Ammonium Research Articles

<i>In vitro</i> study of the bactericidal activity for new derivatives of quaternary ammonium salts based on pyridoxine against gram-positive / gram-negative bacteria

BACKGROUND: Preventive care and successful treatment of infectious diseases (including hospital-acquired infections) are among the most important tasks of modern healthcare. Not many effective antiseptics and disinfectants available can solve this problem. Quaternary ammonium salts are currently one of the promising classes of disinfectants; however, their use is limited by the ability of microorganisms to develop resistance to the compounds. Modification of quaternary ammonium salts with substituents of various profiles is a possible way to solve this problem. AIM: To conduct a comparative analysis of the bactericidal activity of two original quaternary ammonium compounds based on pyridoxine in comparison with benzalkonium chloride. MATERIALS AND METHODS: The bactericidal profiles of 0.1 and 0.2% aqueous solutions of original quaternary ammonium salts based on pyridoxine were studied against two widespread pathogens: Staphylococcus aureus and Escherichia coli. Antibacterial activity data were obtained using a standard in vitro test (bactericidal activity test on a metal surface; exposure time of 1, 5, and 15 min). In addition to standard conditions, antibacterial efficacy was studied under protein loading conditions, in which BSA solution was added to the surface. RESULTS: For the studied compounds, the reduction factor (RF, reduction lgCFU of microorganisms) was on average ≥3. Protein loading led to a decrease in efficiency by 1–3 times. An interesting effect of exposure time-dependent specificity reversal to the S. aureus and E. coli was observed. CONCLUSIONS: The results showed the high activity of the studied compounds, which corresponds to the effectiveness criterion of RF ≥3 for commercial compounds used in this field.

How sensor Amt-like proteins integrate ammonium signals.

Unlike aquaporins or potassium channels, ammonium transporters (Amts) uniquely discriminate ammonium from potassium and water. This feature has certainly contributed to their repurposing as ammonium receptors during evolution. Here, we describe the ammonium receptor Sd-Amt1, where an Amt module connects to a cytoplasmic diguanylate cyclase transducer module via an HAMP domain. Structures of the protein with and without bound ammonium were determined to 1.7- and 1.9-Ångstrom resolution, depicting the ON and OFF states of the receptor and confirming the presence of a binding site for two ammonium cations that is pivotal for signal perception and receptor activation. The transducer domain was disordered in the crystals, and an AlphaFold2 prediction suggests that the helices linking both domains are flexible. While the sensor domain retains the trimeric fold formed by all Amt family members, the HAMP domains interact as pairs and serve to dimerize the transducer domain upon activation.

Biodegradable quaternized silk fibroin sponge with highly uniform pore structure for traumatic hemostasis and anti-infection

Developing a biodegradable sponge with rapid shape recovery and potent antibacterial and coagulation properties for traumatic hemostasis and anti-infection remains challenging. Herein, we fabricated quaternized silk fibroin (SF) sponges by freeze-drying under a constant cooling rate and modification with quaternary ammonium groups. We found the constant cooling rate enabled the sponges with a highly uniform pore structure, which provided excellent self-elasticity and shape recovery. Decoration with quaternary ammonium groups enhanced blood cells adhesion, aggregation, and activation, as well as resistance to infections from Staphylococcus aureus and Escherichia coli. The SF sponge had superior hemostatic capacity to gauze and commercial gelatin sponge in different hemorrhage models. The SF sponge exhibited favorable biodegradability and biocompatibility. Moreover, The SF sponge also promoted host cell infiltration, capillary formation, and tissue ingrowth, suggesting its potential for guiding tissue regeneration. The developed SF sponge holds great application prospects for traumatic hemostasis, anti-infection, and guiding tissue regeneration.

Antimicrobial, anti‐inflammatory, and antioxidant evaluations of ammonium and phosphonium salts based on poly(vinylbenzyl chloride‐co‐acrylonitrile)

AbstractPolymers with ammonium or phosphonium salts have been known to possess antimicrobial activity. Herein, synthesis of poly(vinylbenzyl chloride‐co‐acrylonitrile) (P(VBC‐co‐AN)) is reported via a free radical polymerization by employing AIBN as initiator. The copolymer was then quaternized using triethylamine, triphenylphosphine, and tributylphosphine. The triphenylphosphonium salt was selected for further modification, on which the polyacrylonitrile chains were reacted with two different amines: tris (2‐aminoethylamine) and diethylenetriamine. The copolymerization, quaternization, and amination reactions were confirmed by spectroscopic and morphologic analysis besides the thermal features. The water uptake of modified polymers was investigated, where tributylphosphonium salt (KH4) showed the highest water uptake capacity (41 g/g). The antimicrobial assay findings demonstrated that all the evaluated copolymers displayed a wide range of antimicrobial activity against different multidrug resistant human pathogens, for example polymer coded KH4 containing tributylphosphonium salt showed the highest growth inhibition rates against Staphylococcus aureus and Staphylococcus epidermidis populations, recorded 87% and 72%; respectively. The anti‐inflammatory activity revealed that all the quaternized copolymers have a protection effect of human erythrocyte membrane against lysis. Antioxidant results revealed that all quaternized copolymers displayed 1,1‐diphenyl‐2‐picryl hydrazyl scavenging activities. Among the studied copolymers, aminated copolymer coded (KH6) exhibited the highest scavenging activity, with IC50 ~ 120 μg/mL.

Complexes of Alkali Metal and the Ammonium Ion with the Cyclodimethylsiloxane Ligands D7 and D8 (D=Me2SiO)

AbstractWe present complexes of alkali metal ions and the ammonium ion with the large cyclodimethylsiloxanes D7 and D8 (D=Me2SiO). The formation of such complexes is accompanied by rearrangements of the ligands to form complexes with a suitable ring size for the metal used. These rearrangements could be suppressed by suitable reaction conditions and rapid work‐up of the reaction mixtures. This enabled the isolation of [Li(D7)][GaI4] (1), [Li(D8)][GaI4] (2), [Na(D8)][GaI4] (3), [K(D8)][GaI4] (4) and [NH4(D8)][GaI4] (5). All of the prepared compounds were analysed using single‐crystal X‐ray diffraction as well as multinuclear NMR spectroscopy. This reveals very different coordination modes in the compounds obtained.

Bipolar Pseudohalide Ammonium Salts Bridged Perovskite Buried Interface toward Efficient Indoor Photovoltaics

AbstractDue to the higher photon energy under indoor photovoltaic conditions, using perovskite materials with wider bandgaps has become a consensus. However, updating perovskite absorbers requires additional adaptations involving at least two layers of transport materials and two interfaces, increasing the development complexity. This study acknowledges that the buried interface is the primary location for the generation of photoinduced carriers, and achieving efficient carrier separation and transport at this interface will solve most of the open circuit voltage (VOC) loss issues encountered in transitioning from solar photovoltaics to indoor photovoltaics. Therefore, a class of bipolar pseudohalide ammonium salts is proposed for use as bridging agents for the buried interface to effectively resolve the issues of lattice misalignment and insufficient carrier driving force at the buried interface when broadening the perovskite bandgap, thereby reducing VOC loss in indoor photovoltaics. The optimized device exhibits an excellent photoelectric conversion efficiency (PCE) of 41.04%, with a record‐high VOC of 1.08 V. It also demonstrates impressive long‐term operational stability with a T80 lifetime of 1000 h. Substituting various non‐buried interface transport materials and different categories of wide‐bandgap perovskite absorbers does not alter the effectiveness, proving its universality.

Magnesium in Soils of Agricultural Landscapes of Western Siberia

Background: Western Siberia has great potential for crop and livestock production; it is limited by degradation of soil fertility due to depletion of biophilic elements, including Mg. Intensification of agricultural production requires monitoring and optimization of magnesium nutrition of field crops. This study aimed at investigating changes in content of magnesium forms Gleyic Chernozems and Luvic Greyzemic Phaeozem in the Western Siberia during their long-term agricultural use. Methods: Soil samples were taken from the fields of long-term experiments in 1978, 1988 and 2019. Three cores were taken from a soil layer 0-20, 20-40 cm thick and combined into composite samples. Composite samples were kept in the archives of the institute. Chemical analysis of composite soil samples was carried out in 2020. Chemical analyzes of soil and plants were carried out by conventional methods. Magnesium forms were extracted: easily exchangeable with 0.0025 M CaCl2 solution, exchangeable with 1 M CH3COONH4, non-exchangeable with 1 M HNO3 and determined on an atomic absorption spectrometer. Result: Systematic use of the ammonia form of nitrogen fertilizers (60-120 kg a.m./ha per year) led to a decrease in mobile forms of magnesium in the most root-inhabited soil layer. The removal of magnesium by potatoes was small (8-10 kg/ha, 80 % falls on the tops). Consequently, a significant decrease in the reserves of magnesium available to plants in soils is associated not so much with the alienation of the element with yield, but with leaching processes due to the displacement of magnesium from the soil-absorbing complex by ammonium ions introduced with fertilizers and also, probably, potassium.

Corrosion Inhibition Properties of Corrosion Inhibitors to under-Deposit Corrosion of X65 Steel in CO2 Corrosion Conditions.

Under-deposit corrosion is widely present in the pipelines of oil and gas production, causing significant corrosion damage. In this paper, a novel electrochemical cathodic-polarization method was carried out to accelerate the formation of CaCO3 scale on a X65 steel surface in a simulated solution containing scaling ions. Subsequently, pre-scaled X65 steel was placed in a high temperature and pressure autoclave to conduct corrosion weight-loss experiments and in situ electrochemical measurements. The study mainly compared the corrosion inhibition behavior of four quaternary ammonium salt corrosion inhibitors, pyridinium quaternary salt (BPC), quinolinium quaternary salt (BQC), 8-hydroxyquinolinium quaternary salt (BHQ) and pyridinium (1-chloromethyl naphthalene) quaternary salt (1-CPN), in a simulated oilfield scale under corrosive conditions. The results of the weight-loss experiments demonstrated that the inhibition efficiencies of the corrosion inhibitors from high to low were as follows: 1-CPN < BHQ < BQC < BPC. The in situ electrochemical measurements showed that the immersion time and type of corrosion inhibitor had a pronounced influence on the corrosion and corrosion inhibition behavior of X65 steel with CaCO3 coating. It was also proved using both EIS and PC that 1-CPN shows the best inhibition performance in all. Lastly, the inhibition mechanism of corrosion inhibitors at under-deposit conditions was analyzed via a surface morphology observation of SEM.

Durable antibacterial cotton fabrics with good performance enabled by quaternary ammonium salts

Durable antibacterial cotton fabrics with good performance enabled by quaternary ammonium salts

Strategic control of combustion-induced ammonia emissions: A key initiative for substantial PM2.5 reduction in Tianjin, North China Plain

Information on the temporal and spatial variations in the sources of ammonium salts (NH4+), a crucial alkaline component in PM2.5, is limited. Here, we simultaneously collected PM2.5 and gaseous ammonia (NH3) samples in both summer and winter from two sites in Tianjin: an urban site (Tianjin University, TJU) and a suburban site (Binhai New-region, BH). NH3 concentrations, the contents of major water-soluble inorganic ions in PM2.5, and the compositions of ammonium‑nitrogen isotopes (δ15N-NH4+) were measured. As a result, (NH4)2SO4 and NH4NO3 were the predominant forms of NH4+ in PM2.5 during summer and winter, respectively. However, the NH4NO3 concentrations were notably greater at TJU (6.2 ± 7.3 μg m−3) than at BH (3.8 ± 4.7 μg m−3) in summer, with no regional differences observed in winter. Both sites displayed almost half the contribution of c-NH3 (combustion-related NH3) to NH4+, differing from the finding of previous isotope-based studies. This discrepancy could be attributed to the combined effects of NHx isotope fractionation and seasonal δ15N value variations in NH3 sources. The contribution fractions of v-NH3 (volatile NH3) and c-NH3 exhibited similar patterns at both sites seasonally, probably caused by coal combustion for heating in winter and temperature fluctuations. However, the contribution fraction of c-NH3 was lower at BH than at TJU in summer but greater in winter than at TJU. In summer, NH4NO3 was unstable and limited its delivery to TJU from BH, and the high contribution of c-NH3 to NH4+ at TJU could be attributed to local vehicle emissions. In winter, the stable particulate NH4NO3 that formed from the c-NH3 in the upwind area could be transported to the downwind area, increasing the NH4+ concentration at BH. Our study provides valuable insights for devising emission mitigation strategies to alleviate the increasing burden of NH3 in the local atmosphere.

Biomaterial-based sponge for efficient and environmentally sound removal of bacteria from water

Designing materials capable of disinfecting water without releasing harmful by-products is an ongoing challenge. Here, we report a novel polycationic sponge material synthesized from chitosan derivatives and cellulose fibers, exhibiting antibacterial properties. The design of such material is based on three key principles. First, the formation of a highly porous structure through cryogelation for an extensive surface area. Second, the incorporation of cationic quaternary ammonium moieties onto chitosan to enhance bacterial adsorption and antibacterial activity. Lastly, the reinforcement of mechanical properties through integration of cellulose fibers. The presented sponge materials exhibit up to a 4-log (99.99%) reduction within 6 h against both gram-positive B. subtilis and gram-negative E. coli. Notably, QCHI90/Cell, with the highest surface charge, exhibits a 2–4.5 log reduction within 1 h of incubation time. The eco-friendly synthesis from water and readily available biomaterials, along with cost-effectiveness and simplicity, underscores its versatility and feasibility of upscaling. Together with its outstanding antibacterial activity, this macroporous biomaterial emerges as a promising candidate for water disinfection applications.

Alkali Metal/Quaternary Ammonium Salt Synergistic Catalytic System for the Efficient Synthesis of Biobased Poly(Isosorbide Carbonate)

Alkali Metal/Quaternary Ammonium Salt Synergistic Catalytic System for the Efficient Synthesis of Biobased Poly(Isosorbide Carbonate)

Synthesis, characterization and antimicrobial evaluation of quaternary ammonium compounds from natural oils

Quaternary ammonium salts refer to any class of salt derived from ammonium in which the nitrogen atom is attached to four organic groups covalently, as in benzalkonium chloride (R4N+). Quaternary ammonium compounds were synthesized from Canola oil (Brasssicanapus) and Coconut oil (Cocos nucifera) extracts by reacting the oils with N,N-diethylethylenediamine in the presence of potassium tertiary butoxide as catalyst. Fourier Transform Infrared (FTIR) Spectrometric analyses of the starting materials, the intermediates and the final products were conducted, the results showed a disappearance of the carbonyl (C=O) stretch of an ester (the oil) at 1744cm-1 and appearance of N-H band of an amide at 3433cm-1, which resulted from the quaternization of benzyl chloride with the intermediates for both oils. Other functional groups such as C=C and C-H stretch of aromatic compound, C=O stretch of an amide were also observed.Mass spectrometric analysis of the final products were conducted and results showed the Molecular Ion peak (M+) which is the molecular weights of the products. Vital fragments such as base peaks were observed for both quats, other fragmented radical cations were observed.Antimicrobial activity of the synthesized Quaternary ammonium compounds (QACs) exhibited excellent anti-bacterial activity covering a diameter of 22 mm and 28 mm of E. coli for QACs from Cocos nucifera and Brassic anapus oils respectively as compared to the standard antibiotic (Ampillicin).

Membraneless channels sieve cations in ammonia-oxidizing marine archaea

Nitrosopumilus maritimus is an ammonia-oxidizing archaeon that is crucial to the global nitrogen cycle1,2. A critical step for nitrogen oxidation is the entrapment of ammonium ions from a dilute marine environment at the cell surface and their subsequent channelling to the cell membrane of N. maritimus. Here we elucidate the structure of the molecular machinery responsible for this process, comprising the surface layer (S-layer), using electron cryotomography and subtomogram averaging from cells. We supplemented our in situ structure of the ammonium-binding S-layer array with a single-particle electron cryomicroscopy structure, revealing detailed features of this immunoglobulin-rich and glycan-decorated S-layer. Biochemical analyses showed strong ammonium binding by the cell surface, which was lost after S-layer disassembly. Sensitive bioinformatic analyses identified similar S-layers in many ammonia-oxidizing archaea, with conserved sequence and structural characteristics. Moreover, molecular simulations and structure determination of ammonium-enriched specimens enabled us to examine the cation-binding properties of the S-layer, revealing how it concentrates ammonium ions on its cell-facing side, effectively acting as a multichannel sieve on the cell membrane. This in situ structural study illuminates the biogeochemically essential process of ammonium binding and channelling, common to many marine microorganisms that are fundamental to the nitrogen cycle.

Synthesis and characterization of cationic tamarind seed polysaccharide: An effective flocculating agent

A series of cationic tamarind seed polysaccharides (CTSPs) with different degrees of substitution were synthesized by etherification of tamarind seed polysaccharides (TSP) with 3-chloro-2-hydroxypropyl trimethylammonium chloride (CHPTAC). By elemental analysis, zeta potential and FTIR, the successful linking of cationic groups on the chain of TSPs were confirmed, and the substitution degrees were determined as 0.143, 0.197 and 0.346, respectively. NMR data indicated that the quaternary ammonium groups were linked to C6 of T-Gal. Subsequently, the flocculation behaviors of CTSPs in kaolin solution were investigated, and the results showed that both the degree of substitution and pH affected their flocculation properties. Charge neutralization and positional blocking effects caused flocculation to show an increasing and then decreasing trend with increasing substitution of CTSPs, whereas the lower the pH, the less flocculant was required to achieve the same flocculation effect. The presence of positive charges allowed CTSPs to effectively remove negatively charged waste water such as kaolin suspensions.

Electron Structure of α‐, β‐Te2MoO7 and Photocatalytic Decomposition of Antibiotics

AbstractTwo modifications of Te2MoO7 oxide have been prepared by different synthetic methods. The crystal structure and composition have been studied by X‐ray diffraction analysis and X‐ray microanalysis. The phase of α‐Te2MoO7 has been synthesized by solid‐state reaction from ammonium salts and characterized by monoclinic structure with P21/c. The β‐Te2MoO7 compound has been formed in hydrothermal conditions and has amorphous nature. The thermal behavior of β‐Te2MoO7 modification is characterized by the phase transition into α‐form, however after melting the amorphous state has restored. The electron structure has been investigated experimentally by X‐ray photoelectron spectroscopy and UV‐vis diffusion reflectance spectra and theoretically by approximation using atomic electronegativity. Despite the same composition, the band gap of β‐Te2MoO7 corresponds to visible light, whereas α‐Te2MoO7 adsorbs light in UV region. The both modifications are able to generate superoxide radicals in vacuum or air and hydroxyl radicals in water under irradiation. The HPLC‐MS analysis has shown the quite deep decomposition of dye and antibiotics by α‐Te2MoO7, whereas amorphous phase almost does not lead to any oxidation.

Different Fracture Liquids under the Action of Enclosure of Dense Sandstone Reservoir Micro-Damage Characteristics Study

The sandstone reservoir in the Lule River group of Mahai East District is strong, densely dense, and the expansion of clay material is very easy to block the pores. Therefore, the new pressure cracks and cationic cluster stabilizers with double-season ammonium salt clay stabilizers are used. Experimental analysis is performed under the circumstances of the perimeter. Use nuclear magnetic real-time testing different fracture liquids to drive the pore structure structure changes before and after the sandstone, combined with differential theory to calculate the fractal dimensions of sandstone. As a result, under the condition of water full, as the perimeter pressure increases, the rocks are increased, and the rocks are increased, and the rocks are increased. The matrix occurs under the common action of the fence and the fracture fluid to prevent the inflation of clay minerals under the combined action of the fence and the fracture fluid, which causes a significant reduction in large holes and increased micropores and medium holes. Exploring different fracture liquids to reservoirs is of great significance to the development of dense sandstone reservoirs.

Lignocellulosic waste biosorbents infused with deep eutectic solvents for biogas desulfurization

This paper introduces an innovative method for treating biogas streams, employing lignocellulosic biosorbents infused with environmentally friendly solvents known as deep eutectic solvents (DES). The primary focus of this study was the elimination of volatile organosulfur compounds (VSCs) from model biogas. Biosorbents, including energetic poplar wood, antipka tree, corncobs, and beech wood, were used, each with varying levels of lignin and hemicellulose content. The selection of the DES with the greatest potential for VSC removal was carried out using COnductor-like Screening MOdel for Realistic Solvents (COSMO-RS) modeling. The chosen DES consisted of quaternary ammonium salts and glycols, specifically, tetrapropylammonium bromide and 1,2-hexanediol (1:3). The physicochemical properties of the new DES, such as the viscosity, density, and melting point, were evaluated. The biosorbents were treated with the selected DES after shredding, purifying, and sieving. Comprehensive analysis techniques, including thermogravimetric analysis, scanning electron microscopy, and X-ray diffraction, were employed on the modified biosorbents both before and after modification. The subsequent step involved the adsorption of VSCs from biogas. The results of this study demonstrated the superior performance of a novel sorbent based on corn cob modified by DES compared to commercially available alternatives. The sorption capacity ranged from 103.8 to 112.1 mg/g for various VSCs. The adsorption process using the new biosorbent can be described by the pseudo second order kinetic model, as well as the Yoon-Nelson and Adams-Bohart models. The high efficacy of the VSCs removal was attributed to the concurrent operation of the absorption and adsorption processes. The resulting sorbent was also characterized by its ability to regenerate repeatedly without significant loss of sorption capacity of the new sorbents.

Effect of Argon in Nitrogen Gliding Arc Plasma for Ammonium Ions Enrichment in Water

Effect of Argon in Nitrogen Gliding Arc Plasma for Ammonium Ions Enrichment in Water

Double-skeleton interpenetrating network-structured alkaline solid-state electrolyte enables flexible zinc-air batteries with enhanced power density and long-term cycle life

The alkaline solid-state electrolytes have received widespread attention for their good safety and electrochemical stability. However, they still suffer from low conductivity and poor mechanical properties. Herein, we report the synthesis of double-network featured hydroxide-conductive membranes fabricated by polyvinyl alcohol (PVA) and chitosan (CS) as the double-skeletons. Then, we implanted quaternary ammonium salt guar hydroxypropyltrimonium chloride (GG) as the OH− conductor for high-performance electrochemical devices. By virtue of the unique stripe-like structure shared from the double skeleton with a high degree of compatibility and stronger hydrogen bond interactions, the polyvinyl alcohol/chitosan-guar hydroxypropyltrimonium chloride (PCG) solid-state electrolytes achieved optimal thermal stability (> 300 °C), mechanical property (∼ 34.15 MPa), dimensional stability (at any bending angle), and high ionic conductivity (13 mS cm−1) and ion mobility number (tion ∼ 0.90) compared with chitosan-guar hydroxypropyltrimonium chloride (CG) and polyvinyl alcohol-guar hydroxypropyltrimonium chloride (PG) electrolyte membrane. As a proof-of-concept application, the “sandwich”-type zinc-air battery (ZAB) assembled using PCG membrane as the electrolyte realized a high open-circuit voltage (1.39 V) and an excellent power density (128 mW cm−2). Notably, in addition to its long-term cycle life (30 h, 2 mA cm−2) and stable discharge plateau (12 h, 5 mA cm−2), it could even enable a flexible ZAB (F-ZAB) to readily power light-emitting diodes (LED) at any bending angle. These merits afford the PCG membrane a promising electrolyte for improving the performance of solid-state batteries.