Polyanetholesulfonic Acid Research Articles

Integrated computational approach towards identification of HSPG and ACE2 mimicking moieties for SARS-CoV-2 inhibition

A key step to inhibit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is to prevent the entry of the virus into the host cells. The receptor-binding domains (RBDs) of spike proteins of SARS-CoV and other human coronaviruses utilize heparan sulfate proteoglycans (HSPGs) as the primary receptors for their accumulation on the cell surface and then scan for binding to the main entry receptor angiotensin-converting enzyme 2 (ACE2). SARS-CoV and SARS-CoV-2 share structurally similar RBDs and therefore, it is possible that SARS-COV-2 primarily binds to HSPGs followed by binding to the ACE2 receptors. A promising strategy to inhibit virus infection is to circulate exogenous bioactive moieties structurally mimicking cellular HSPG and ACE2 which act as decoy receptors binding to SARS-CoV-2 and competitively inhibit virus entry to the host cells mediated by cellular-bound HSPG and ACE2. Using a molecular docking tool, we identified carboxymethyl benzyl amide sulfonate (CMBS) and polyanetholesulfonic acid (PAS) as the suitable HSPG mimicking ligands, and Paenibacillus sp. B38-derived carboxypeptidase (B38-CAP) and Bacillus subtilis-derived carboxypeptidase (BS-CAP) as the potential ACE2-like enzymes having a strong binding affinity to the spike proteins as that of cellular HSPG and ACE2. Further, the binding stability and compactness of these moieties with SARS-CoV-2 were analyzed through molecular dynamics (MD) simulations, and the results indicated that these moieties form well-stable complexes with the RBD of spike proteins. The identified moieties could be conjugated to the surfaces of non-toxic nanoparticles to provide multiple interactions to efficiently shield SARS-CoV-2, and inhibit viral entry to the host cells.

A STUDY OF CHROMIUM (VI) IONS FIXATION AND TRANSPORT USING POLYMER INCLUSION MEMBRANE CONTAINING D2EHPA AS COMPLEXING AGENT

In this paper, polymeric inclusion membranes (PIMs) containing cellulose triacetate (CTA) and polycaprolactone (PCL) as polymer matrix and di-(2-ethylhexyl) phosphoric acid (D2EHPA) as a specific carrier were prepared by solution casting followed by solvent evaporation. Different polymeric membranes were modified by the addition of polyelectrolytes: polyvinylpyrrolidone (PVP), polyanetholsulfonic acid (PATSA) and polyethylene imine (PEI). 2-Nitrophenyl octyl ether (NPOE) was added in the different membranes as plasticizer. All synthesized membranes were characterized by Fourier transform infrared (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). Transfer of chromium through selective membranes is accomplished by using a specific compound, called carrier. A study of the fixation and transport of Cr (VI) across a polymer inclusion membrane PIMs has shown a good removal from the treated solution. The Cr (VI) removal efficiency reached 42% after 8 hours of transport using the membrane containing (CTA + PCL + PATSA + D2EHPA) and 43% for only 2 hours using the membrane containing (CTA + PCL + PATSA+ NPOE).

Novel magnetic gel beads based on ionically crosslinked sodium alginate and polyanetholesulfonic acid: Synthesis and application for adsorption of cationic dyes

This study offers novel magnetic gel beads as an adsorbent containing bifunctional groups for cationic dye removal. The bifunctional composite gel beads were prepared from polyanetholesulfonic acid, alginate and magnetic zeolite (m-ALG/PESA), and characterized by FESEM-EDS, XRD, VSM, and TGA-FTIR. The adsorption capability of m-ALG/PESA beads was described using methylene blue (MB) and malachite green (MG). The maximum adsorption capacities of MB and MG onto m-ALG/PESA gel beads were 400 mg/g and 164 mg/g, respectively. Regeneration and reusability studies showed that both dyes were successfully desorbed from m-ALG/PESA gel beads with removal percentages approximately 90 in the first cycle and magnetic gel beads maintained their shapes after 10 times adsorption/desorption cycles in highly acidic conditions. It was also observed that MG was degraded during the desorption process. Therefore, the magnetic gel beads can be considered as a regenerable adsorbent making to the adsorption process is cost-effective and it is also biodegradable and environment-friendly material when used in pilot-scale applications.

Photo‐Electrodialysis Combination System for Cd2+ Removal Using Polymeric

The present work combines the solar energy with the environmental protection through the membrane selectivity for metallic ions. Firstly, we have elaborated new polymeric membranes for ions separation. The membrane is made up of cellulose acetate (CA) modified by polyelectrolytes (polyethylenimine (PEI), polyvinyl alcohol (PVA) and polyanetholsulfonic acid (PATSA) using glycerol as plasticizer. Different membranes are characterized by Fourier transform infrared spectroscopy (FTIR), X‐Ray diffraction (XRD), thermo‐gravimetric analysis (TGA) and scanning electron microscopy (SEM). In a second part, we have prepared two new photo‐electrodes, crystallizing in the brownmillerites structure: n‐Sr2Fe2O5 and p‐Sr2Co2O5 and their photo‐electrochemical characterizations are undertaken. As application, the transport of Cd2+ using the synthesized membranes coupled with the photo‐electrodes is studied. The photo‐catalytic results indicate that the combined hetero‐system n‐Sr2Fe2O5/p‐Sr2Co2O5 enhances considerably the electrons transfer. The diffusion flux of Cd2+ is considerably enhanced when the electrode is exposed to visible light illumination. The results show that the transport percentages of Cd2+ increases by 40% under solar energy and 25% under a tungsten lamp.

AIE-active polyanetholesulfonic acid sodium salts with room-temperature phosphorescence characteristics for Fe3+ detection

Room-temperature phosphorescent materials have been a major focus of research and development during the past decades, due to their applications in OLEDs, photovoltaic cells, chemical sensors, and bioimaging. However, achieving polymeric phosphorescent materials without heavy-metal atoms and halogens under ambient conditions remains a major challenge. Here, we report a polymeric phosphor, namely polyanetholesulfonic acid sodium salt, which not only has room temperature phosphorescence characteristic but also aggregation-induced emission and dependence on the excitation wavelength characteristics. Moreover, it can recognize Fe3+ effectively.

Heat effects measured in aqueous solutions of salts of poly(anethole sulfonic acid) upon mixing with alkali-, alkaline-earth-, and tetraalkylammonium chlorides

Abstract Experimental and theoretical results for the enthalpies of mixing, Δ mix H , for aqueous solutions of selected salts of polyanethole sulfonic acid with some low-molecular-mass salts are presented. The enthalpies of mixing for aqueous solutions of alkali (Li + , Cs + ) and tetraalkylammonium (Me 4 N + , Bu 4 N + ) polyanethole sulfonates (PAS − ) with alkali-metal chlorides (LiCl, KCl, CsCl) and tetraalkylammonium chlorides (Me 4 NCl, Et 4 NCl, Pr 4 NCl, Bu 4 NCl) were measured with an isothermal titration calorimeter at 298.15 K. The first two polysalts (LiPAS, CsPAS) were also titrated with MgCl 2 and SrCl 2 solutions. Manning's theory was used to predict the electrostatic contribution to the enthalpy of mixing for polyelectrolyte and simple electrolyte solutions. The observed differences between the experimental and calculated values were ascribed to the ion-specific interactions. The cumulative heat effects obtained from the titration of the poly(anethole sulfonic) salts with the alkali chlorides, including Me 4 NCl, for a molar ratio r = 4.6, decreased with the hydration enthalpy, ∆ hyd H , of the added counterions. In contrast to this, the enthalpies of mixing for poly(anethole sulfonic) salts with tetraalkylammonium chlorides increased with the length of the alkyl chain in the added counterion. The results show a strong dependence of the enthalpy of mixing on the difference in the nature of the counterions in the mixture. Additionally, the results allow us to classify the counterions as either hydrophilic or hydrophobic based on the heat effects provoked by their introduction into a polyelectrolyte solution.

The influence of impurity proteins on the precipitation of a monoclonal antibody with an anionic polyelectrolyte

In order to meet the growing demand for monoclonal antibodies (mAbs), many research studies focus on the development of new purification technologies to overcome disadvantages of conventional methods. The precipitation of mAbs with anionic polyelectrolytes is a promising alternative offering advantages like e.g. low additive consumption. The antibody–polyelectrolyte interaction depends on numerous factors. While the influence of factors like pH value, ionic strength and polyelectrolyte concentrations was already examined in different studies, this study focuses on the influence of different properties of impurity proteins on the precipitation of a monoclonal antibody with the anionic polyelectrolyte polyanetholesulfonic acid. For this purpose, five model impurity proteins, bovine serum albumin, ovalbumin, α-Lactalbumin, β-Lactoglobulin, and myoglobin, were selected with regard to their isoelectric points and molecular weights. Additionally, the surface charge distribution of these proteins was simulated. The experimental results provide a better insight in the electrostatic interactions taking place between proteins and polyelectrolyte molecules.

Salt Effect on Osmotic Pressure of Polyelectrolyte Solutions: Simulation Study

Abstract: We present results of the hybrid Monte Carlo/molecular dynamics simulations of the osmotic pressure of salt solutions of polyelectrolytes. In our simulations, we used a coarse-grained representation of polyelectrolyte chains, counterions and salt ions. During simulation runs, we alternate Monte Carlo and molecular dynamics simulation steps. Monte Carlo steps were used to perform small ion exchange between simulation box containing salt ions (salt reservoir) and simulation box with polyelectrolyte chains, counterions and salt ions (polyelectrolyte solution). This allowed us to model Donnan equilibrium and partitioning of salt and counterions across membrane impermeable to polyelectrolyte chains. Our simulations have shown that the main contribution to the system osmotic pressure is due to salt ions and osmotically active counterions. The fraction of the condensed (osmotically inactive) counterions first increases with decreases in the solution ionic strength then it saturates. The reduced value of the system osmotic coefficient is a universal function of the ratio of the concentration of osmotically active counterions and salt concentration in salt reservoir. Simulation results are in a very good agreement with osmotic pressure measurements in sodium polystyrene sulfonate, DNA, polyacrylic acid, sodium polyanetholesulfonic acid, polyvinylbenzoic acid, and polydiallyldimethylammonium chloride solutions.

Single-step microfluidic synthesis of various nonspherical polymer nanoparticles via in situ assembling: dominating role of polyelectrolytes molecules.

In this paper, a microfluidic approach has been used for the synthesis of ellipsoidal, dumbbell, rodlike, and necklacelike polymer nanoparticles. High yields of special types of nonspherical nanoparticles have been achieved by the implementation of an emulsion polymerization into microfluidic arrangement with a micro hole-plate reactor for the formation of monomer droplets. Here, in particular, the formation of nonspherical polymer nanoparticles is dependent on the presence of polyelectrolyte surface active molecules such as poly(4-styrenesulfonic acid-co-maleic acid) sodium salt (PSS-co-PM), poly(sodium-p-styrenesulfonate) (PSSS), and polyanetholesulfonic acid sodium salt (PAES). The shapes and sizes of the interparticle nanoassemblies are precisely controlled by adjusting the concentration of polyelectrolytes in the aqueous phase, and by choosing suitable flow rate ratios (aqueous to monomer phase), respectively. The formation of polymer nanoparticles with different morphologies can be explained by a spontaneous in situ assembling under partial electrostatic repulsive control in the single step synthesis. The effect of particle charge and the competition between thermal motion of particles and electrostatic repulsion on the spontaneous assembling under the condition of a limited polarizability are discussed here as an important factor for the formation process of nonspherical polymer nanoparticles.

Identification of parameter interactions influencing the precipitation of a monoclonal antibody with anionic polyelectrolytes

There is a constantly growing demand for monoclonal antibodies for therapeutic and diagnostic applications. Due to this trend the development of new and cost-efficient purification methods is of high importance. This study investigates the separation of a monoclonal antibody from model impurity bovine serum albumin using anionic polyelectrolytes. Different types and molecular weights of anionic polyelectrolytes were screened for their applicability as precipitation agents. Polyanetholesulfonic acid was identified as most promising candidate. Furthermore, the influence and interactions of various parameters on antibody precipitation were investigated by means of Design of Experiments. Design of Experiments provided a fast identification of influencing parameters and parameter interactions. The strongest influence on yield and selectivity of precipitation showed the polyelectrolyte concentration and its interaction with the pH value and the sodium chloride and bovine serum albumin concentration. The interactions identified showed, that parameters should be investigated and optimized together, not stand-alone.

Synthesis of modified polymer inclusion membranes for photo-electrodeposition of cadmium using polarized electrodes

In this work, we have developed a novel class of polymeric inclusion membranes (PIMs) for the cations separation. The membrane is made up of cellulose triacetate modified by poly-electrolytes (poly-phosphoric acid, polyvinyl pyrolidone, polyacrylic acid, polyvinyl alcohol and poly-anetholsulfonic acid) using 2-hydroxy-5-dodecylbenzaldehyde incorporated into the polymer as carrier and tris ethyl hexyl phosphate or glycerine as plasticizers. Different PIMs are synthesized and characterized by the Fourier transform infrared, X-ray diffraction, thermal analysis and scanning electron microscopy. The influence of the membrane nature is studied using supports with different physical characteristics (porosity, thickness, hydrophobia). As application, the transport of Cd2+ using PIMs coupled with photo-electrodes is investigated.The photo-catalytic results indicate that the combined system p-CuFeO2/membrane/n-WO3 enhances considerably the electrons transfer toward the delafossite CuFeO2.The position of the conduction band of CuFeO2 is looked to be the key issue for the photo electrochemical Cd2+ reduction.

The proteoglycan osteoglycin/mimecan is correlated with arteriogenesis

Arteriogenesis or collateral growth is able to compensate for the stenosis of major arteries. Using differential display RT-PCR on growing and quiescent collateral arteries in a rabbit femoral artery ligation model, we cloned the rabbit full-length cDNA of osteoglycin/mimecan. Osteoglycin was present in the adventitia of collateral arteries as a glycosylated protein without keratan sulfate side chains, mainly produced by smooth muscle cells (SMCs) and perivascular fibroblasts. Northern blot, Western blot, and immunohistochemistry confirmed a collateral artery-specific downregulation of osteoglycin from 6 h to 3 weeks after the onset of arteriogenesis. Treatment of primary SMCs with the arteriogenic protein fibroblast growth factor-2 (FGF-2) resulted in a similar reduction of osteoglycin expression as observed in vivo. Application of the FGF-2 inhibitor polyanethole sulfonic acid (PAS) blocked the downregulation of osteoglycin and interfered with arteriogenesis. From our study we conclude that downregulation of osteoglycin is a fundamental requirement for proper arteriogenesis.

Kinetic methods for determining water-soluble polymers

The effect of synthetic water-soluble polymers on the reactions of hydroquinone or 3,3′,5,5′-tetramethylbenzidine periodate oxidation with hydrogen peroxide is studied. A polymer solution was introduced into the reaction and a change in its rate was detected by photometry. Possible reasons for the effect of polymers are discussed, the role of the positive and negative charges of the polymeric chain and the nature of the indicator reaction are considered. The possibility of determining polyelectrolytes by their accelerating and inhibiting effect is demonstrated, including that, under the conditions of polyelectrolyte complex formation, and also by binding with a metal ion catalyzing the indicator reaction. Procedures are proposed for the simple and rapid determination of 3,6-ionene, polyanetholesulfonic acid, polyhexamethyleneguanidine (∼10−5 to 10−4 M, in terms of the monomer), polyethyleneimine and chitosans (∼10−7−10−6 M in terms of the monomer) in aqueous solutions, and also of polyethyleneimine by carrying out the indicator reaction on a silica surface (4 × 10−6 to 0.7 M in terms of the monomer).

Polyelectrolyte hydration: Theory and experiment

AbstractA short review of recent theoretical and experimental advances in studies of polyelectrolyte solutions is presented. The focus is on ion-specific effects as revealed in measurements of osmotic pressure and enthalpy of dilution. We review the experimental results for two different polyelectrolyte systems: (i) salts of polyanetholesulfonic acid, and (ii) aliphatic ionenes (polycations) in aqueous solution with various counterions. A theoretical approach based on the extension of Wertheim's integral equation theory [J. Stat. Phys.35, 19 (1984)] is used to analyze the experimental data. Preliminary results, based on the all-atom simulation of model 3,3 ionene oligomers, are discussed in the light of polyelectrolyte hydration.

Thermodynamic Characterization of Polyanetholesulfonic Acid and Its Alkaline Salts

Experimental and theoretical results for the thermodynamic properties of polyanetholesulfonic acid and its lithium, sodium, and cesium salts in aqueous solution at 298 K are presented. The osmotic pressure was measured using membrane and vapor pressure apparatus in the concentration range c(m) = 0.001-0.30 monomoles/dm(3). The osmotic coefficients obtained from these measurements were low, from 0.2 to 0.45 in this concentration range, indicating a strong interaction between counterions and polyions. The osmotic coefficients of the polyacid and its lithium and sodium salts appeared to be equal within experimental error, but the results for the cesium salt were lower. This indicates a somewhat stronger binding of cesium ions to the polyanion. In addition, enthalpies of dilution, DeltaH(D), from a certain concentration, m(m), to m(m) = 0.0044 monomoles/kg were measured. The measured heats of dilution were exothermic, with the acid producing the strongest and the cesium salt the weakest effect. These results were compared with previously published data for polyelectrolytes of similar structure, namely, polystyrenesulfonic acid and its alkaline salts. The osmotic pressure results indicate that polystyrenesulfonates bind the counterions more strongly than polyanetholesulfonic acid and its salts. Consistent with this finding, the enthalpies of dilution reveal that more heat is released upon dilution of polyanetholesulfonates (stronger exothermic effect) in comparison with the corresponding solutions of polystyrenesulfonic acid in its alkaline salts. These findings can be explained in terms of the structural differences between the two polyions. The experimental results were analyzed in relation to popular electrostatic theories such as the Manning condensation theory and the Poisson-Boltzmann cell model approach, where the polyion is pictured as a uniformly charged line or cylinder. In addition, we performed Monte Carlo simulations for a model polyanetholesulfonic anion having discrete charges. In all of the calculations, the solvent was treated as a continuum with the dielectric constant of pure water under the conditions of measurement. The theoretical considerations mentioned above yield results in semiquantitative agreement with the measured quantities.

Involvement of the Fibroblast Growth Factor System in Adaptive and Chemokine-Induced Arteriogenesis

Fibroblast growth factors (FGFs) have been applied in a variety of therapeutic and experimental studies to improve collateral blood flow. However, the pathophysiological role and the temporospatial expression of the FGFs and their receptors during arteriogenesis have never been elucidated in vivo. Here, we report that collateral artery growth in its early phase is associated with an increased expression of FGF receptor-1 (FGFR-1) and syndecan-4 on mRNA and protein levels as well as with an increased kinase activity of FGFR-1 in a rabbit model of arteriogenesis. However, the mRNA levels of FGF-1 and -2 remained constant. Our data suggest that these growth factors are supplied by endothelial attracted monocytes that, in turn, produce and deliver the FGFs to growing collateral arteries. Monocyte chemoattractant protein-1-stimulated arteriogenesis was strongly reduced in rabbits by application of the FGF inhibitor polyanetholesulfonic acid, indicating that the monocyte-related arteriogenesis (as well as the unstimulated adaptation proper) is promoted by FGFs. In summary, this study shows that arteriogenesis is associated with an increased expression of the FGFRs at the site of the vessel, whereas the growth-promoting ligands are supplied by monocytes in a paracrine way.

Osmotic coefficients of polyelectrolyte solutions, measurements and correlation

Osmotic coefficient data for aqueous sodium polyanetholesulfonic acid, sodium polyacrylate and polydiallyl dimethylammonium chloride solutions were determined at 298 K by employing the isopiestic method. The measured osmotic coefficients increase with increasing concentration in the experimental concentration range (0.1–1.5 m). A molecular thermodynamic model developed previously for polyelectrolyte solutions has been used to fit the experimental data. The concentration dependence of the osmotic coefficients can be described satisfactorily.

Reversible binding of heparin to the loop peptide of endotoxin neutralizing protein.

Endotoxin neutralizing protein (ENP) from Limulus polyphemus is an amphipathic, 11.8 kDa protein with an isoelectric point of 10.2. ENP neutralizes lipopolysaccharide (LPS) and possesses antibacterial activity against Gram-negative bacteria. Heparin binds to ENP and blocks its LPS-neutralizing activity. The relative blocking activity of heparin is equal to low molecular weight heparin and polyanetholsulfonic acid > heparan sulfate > chondroitin sulfate A > chondroitin sulfate C. Endoproteinase Glu-C hydrolysis of recombinant ENP results in four major peptides, three of which are seen following separation on reversed phase HPLC. Heparin binds to the loop peptide (31-72), which includes the heparin binding consensus sequence XBBXBX between the two cysteine residues of ENP. When heparin is added to the digest and then applied to a C18 column, the loop peptide is bound; however, it dissociates and elutes with either 5 M NaCl or 0.1 M sodium phosphate, demonstrating reversible binding to heparin. LPS and lipid A both bind to the loop peptide and remove it from digests of ENP; however, neither complex could be dissociated by salt or sodium phosphate. Heparin, LPS, and lipid A individually bind to the same site on ENP.

Adherence of Mycoplasma pneumoniae to human alveolar macrophages

The human pathogen Mycoplasma pneumoniae causes primary atypical-cold agglutinin-positive pneumonia. Since alveolar macrophages internalize mycoplasma as part of their immune defense, we studied characteristics of the human macrophage receptor for opsonized and nonopsonized M. pneumoniae. The glass-adhering subpopulation of M. pneumoniae attached more than the non-adherent subpopulation. The attachment was dose-dependent and enhanced by opsonization in the presence of human serum. It is inhibited by sulfated compounds such as dextran-sulfate and polyanetholsulfonic acid, but not by dextran or several monosaccharides, suggesting that sulfated glycolipids on the macrophage surface may act as receptors for M. pneumoniae binding. In addition, sialylated compounds, such as fetuin and α 1-acid glycoprotein, were found to be potent inhibitors of the attachment, also indicating the role of sialic acid residue in recognition and attachment of M. pneumoniae to human alveolar macrophages.

Adherence of Mycoplasma pneumoniae to human alveolar macrophages.

The human pathogen Mycoplasma pneumoniac causes primary atypical-cold agglutinin-positive pneumonia. Since alveolar macrophages internalize mycoplasma as part of their immune defense, we studied characteristics of the human macrophage receptor for opsonized and nonopsonized M. pneumoniae. The glass-adhering subpopulation of M. pneumoniae attached more than the non-adherent subpopulation. The attachment was dose-dependent and enhanced by opsonization in the presence of human serum. It is inhibited by sulfated compounds such as dextran-sulfate and polyanetholsulfonic acid, but not by dextran or several monosaccharides, suggesting that sulfated glycolipids on the macrophage surface may act as receptors for M. pneumoniae binding. In addition, sialylated compounds, such as fetuin and alpha 1-acid glycoprotein, were found to be potent inhibitors of the attachment, also indicating the role of sialic acid residue in recognition and attachment of M. pneumoniae to human alveolar macrophages.