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PubMed1988

Relationships between chemical structure and inhibition of choline acetyltransferase by 2-(alpha-naphthoyl)ethyltrimethylammonium and related compounds.

A choline acetyltransferase (ChA) inhibitor with an optimum combination of properties of potency, stability and membrane permeability is required to study several functional aspects of acetylcholine in nervous and non-nervous tissues. Therefore, 2-(alpha-naphthoyl)ethyltrimethylammonium iodide (alpha-NETA), 2-(beta-naphthoyl)ethyltrimethylammonium iodide (beta-NETA), 2-(9'-anthroyl)ethyltrimethylammonium iodide (9'-AETA) and their corresponding tertiary dimethylamine hydrochloride analogs (alpha-NEDA, beta-NEDA, 9'-AEDA) were synthesized and tested for their ChA inhibitory activities. The quaternary ammonium compounds were more potent inhibitors (150 in microM: alpha-NETA, 9; beta-NETA, 76; 9'-AETA, 32) than the corresponding tertiary compounds (150 in microM: alpha-NEDA, 63; beta-NEDA, 1400; 9'-AEDA, 77). The alpha-naphthyl moiety was preferable to the beta-naphthyl- or 9'-anthryl moieties for alignment with the enzyme for inhibition. alpha-NETA and alpha-NEDA exhibited adequate ChA inhibitory potencies for further pharmacological studies and localization of membrane bound ChA. They exhibited fluorescent characteristics of the alpha-naphthyl moiety. Their ChA inhibition was not reversible by dialysis. They were considerably more potent for inhibiting ChA than cholinesterases and carnitine acetyltransferase.

Acetylcholine↗
PubMed1979

Growth, survival, and resistance of the Legionnaires' disease bacterium.

The Legionnaires' disease (LD) bacterium can now be readily cultured on artificial media. Studies were done to define the growth and survival of the LD bacterium in these media and ascertain its susceptibility to disinfecting agents. Growth-curve studies of the Philadelphia 1 strain using Mueller-Hinton broth with ferric pyrophosphate and L-cysteine (Feeley-Gorman broth) showed a lag phase of less than 24 h, a generation time of 3.8 h during the logarithmic phase, a plateau of 2 x 10(7) organisms per millilitre, and continued viability for as long as 110 d. Viability on chocolate agar with 1% hemoglobin and 2% IsoVitaleX added reached 150 d. This strain was susceptible to a variety of commonly recommended hospital and laboratory disinfectants, often in low concentrations. These investigations suggest that prolonged survival may occur in natural as well as artificial milieus and that low concentrations of phenolics, quaternary ammonium compounds, glutaraldehyde, formaldehyde, and hypochlorite could eradicate potential reservoirs for human infection.

Bacteria↗
PubMed1983

Neutralization of the activity of eight disinfectants by organic matter.

The effect of organic matter on the activity of eight disinfectants was evaluated. Three types of interfering substrates (whole milk powder, dried beef blood and fish meal) were tested according to the method of Whitmore and Miner adapted to the AOAC use-dilution method. Glutaraldehyde and to a certain extent, chlorhexidine acetate and the amphoteric surfactant kept their disinfecting activity after contact with high concentrations of organic matter. The quaternary ammonium compound as well as the quaternary ammonium-glutaraldehyde complex were more readily neutralized whereas anionic acid, iodophor and sodium hypochlorite did not tolerate the presence of organic matter. The neutralizing activity of powders was correlated to their solubility and composition.

Animals↗
PubMedDate not supplied

[Effect of adamantyl quaternary ammonium derivatives on the autonomic ganglia].

The ganglionic blocking activity of mono- and bis-quaternary ammonium compounds with adamantyl radicals was studied on unanesthetized mice my measuring the pupil diameter with a binocular lens. To measure the mydriatic action of the agents, experiments were performed on anesthetized cats with recording of nictiating membrane contractions under the stimulation of the cervical sympathetic trunk. It was established that the ganglionic blocking activity of mono-quaternary compounds depends on the position of the adamantyl radical in the molecule. The maximal ganglionic blocking activity was formed in ethyl-n-toluenesulphonate of beta-diethylaminoethyl ether of I-adamantyl acetic acid and in N-adamantyl analogue of tetramethylammonium. Introduction of the adamantyl radical into the cation centres of symmetrical polymethylene bis-trimethylammonium compounds (with the length of interinonic chain of 5-10 carbon atoms) leads to the loss of the ganglionic blocking activity.

Adamantane↗
PubMed1976

Iodo-bis(quaternary ammonium) salts. Potential cartilage-selective x-ray contrast agents.

Bis(quaternary ammonium) compounds in which one or both quaternary nitrogens bear iodinated benzyl moieties and the charged centers are separated by 2, 4, 6, or 10 methylene units have been synthesized and evaluted for (a) binding to cartilaginous material, (b) radiocontrast characteristics, and (c) in vitro pharmacological effects. Also prepared was 1,5-diiodo-2,4-bis(beta-trimethylammonioethyl)benzene diiodide, an analogue in which the iodinated aryl group lies between the charged nitrogen centers. Biological studies show that these compounds bind to cartilage but at relatively slow rates and with low persistence, resulting in low and transient levels of radiopacity. In common with simpler bisquaternary compounds, these compounds block synaptic transmission.

Animals↗
PubMed1996

Luminal transport system for choline+ in relation to the other organic cation transport systems in the rat proximal tubule. Kinetics, specificity: alkyl/arylamines, alkylamines with OH, O, SH, NH2, ROCO, RSCO and H2PO4-groups, methylaminostyryl, rhodamine, acridine, phenanthrene and cyanine compounds.

The efflux of [3H] choline+ from the proximal tubular lumen was measured by using the stop-flow microperfusion method. The 2-s efflux of [3H] choline+ follows kinetics with a Michaelis constant, Km = 0.18 mmol x l-1, maximal flux, Jmax = 0.43 pmol x cm-1 x s-1 and a permeability term = 38.0 micron2 small middle dots-1. Replacement of Na+ by N-methyl-D-glucamine+ or Li+, or a change of luminal pH do not alter choline+ efflux. Replacement of Na+ by Cs+ inhibits 2-s choline+ (0. 01 mmol x l-1) efflux by 22% and replacement by K+ inhibits by 49%, indicating that the electrical potential difference across the brush border membrane acts as driving force for choline+ transport. Comparing the apparent luminal inhibitory constant values for choline (app. Ki,l,choline+) with the chemical structure of inhibiting substrates, it was found that the inhibitory potency of amines with high pKa values, i.e. high basicity, and of quaternary ammonium compounds (tetraethyl to tetrahexylammonium) increases with their hydrophobicity in a similar manner as was observed previously against the contraluminal N1-methylnicotinamide (NMeN+) transporter and the luminal H+/organic cation (N-methyl-4-phenylpyridinium) (MPP+) exchanger. Independently of their hydrophobicity, an increase in the inhibitory potency of the homologous series of aminoquinolines against the choline+ transporter was observed with increasing pKa values, i.e. increasing basicity, as was found previously against the two other organic cation transporters. A third parameter influencing the interaction with the choline+ transporter is the presence of two amino groups with high pKa values or one amino group and a permanent positive charge, as is documented with the two-ring aminostyryl and rhodamine compounds, as well as three-ring aminoacridine, aminophenanthrene and cyanine compounds. Thus with the aminostyryl, pyridinium+, rhodamine, phenanthridium+ and cyanine+ dyes app.Ki,l,choline+ values of between 0.01 and 0.07 mmol x l-1 have been found. A fourth parameter influencing the choline+ transporter is the presence of an OH group on the C atom next to that bearing the N atom (as in choline+) or an ester-OCOR group (acetylcholine+, butyrylcholine+) or a thioester-SCOR-group (acetylthiocholine+, butyrylthiocholine+); or an -OP(OH)2(OR) group (glycerylphosphoryl-choline+), resulting in app.Ki,l,choline+ values of 0.3-1.0 mmol x l-1. Thus the substrates for the luminal choline+ transporter have general features in common with the luminal H+/organic cation exchanger and the contraluminal organic cation transporter, i.e. hydrophobicity and basicity. Additional parameters for interaction are an OH (or similar) group positioned a favourable distance from the N atom or a second amino/ammonium group in multi-ring compounds.

Amines↗
PubMed1980

Chemical inhibition of plaque.

Attempts to control plaque by chemical means using enzymes, antibiotics and antiseptics are reviewed. Enzymes such as mucinase, dehydrated pancreas, enzymes of fungal origin, dextranase and mutanase showed limited clinical success despite promising in vitro and animal studies. Side effects from the use of enzymes were observed. Many antibiotics have been used in attempts to control plaque and several have been successful. However, problems exist from the long-term use of such drugs which precludes their routine use as agents for controlling plaque. The biguanide chlorhexidine is the most widely used and investigated method of chemical plaque control. Many studies have been demonstrated that it will successfully control plaque. No toxic side effects have been reported from its long-term use but local side effects such as staining of the teeth do occur. The quaternary ammonium compounds have at present no advantages over the biguanides and require more frequent usage to achieve the same degree of plaque control as chlorhexidine.

Anti-Bacterial Agents↗
PubMed2000

In vivo microdialysis and reverse phase ion pair liquid chromatography/tandem mass spectrometry for the determination and identification of acetylcholine and related compounds in rat brain.

A method using liquid chromatography/tandem mass spectrometry (LC/MS/MS) has been developed for the determination of basal acetylcholine (ACh) in microdialysate from the striatum of freely moving rats. A microdialysis probe was surgically implanted into the striatum of the rats and Ringer's solution was used as the perfusion medium at a flow rate of 2 microL per minute. The samples were then analyzed off-line by LC/MS/MS experiments. The separation of ACh and choline (Ch) was carried out using reverse phase ion pair liquid chromatography with heptafluorobutyric acid as a volatile ion pairing reagent. Analytes were detected by electrospray ionization tandem mass spectrometry in the positive ion mode. The detection limit for ACh was 1.4 fmol on column, which is at least three times lower than previously reported. Three quaternary ammonium compounds in the rat brain microdialysate were also identified by tandem mass spectrometry experiments in which the unknown mass spectra were compared with standard reference compounds. These compounds were identified as carnitine, acetylcarnitine and (3-carboxypropyl)trimethylammonium. This is the first known report of the compound (3-carboxypropyl)trimethylammonium being found in rat brain.

Acetylcholine↗
PubMed1993

Non specific interactions in anti-agent IgE-RIA to anesthetic agents.

The sensitivity of usual IgE-RIA for detecting seric anti-neuromuscular blocking drug (NMBD) IgE antibodies is low. Our group and other authors have proposed quaternary ammonium compounds other than NMBD for the preparation of sepharose solid drug phase. These compounds cannot be cyclohexenyl derivatives in order to prevent hydrophobic interactions with seric hydrophobic IgE. Allergic reactions against cyclohexenyl derivatives such as propofol could be linked to a non-specific hydrophobic binding of the drug to hydrophobic seric IgE. Such hydrophobic IgE are seen in 30% of atopic subjects, in 41% of patients with drug allergy and in 100% of those allergic to propofol. The latter had also anti-quaternary ammonium IgE in 5 out of the 8 cases studied. These NMBD antibodies could bind to the quaternary-ammonium ion of the lecithins from Diprivan micelles.

Antibodies, Anti-Idiotypic↗
PubMed2006

Resistance to a polyquaternium-1 lens care solution and isoelectric points of Pseudomonas aeruginosa strains.

OBJECTIVES: The aim of this study was to correlate the cell surface hydrophobicity and charge of various strains of Pseudomonas aeruginosa with their resistance to a polyquaternium-1 lens care solution. METHODS: The 11 P. aeruginosa strains included were isolated from eyes, contact lenses, lens cases and lens care solutions. Cell surface hydrophobicities were determined from water contact angle measurements and surface charges were measured as a function of pH using particulate micro-electrophoresis. RESULTS: Strains resistant to polyquaternium-1 had an isoelectric point (IEP; pH where the bacterial zeta potential is zero) ranging from 4.0 to 5.5, whereas susceptible strains were more negatively charged than resistant strains and had an IEP between 1.3 and 1.9. Water contact angles ranged from hydrophilic (34 degrees) to hydrophobic (124 degrees), without showing a relation with antimicrobial resistance. CONCLUSIONS: Results suggest that electrostatic repulsion between cationic molecules on the cell surface and quaternary ammonium compounds impedes the antimicrobial entering the cell.

Contact Lens Solutions↗
PubMed1988

Review of the environmental toxicity of quaternary ammonium halides.

This paper summarizes all available information on the environmental toxicity of quaternary ammonium compounds (QACs). Ten-minute contact kills of bacteria occur at 50-333 mg/liter. These chemicals are acutely toxic at approximately 1 mg/liter to invertebrates and fish and toxicity is occasionally as low as 0.1 mg/liter; no-effect levels are generally 10 times lower than LC50 values. Toxicity to invertebrates and fish appears to be relatively independent of structure; the compounds studied, which have a large variety of structures, are all toxic at approximately the same order of magnitude. The QACs tested inhibited plant growth at 3-5 mg/liter. Predictions of toxicity to QACs are made based on knowledge of structure-activity relationships.

Animals↗
PubMed2001

Reversible encapsulation by self-assembling resorcinarene subunits.

Encapsulation complexes are assemblies in which a reversibly formed host more or less completely surrounds guest molecules. Host structures held together by hydrogen bonds have lifetimes in organic solvents of milliseconds to hours, long enough to directly observe the encapsulated guest by NMR spectroscopy. We describe here the action of alkyl ammonium compounds as guests that gather up to six molecules of the host module to form encapsulation complexes. The stoichiometry of the complexes--the largest hydrogen-bonded host capsules to date--is determined by the size and concentration of the guest.

Hydrogen↗
PubMed1975

Chemical structure and pharmacological (curarizing) properties of various indole alkaloids extracted from an African Strychnos.

The chemical separation and identification of ten alkaloids extracted from the roots of Strychnos usambarensis are described. The elucidation of their structure by means of elementary analysis, I. R., U.V, and mass spectrometry allows their classification into bistertiary amines, hybrid and bisquaternary ammonium derivatives. This classification is reflected in the pharmacological properties. One of the tertiary amine alkaloids (usambarensine) presents atopine-like and spasmolytic activities while the bisquaternary ammonium compounds (dihydrotoxiferine, calebassine, C-curarine and afrocurarine) are competitive neuromuscular blocking agents.

Alkaloids↗
PubMed1989

[Antiaggregatory and anticoagulant effects of oligoamines. 10. Tertiary oligoamines and quaternary ammonium salts].

Twelve tertiary oligoamines, two quaternary oligoammonium salts, two oligoamides, one oligosulfonamide, and one trinitrosamine were tested for antiplatelet and anticoagulant effects. Seven amines and one ammonium compound inhibited platelet aggregation at IC50 below 100 mumols/L. The results suggest that the formation of hydrogen bonds to phospholipids strengthens the antiplatelet activity. The sterical limits of the structural variability concerning the antiaggregatory effects are shown.

Amines↗
PubMed1987

A highly sensitive HPLC method for the assay of propantheline used to measure its uptake by rat intestinal brush border membrane vesicles.

A simple, sensitive, high-performance liquid chromatographic method for propantheline has been developed. Propantheline was quantitatively hydrolysed into xanthene-9-carboxylic acid in neutral or alkaline medium and the hydrolysate assayed by reversed phase high-performance liquid chromatography. This method measured to 2 pmol per injection and was used to investigate the uptake of the drug by rat intestinal brush border membrane vesicles. Propantheline was highly bound to the membrane and this binding was inhibited to varying extents by several quaternary ammonium compounds. Mepenzolate and methylbenactyzium inhibited it significantly, and neostigmine, butylscopolamine and N-methylnicotinamide inhibited it moderately. Choline, acetylcholine and thiamine had no effect.

Animals↗
PubMedDate not supplied

[Radioprotective activity, toxicity and mechanism of action of bis-(beta-dimethyl octyl ammonium ethyl)disulfide].

Disulfide bis-(beta-dimethyl octyl ammonium ethyl) and some of its analogues were shown to have a radioprotective effect. It is suggested that the mechanism of radioprotective action of quaternary ammonium compounds involves both a temporary inhibition of DNA synthesis in radiosensitive tissues and inhibition of oxidative processes in the organism.

Acid-Base Equilibrium↗
PubMed1992

Racemization and intramolecular nucleophilic substitution reactions of ibutilide.

The kinetics and mechanisms of the racemization and cyclization reactions of ibutilide are described. The cyclization reaction yields a bell-shaped rate-pH curve consistent with a change in rate-determining step. It is hypothesized that the hydroxyl group leaves to form a carbocation intermediate; this is followed by nucleophilic attack by the amine. This mechanism is supported by kinetic analysis, aniline trapping of carbocation intermediate, and observation of all four stereo-isomers of the resulting quaternary ammonium compound. Whereas racemization can also progress through the carbocation intermediate, a direct SN2 mechanism appears to be the major route for the racemization reaction.

Anti-Arrhythmia Agents↗