, materials with antioxidant and antibacterial activities can cause toxicity due to their low biocompatibility and safety profile, urging scientists to follow new ways in the synthesis of such materials. Ionic liquids have been employed as a green and environmentally solvent for the fabrication of electrically conductive polymers. In the present study, an antibacterial poly(p-phenylenediamine)@Fe₃O₄ (PpPDA@Fe₃O₄) nanocomposite was fabricated using [HPy][HSO₄] ionic liquid. The chemical preparation of PpPDA@Fe₃O₄ nanocomposite was initiated through the oxidative polymerization of p-phenylenediamine by ammonium persulfate in the presence of [HPy][HSO₄]. The PpPDA@Fe₃O₄ nanocomposite exhibited antibacterial properties against Gram-negative (Escherichia coli) and Gram-positive (Bacillus subtilis) bacteria. The PpPDA@Fe₃O₄ nanocomposite was employed as a heterogeneous nanocatalysis for one-pot synthesis of polyhydroquinoline derivatives using aromatic aldehyde, dimedone, benzyl acetoacetate, and ammonium acetate. Polyhydroquinoline derivatives were synthesized in significant yields (90–97%) without a difficult work-up procedure in short reaction times. Additionally, PpPDA@Fe₃O₄ nanocatalyst was recycled for at least five consecutive catalytic runs with a minor decrease in the catalytic activity. In this case, 11 derivatives of polyhydroquinoline showed in vitro antioxidant activity between 70–98%.     

A Lignoid Glycoside and Dimeric Phenylpropanoids from Daphne oleoides

Three new natural products, a lignoid glycoside 1 and two dimeric phenylpropanoids 2 and 3 , along with two known lignans 4 and 5 , were isolated from the BuOH‐ and CHCl₃‐soluble fractions of the whole plant of Daphne oleoides (Thymelaeaceae). The structures of the new compounds were established by spectroscopic techniques, including 2D NMR, as 4‐(β‐D ‐glucopyranosyloxy)‐9′‐hydroxy‐3,3′,4′‐trimethoxy‐7′,9‐epoxylignan ( 1 ), (1R,2S,5R,6R)‐6‐(3‐ethyl‐4‐hydroxy‐5‐methoxyphenyl)‐2‐(4‐hydroxy‐3,5‐dimethoxyphenyl)‐3,7‐dioxabicyclo[3.3.0]octane ( 2 ) and (1R,2S,5R,6S)‐2,6‐bis(3‐ethyl‐4‐hydroxy‐5‐methoxyphenyl)‐3,7‐dioxabicyclo[3.3.0]octane ( 3 ). The other lignans were identified as (+)‐pinoresinol O‐(β‐D ‐glucopyranoside) ( 4 ) and (+)‐medioresinol ( 5 ).     

CoCo-PBA/tetrabutylammonium bromide as highly efficient catalyst for CO2 and epoxides coupling reaction under mild conditions

The development of effective and low-energy-consumption catalysts for CO₂conversion into high-valueadded products by constructing versatile active sites on the surface of heterogeneous compounds is an urgent and challenging task.In this study,a stable and well-defined heterogeneous cobalt hexacyanocobaltate (Co₃[Co（CN）₆]₂),typical cobalt Prussian blue analogue （Co Co-PBA） modified with tetrabutylammonium bromide （TBAB）,is proven to be the superior cata...     

Recent Progress in Polyaniline and its Composites for Supercapacitors

Polyaniline (PANI) has piqued the interest of nanotechnology researchers due to its potential as an electrode material for supercapacitors. Despite its ease of synthesis and ability to be doped with a wide range of materials, PANI′s poor mechanical properties have limited its use in practical applications. To address this issue, researchers investigated using PANI composites with materials with highly specific surface areas, active sites, porous architectures, and high conductivity. The resulting composite materials have improved energy storage performance, making them promising electrode materials for supercapacitors. Here, we provide an overview of recent developments in PANI-based supercapacitors, focusing on using electrochemically active carbon and redox-active materials as composites. We discuss challenges and opportunities of synthesizing PANI-based composites for supercapacitor applications. Furthermore, we provide theoretical insights into the electrical properties of PANI composites and their potential as active electrode materials. The need for this review stems from the growing interest in PANI-based composites to improve supercapacitor performance. By examining recent progress in this field, we provide a comprehensive overview of the current state-of-the-art and potential of PANI-based composites for supercapacitor applications. This review adds value by highlighting challenges and opportunities associated with synthesizing and utilizing PANI-based composites, thereby guiding future research directions.     

Advancements in Perovskite-Based Cathode Materials for Solid Oxide Fuel Cells: A Comprehensive Review

The high-temperature solid oxide fuel cells (SOFCs) are the most efficient and green conversion technology for electricity generation from hydrogen-based fuel as compared to conventional thermal power plants. Many efforts have been made to reduce the high operating temperature (>800 °C) to intermediate/low operating temperature (400 °C<T<800 °C) in SOFCs in order to extend their life span, thermal compatibility, cost-effectiveness, and ease of fabrication. However, the major challenges in developing cathode materials for low/intermediate temperature SOFCs include structural stability, catalytic activity for oxygen adsorption and reduction, and tolerance against contaminants such as chromium, boron, and sulfur. This research aims to provide an updated review of the perovskite-based state-of-the-art cathode materials LaSrMnO₃ (LSM) and LaSrCOFeO₃ (LSCF), as well as the recent trending Ruddlesden-Popper phase (RP) and double perovskite-structured materials SOFCs technology. Our review highlights various strategies such as surface modification, codoping, infiltration/impregnation, and composites with fluorite phases to address the challenges related to LSM/LSCF-based electrode materials and improve their electrocatalytic activity. Moreover, this study also offers insight into the electrochemical performance of the double perovskite oxides and Ruddlesden-Popper phase materials as cathodes for SOFCs.     

Shock waves in a rotating non-Maxwellian viscous dusty plasma

A theoretical model is presented to study the characteristics of dust acoustic shock in a viscous, magnetized, rotating dusty plasma at both fast and slow time scales. By employing the reductive perturbation technique, the non-linear Zakharov–Kuznetsov–Burger (ZKB) equation is derived for both cases when the dust is inactive and dynamic (fast and slow time scales). Both electrons and ions are considered to follow the kappa/Cairns distribution. It is observed that in both cases, i.e. when dust is in the background and active, viscosity plays a key role in dissipation for the propagation of acoustic shock. Magnetic field and rotation are responsible for the dispersive term. Superthermality is found to affect significantly the formation of the shock wave along with viscous nature of plasma, whereas the dust charge affects the non-linear coefficient of the ZKB equation. The present investigation may be beneficial to the understanding of the rotating plasma, in particular the experiments being carried out.     

Ion acoustic solitary waves in magnetized electron–positron–ion plasmas with Tsallis distributed electrons

The propagation of ion acoustic (IA) solitary waves is investigated in a magnetized electron-positron-ion (EPI) plasma with Tsalli distributed electrons and Maxwellian positrons. A non-linear Korteweg–de Vries (KdV)-type equation is derived for the potential by using the reductive perturbation method (RPM), and its solitary wave solution is analysed. For a given set of plasma parameters, the present model supports only compressive IA solitary structures. It is found that the variation of various relevant plasma parameters, like the nonextensive parameter q, temperature ratio σ , direction cosine l_z , the positron concentration γ and the magnetic field strength Ω significantly alter the characteristic properties of IA solitary waves.     

Potential Antiviral Action of Alkaloids

Viral infections and outbreaks have become a major concern and are one of the main causes of morbidity and mortality worldwide. The development of successful antiviral therapeutics and vaccines remains a daunting challenge. The discovery of novel antiviral agents is a public health emergency, and extraordinary efforts are underway globally to identify safe and effective treatments for different viral diseases. Alkaloids are natural phytochemicals known for their biological activities, many of which have been intensively studied for their broad-spectrum of antiviral activities against different DNA and RNA viruses. The purpose of this review was to summarize the evidence supporting the efficacy of the antiviral activity of plant alkaloids at half-maximum effective concentration (EC₅₀) or half-maximum inhibitory concentration (IC₅₀) below 10 μM and describe the molecular sites most often targeted by natural alkaloids acting against different virus families. This review highlights that considering the devastating effects of virus pandemics on humans, plants, and animals, the development of high efficiency and low-toxicity antiviral drugs targeting these viruses need to be developed. Furthermore, it summarizes the current research status of alkaloids as the source of antiviral drug development, their structural characteristics, and antiviral targets. Overall, the influence of alkaloids at the molecular level suggests a high degree of specificity which means they could serve as potent and safe antiviral agents waiting for evaluation and exploitation.     

Preparation of Losartan Potassium Controlled Release Matrices and In-Vitro Investigation Using Rate Controlling Agents

Controlled release matrices have predictable drug release kinetics, provide drugs for an extended period of time, and reduce dosing frequency with improved patient compliance as compared with conventional tablet dosage forms. In the current research work, losartan potassium controlled release matrix tablets were fabricated and prepared with rate altering agents; that is, Ethocel grade 100 combined with Carbopol 934PNF. Various drug to polymer ratios were used. HPMC, CMC, and starch were incorporated in some of the matrices by replacing some amount of filler (5%). The direct compression method was adopted for the preparation of matrices. In phosphate buffer (pH 6.8), the dissolution study was conducted by adopting the USP method-I as the specified method. Drug release kinetics was determined and dissolution profiles were also compared with the reference standard. Prolonged release was observed for all matrices, but those with Ethocel 100FP Premium showed more extended release. The co-excipient (HPMC, CMC, and starch) exhibited enhancement in the drug release rates, while all controlled release matrices released the drug by anamolous non-Fickian diffusion mechanism. This combination of polymers (Ethocel grade 100 with Carbopol 934PNF) efficiently extended the drug release rates up to 24 h. It is suggested that these matrix tablets can be given in once a day dosage, which might improve patient compliance, and the polymeric blend of Ethocel grade 100 with Carbopol 934PNF might be used in the development of prolonged release matrices of other water-soluble drugs.