Alkylpyridinium Salts Research Articles

Evaluation of the antifouling properties of 3-alyklpyridine compounds

One of the most promising alternative technologies to antifouling (AF) biocides based on toxic heavy metals lies in the development of natural eco-friendly biocides. The present study evaluates the AF potential of structurally different compounds containing a 3-alkylpyridine moiety. The products, namely poly 3-alkylpyridinium salts, saraine, and haminols, were either extracted or derived from natural sources (the sponges Haliclona sp. and Reniera sarai and the mollusc Haminoea fusari), or obtained by chemical synthesis. All the molecules tested showed generally good anti-settlement activity against larvae of the barnacle Amphibalanus (=Balanus) amphitrite (EC50 values between 0.19 and 3.61 μg ml−1) and low toxicity (LC50 values ranging from 2.04 to over 100 μg ml−1) with non-target organisms. For the first time, the AF potential of a synthetic monomeric 3-alkylpyridine was demonstrated, suggesting that chemical synthesis is as a realistic way to produce large amounts of these compounds for future research and development of environmentally-friendly AF biocides.

ChemInform Abstract: Nucleophilic Addition of 2-Indolylacyl Anion Equivalents to N- Alkylpyridinium Salts.

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Njaoaminiums A, B, and C: Cyclic 3-Alkylpyridinium Salts from the Marine Sponge Reniera sp.

Three novel cyclic 3-alkylpyridinium salts, named njaoaminiums A, B, and C (1-3), were isolated from the marine sponge Reniera sp., collected off the coasts of Pemba Island, Tanzania. The structural determination of the compounds was based on 1D and 2D NMR studies and mass spectral determinations. Njaoaminiums B (2) and C (3) are the first examples of cyclic 3-alkylpyridinium salts bearing a methyl substituent on the alkyl chains. These compounds are assumed to be biosynthetic precursors of the njaoamines, previously isolated from the same sponge. The absolute configurations of the methyls of 2 and 3 were assigned by comparison between experimental and TDDFT calculated circular dichroism spectra on the most stable conformer. Compound 2 showed weak cytotoxicity against the three human tumor cell lines MDA-MB-231, A549, and HT29.

Cardiotoxic activity of polymeric 3-alkylpyridinium salts from the marine sponge Reniera sarai

Background Marine sponges are a rich source of novel biologically active substances such as haemolytic proteins, hemagglutinins and proteins with antimicrobial, antiviral and antifungal activity. Toxic water-soluble polymeric 3alkylpyridinum salts (poly-APS) have been isolated from the marine sponge Reniera sarai. Poly-APS has pore-forming properties expressed in a dose-dependent manner. These interactions with cell membranes results in increased Ca2+ permeability. In in vivo experiments performed in rats, poly-APS caused transient bradycardia, prolongation of expirium, lowered blood pressure, formed numerous thrombocyte aggregates and caused death. The aim of the present study was to investigate the direct cardiotoxic effects of poly-APS on isolated rat hearts.

Thermodynamic study of the process of micellization of long chain alkyl pyridinium salts in aqueous solution

Abstract The molality dependence of specific conductivity of pentadecyl bromide, cetylpyridinium bromide and cetylpiridinium chloride in aqueous solutions has been studied in the temperature range of 30–45 °C. The critical micelle concentration (cmc) and ionization degree of the micelles, β, were determined directly from the experimental data. Thermal parameters, such as standard Gibbs free energy \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\Updelta G_{m}^{0} ,$$ \end{document} enthalpy \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace...

3-Alkylpyridinium salts from Haplosclerida marine sponges: Isolation, structure elucidations, and biosynthetic considerations

Abstract A very little studied marine sponge Callyspongia sp. collected off the coast of Martinique was chemically investigated. The study led to the isolation and structure characterization of two new 3-alkylpyridinium salts which belonged to the recently isolated pachychaline family. Structures were elucidated by 1D, 2D NMR and detailed high-resolution electron spray ionization mass spectra (HRESIMS)-MS studies. The use of HRESIMS-MS studies proved to be highly efficient to identify two other close derivatives in a mixture. Finally, these studies allowed us to propose a general biosynthetic pathway leading to important 3-alkylpyridinium salts.

Synthesis and exfoliation of alkyl-pyridinium/Bi2212 nanohybrids

Nanohybrids of superconducting Bi2Sr2CaCu2O8+d (Bi2212) with alkyl-pyridinium salts were synthesized by a stepwise intercalation method. HgBr2 was intercalated into Bi2212 crystal to prepare a precursor before intercalation of alkyl-pyridinium ions. Alkyl-pyridinium (Py-CnH2n+1, where Py = pyridine and n = 4, 12 and 16) was adopted as guest intercalants. Nanohybrids were characterized by X-ray powder diffraction. It is found that the gallery height of Bi2212 host is expanded from 3.07 nm to 8.69 nm (Δc = 5.61 nm) in Py-C16H33/Bi2212. We were successful in preparing transparent colloid of Py-C16H33/Bi2212 nanohybrid in organic solvent. This colloid is found to be stable for 6 days. Ultrathin films assembled by the layer-by-layer technique from Bi2212 colloids with a cationic polymer were fabricated.

Identification of Metabolites Involved in the Biodegradation of the Ionic Liquid 1-Butyl-3-methylpyridinium Bromide by Activated Sludge Microorganisms

Ionic liquids (ILs) are low melting organic salts that potentially comprise wide application due to their fascinating properties and have emerged as promising "green" replacements for volatile organic solvents. Despite their nonmeasurable vapor pressure, some quantities of ILs will soon be present in effluent discharges since they do have significant solubility in water. Recently, the toxic effects of ILs toward aquatic communities have been intensively investigated, but little information is available concerning the biodegradable properties of these compounds. The objective of this study was to identify the metabolites generated during the biotransformation of 1-butyl-3-methylpyridinium by microorganisms in aerobic activated sludge. The obtained results revealed that the alkylpyridinium salt was metabolized through the sequential oxidization in different positions of the alkyl side chains. High-performance liquid chromatography and mass-spectrometry analyses demonstrated that this biodegradation led to the formation of 1-hydroxybutyl-3-methylpyridinium, 1-(2-hydroxybutal)-3-methylpyridinium, 1-(2-hydroxyethyl)-3-methylpyridinium, and methylpyridine. On the basis of these intermediate products, biodegradation pathways were also suggested. These findings provide the basic information that might be useful for assessing the factors related to the environmental fate and behavior of this commonly used pyridinium IL.

Induction of fruiting in oyster mushroom ( Pleurotus ostreatus) by polymeric 3-alkylpyridinium salts

Polymeric 3-alkylpyridinium salts (poly-APS), surface-active compounds from the marine sponge Reniera sarai, have been shown to stimulate the fruit body formation from Pleurotus ostreatus mycelium. In nutrient media supplemented with poly-APS (≥0.01 μg ml −1), the formation of primordia and development of fruit bodies were detected approximately 10 d earlier than in the absence of poly-APS, and also led to a considerably larger quantity of young mushrooms. This effect appears to be specific, as other surface-active compounds, lysophospholipids and fatty acids, showed no induction of fruiting.

Influence of polymeric 3-alkylpyridinium salts from the marine sponge Reniera sarai on the growth of algae and wood decay fungi

Polymeric alkylpyridinium salts (poly-APS) isolated from the marine sponge Reniera sarai act as antifouling and anticholinesterase agents. They also show moderate haemolytic and cytotoxic activities against different cell lines. The haemolytic activity of poly-APS is due to their detergent-like structure and behaviour in aqueous solutions. In this work, the lytic activity of poly-APS against freshwater and marine algae, and inhibitory effects on wood decay fungi, were investigated. The results show that poly-APS inhibit the proliferation and movements of susceptible algae. Effects of poly-APS were time- and concentration-dependent and differed between various algal species. No growth inhibition effects were observed towards the examined wood fungi.

Reaction of Aldimine Anions with Vinamidinium Chloride: Three-Component Access to 3-Alkylpyridines and 3-Alkylpyridinium Salts and Access to 2-Alkyl Glutaconaldehyde Derivatives

N-tert-Butylimino derivatives of aldehydes were deprotonated with LDA and reacted with vinamidinium chloride to give 2-alkylaminopentadienimine derivatives, which were isolated as their corresponding hydrochloride in 68-81% yield. Reaction of these derivatives with ammonium acetate or salts of primary amines, in n-butanol at 80 degrees C, afforded the corresponding 3-alkylpyridines or 3-alkylpyridinium salts in high yield. Alkaline hydrolysis of 2-alkylaminopentadieneimine derivatives allowed a practical accesss to potassium salts of 2-alkylglutaconaldehyde.

Mechanisms of Toxicity of 3-Alkylpyridinium Polymers from Marine Sponge Reniera sarai

Polymeric 3-alkylpyridinium salts (poly-APS) present in the marine sponge Reniera sarai show a broad spectrum of biological activities. They are lytic to erythrocytes and various other mammalian cells, enabling the transfection of the latter with alien DNA. Furthermore, they show inhibitory effects to marine bacteria and can inhibit fouling of micro- and macroorganisms to submerged surfaces. Finally, poly-APS act as potent cholinesterase inhibitors. The kinetics of acetylcholinesterase inhibition by poly-APS in vitro is complex and comprises several successive phases ending in irreversible inhibition of the enzyme. The latter is accounted for by aggregation and precipitation of the enzyme-inhibitor complexes. Poly-APS are lethal to rats in concentrations above 2.7 mg/kg. Monitoring of the basic vital functions and histopathological analysis showed that the effects directly ascribable to acetylcholinesterase inhibition are only observed after application of lower concentrations of poly-APS. At higher concentrations, such effects were masked by other, more pronounced and faster developing lethal effects of the toxin, such as haemolysis and platelet aggregation.

A comparative study of the actions of alkylpyridinium salts from a marine sponge and related synthetic compounds in rat cultured hippocampal neurones

BackgroundPolymeric alkylpyridinium salts (poly-APS), are chemical defences produced by marine sponges including Reniera sarai. Poly-APS have previously been shown to effectively deliver macromolecules into cells. The efficiency of this closely follows the ability of poly-APS to form transient pores in membranes, providing strong support for a pore-based delivery mechanism. Recently, water soluble compounds have been synthesised that are structurally related to the natural polymers but bear a different number of pyridinium units. These compounds may share a number of bio-activities with poly-APS. Using electrophysiology, calcium imaging and 1,6-diphenyl-1,3,5-hexatriene imaging, the pore forming properties of poly-APS and four related synthetic oligomers have been tested on primary cultured rat hippocampal neurones.ResultsAcute application of poly-APS (0.5 μg/ml), reduced membrane potential, input resistance and suppressed action potential firing. Poly-APS evoked inward cation currents with linear current-voltage relationships similar to actions of pore formers on other cell types. Poly-APS (0.005–5 μg/ml) also produced Ca2+ transients in ~41% of neurones. The dose-dependence of poly-APS actions were complex, such that at 0.05 μg/ml and 5 μg/ml poly-APS produced varying magnitudes of membrane permeability depending on the order of application. Data from surface plasmon resonance analysis suggested accumulation of poly-APS in membranes and subsequent enhanced poly-APS binding. Even at 10–100 fold higher concentrations, none of the synthetic compounds produced changes in electrophysiological characteristics of the same magnitude as poly-APS. Of the synthetic oligomers tested compounds 1 (monomeric) and tetrameric 4 (5–50 μg/ml) induced small transient currents and 3 (trimeric) and 4 (tetrameric) produced significant Ca2+ transients in hippocampal neurones.ConclusionPoly-APS induced pore formation in hippocampal neurones and such pores were transient, with neurones recovering from exposure to these polymers. Synthetic structurally related oligomers were not potent pore formers when compared to poly-APS and affected a smaller percentage of the hippocampal neurone population. Poly-APS may have potential as agents for macromolecular delivery into CNS neurones however; the smaller synthetic oligomers tested in this study show little potential for such use. This comparative analysis indicated that the level of polymerisation giving rise to the supermolecular structure in the natural compounds, is likely to be responsible for the activity here reported.

Mechanisms of Toxicity of 3-Alkylpyridinium Polymers from Marine Sponge Reniera sarai

Polymeric 3-alkylpyridinium salts (poly-APS) present in the marine spongeReniera sarai show a broad spectrum of biological activities. They are lytic to erythrocytesand various other mammalian cells, enabling the transfection of the latter with alien DNA.Furthermore, they show inhibitory effects to marine bacteria and can inhibit fouling ofmicro- and macroorganisms to submerged surfaces. Finally, poly-APS act as potentcholinesterase inhibitors. The kinetics of acetylcholinesterase inhibition by poly-APS invitro is complex and comprises several successive phases ending in irreversible inhibitionof the enzyme. The latter is accounted for by aggregation and precipitation of the enzyme-inhibitor complexes. Poly-APS are lethal to rats in concentrations above 2.7 mg/kg.Monitoring of the basic vital functions and histopathological analysis showed that theeffects directly ascribable to acetylcholinesterase inhibition are only observed afterapplication of lower concentrations of poly-APS. At higher concentrations, such effectswere masked by other, more pronounced and faster developing lethal effects of the toxin,such as haemolysis and platelet aggregation.

Marine sponge-derived polymeric alkylpyridinium salts as a novel tumor chemotherapeutic targeting the cholinergic system in lung tumors

Previous studies have shown that the cholinergic system plays a pivotal rule in small cell lung cancer (SCLC) cell growth through an autocrine loop that activates the nicotinic cholinergic receptor, which together with the activation of this receptor by nicotine links SCLC evolution with tobacco use. Non-small cell lung cancer (NSCLC) is the most common form of lung cancer and is also linked to tobacco use. Here we describe the presence of molecules of the cholinergic system in NSCLC samples and cell lines and investigate the implications of the cholinergic system in cell growth regulation. Cholino-acetyltransferase (ChAT), vesicular acetylcholine transporter (VAChT) and acetylcholinesterase (AChE) were observed in NSCLC tumor biopsies and in NSCLC cell lines. Polymeric alkylpyridinium salts (poly-APS) are AChE inhibitors isolated from the crude extract of the marine sponge, Reniera sarai. These metabolites were characterized as a mixture of two polymers of 3-octylpyridinium, including 29 and 99 monomeric units. Exposure of normal lung fibroblast and NSCLC cell lines to poly-APS revealed a selective cytotoxicity for cancer cells as compared to the normal fibroblast cell lines. FACS analysis indicated poly-APS induced apoptosis in NSCLC cells but not in normal lymphocytes. Non-toxic doses of poly-APS also potently reduced NSCLC cell-cell adhesion in suspension cultures. The limited toxicity of poly-APS on normal cells was confirmed by injection in the caudal vein of mice. No overt effects on health parameters, such as weight gain and physical behavior, were observed, and histological analysis of major organs did not reveal differences between the treated animals as compared to controls. These data demonstrate that NSCLC cells express cholinergic molecules that may be involved in cell growth regulation and that the cholinesterase inhibitor, poly-APS, shows selective toxicity toward NSCLC cells while having no apparent toxicity towards normal cells and tissue in vitro and in vivo.

Comparative antibacterial activity of polymeric 3-alkylpyridinium salts isolated from the Mediterranean sponge Reniera sarai and their synthetic analogues

Metabolites from marine sponges are considered a promising alternative to heavy metals in antifouling coatings. Water-soluble polymeric 3-alkylpyridinium salts and 14 related synthetic analogues showed considerable antibacterial activity against marine biofilm bacteria and may represent good candidates as natural biocides for marine technology applications.

Growth of TiO2 nanocrystals in the presence of alkylpyridinium salts: the interplay between hydrophobic and hydrophilic interactions

AbstractTiO2 nanoparticles were prepared by combining a sol–gel precipitation with growth steps performed in the presence of cationic surfactants, dodecylpyridinium chlorides (DPC), and cetylpyridinium chlorides (CPC). Solutions at concentrations pertaining to the existence of either surfactant monomers or aggregates (micelles) were employed. XPS analyses were performed both on the surfactant salts and on the aged, dried precursors to study the surfactant films adsorbed onto the oxide. The crystal structures of the calcined samples and the phase composition were examined by X‐ray diffraction. The role played by the presence of the surfactant in affecting the physicochemical properties of the powders is discussed. Copyright © 2006 John Wiley & Sons, Ltd.

Sphere to rod transitions in homologous alkylpyridinium salts: A Stauff-Klevens-type equation for the second critical micelle concentration

In the present paper, we analyze the dependence of the second critical micelle concentration (second cmc) of ionic amphiphiles on the number of atoms in the hydrocarbon molecular chain, n c . A molecular thermodynamic model for the interaction energy between the end caps of rodlike micelles, g ( N ) , is introduced and the linear dependence of this object on n c analyzed, thus leading to a Stauff-Klevens-like behavior of the second cmc. The predictions agree with previously reported data for n-alkyldimethylbenzylammonium chloride (C n BACl) for n-alkylpyridinium chloride (C n PyCl) and n-alkyltrymethylammonium bromide (C n TABr) at 35 °C. These conclusions are reinforced by the conductivity, density, and ultrasound velocity measurements of the second cmc of several C n PyCl ( n = 12 , 14, 16) and n-alkylpyridinium bromides (C n PyBr, n = 12 , 14, 15, 16) presented in this paper.

Electrochemically driven organic monolayer formation on silicon surfaces using alkylammonium and alkylphosphonium reagents

The functionalization of silicon surfaces with organic monolayers, bound through Si–C bonds, is an area of wide interest due to the technological promise of organosilicon hybrid devices, but also to investigate fundamental surface reactivity. In this paper, the use of alkylammonium and alkylphosphonium cations as sources of organic moieties to bind to hydrogen-terminated flat and porous silicon is demonstrated. Tetraalkylammonium, tetraalkyl/arylphosphonium reagents, and alkyl pyridinium salts can be utilized, but trialkylammonium salts cannot as they yield substantial surface oxidation. Under electrochemical conditions, either potentiostatic or galvanostatic modes, alkyl groups derived from the ammonium or phosphonium salts are grafted to the silicon surface and are bound through Si–C bonds. Covalent attachment of the organic monolayers to the surface was demonstrated by XPS, AFM scribing, and FTIR. The mechanism may proceed via reduction of the ammonium salt yielding alkyl radicals, R , which may be reduced to R − and attack surface Si–Si bonds, leading to Si–C bonds, or the formation of silyl anions (≡Si −) under the cathodic conditions followed by nucleophilic attack on the trialkylammonium cation.

Selective Complexation of N‐Alkylpyridinium Salts: Binding of NAD+ in Water

A new class of receptor molecules is presented that is highly selective for N-alkylpyridinium ions and electron-poor aromatics. Its key feature is the combination of a well-preorganized molecular clip with an electron-rich inner cavity and strategically placed, flanking bis-phosphonate monoester anions. This shape and arrangement of binding sites attracts predominantly flat electron-poor aromatics in water, binds them mainly by pi-cation, pi-pi, CH-pi, and hydrophobic interactions, and leads to their highly efficient desolvation. NAD(+) and NADP, the important cofactors of many redox enzymes, are recognized by the new receptor molecule, which embraces the catalytically active nicotinamide site and the adenine unit. Even nucleosides such as adenosine are likewise drawn into the clip's cavity. Complex formation and structures were examined by one- and two-dimensional NMR spectroscopy, Job plot analyses, and isothermal titration microcalorimetric (ITC) measurements, as well as quantum chemical calculations of (1)H NMR shifts. The new receptor molecule is a promising tool for controlling enzymatic oxidation processes and for DNA chemistry.