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PubMed1977

Bactericidal properties of quaternary ammonium compounds in dispersed systems.

Alkyltrimethylammonium bromides of selected chain length were synthesized and characterized with respect to their bactericidal properties. A partitioning method was developed, and the aqueous phases of the partitioned systems were evaluated for their antibacterial activity against Staphylococcus aureus. The relationships between the quaternary ammonium compound chain length and the aliphatic alcohol chain length were determined. The effect of selected hydrocarbons on the bactericidal effectiveness of the systems was studied. Cream systems corresponding to the partitioned systems were prepared and evaluated against S. aureus. The relationship between the aqueous phase concentration of the bactericidal agent was studied, and a correlation was shown between the bactericidal activity of the partitioned systems and cream systems.

Anti-Infective Agents, Local↗
PubMedDate not supplied

Microsomal glucuronidation of a quaternary ammonium compound, 3-hydroxyphenyltrimethylammonium.

3-Hydroxyphenyltrimethylammonium (HPTMA) is glucuronidated in vitro by rat liver microsomes supplemented with UDP-glucuronic acid. Little reaction occurred in the postmicrosomal supernatant fraction. Triton X-100 doubled the maximal velocity for the microsomecatalyzed reaction without altering the apparent KM value for HPTMA. This is the first report of glucuronidation of a quaternary ammonium compound in vitro.

Animals↗
PubMed1988

Effects of some mono- and bisquaternary ammonium compounds on the reactivatability of soman-inhibited human acetylcholinesterase in vitro.

Acetylcholinesterase (AChE) inhibited by the organophosphate soman (1,2,2-trimethyl-propylmethylphosphonofluoridate) rapidly becomes resistant to reactivation by oximes due to dealkylation of the soman-enzyme complex. This reaction is called aging. The effect of the four mono- and bisquaternary ammonium compounds tetramethylammonium (TMA), hexamethonium, decamethonium and suxamethonium on the reactivatability of soman-inhibited, solubilized AChE from human erythrocytes was investigated in vitro. All compounds were reversible inhibitors of AChE; the respective dissociation constants and the type of inhibition exhibited considerable differences. The affinities to both the active and the allosteric site were considerably higher for suxamethonium (Kii 81.3 microM; Ki 15.9 microM) and decamethonium (Kii 15.4 microM; Ki 4.4 microM) than for TMA (Kii 1 mM; Ki 289.6 microM) and hexamethonium (Kii 4.5 mM; Ki 331.8 microM). The reactivation experiments were performed in a four-step procedure (soman-inhibition at 0 degree and pH 10, aging at 37 degrees and pH 7.3, reactivation by the oxime HI 6 at 37 degrees and pH 7.3 followed by AChE assay). After these four steps (total duration 55 min), AChE was inhibited by soman to 95-100%. HI 6 could reactivate about 20% of the inhibited enzyme. All effectors increased the AChE reactivatability by HI 6 when added before aging was started. The maximal increase in reactivatability was higher in the presence of 1.6 mM suxamethonium (+35.8%) and 150 microM decamethonium (+40%) than of 22 mM TMA (+22.5%) and 8.3 mM hexamethonium (+19.2%). If the effectors were added after 5 min of aging they increased the activity of soman-inhibited AChE, but to a considerably smaller extent than HI 6. A good correlation of the respective Kii values and the effective concentrations of these drugs was observed, indicating that an allosteric binding site of AChE might be involved in the protective effect of these drugs.

Acetylcholinesterase↗
PubMed1990

[Identification of bis-quaternary ammonium compounds using mild ionization mass spectrometry].

Ethonium, an antimicrobial chemotherapeutic agent, was investigated by mass spectrometry (MS) under various ionization conditions: electron impact, field ionization, field desorption (FD) and fast atom ionization. FDMS was found to be the most suitable procedure for ethonium identification. Relation of the ED mass spectra to the distance between the nitrogen atoms in bis-quaternary ammonium compounds is discussed. It was shown that the most intensive ions with m/z 499, 315 in the FD mass spectra corresponded to the ethonium specific fragmentation and their occurrence in the spectra could serve as a sufficient criterion useful in qualitative and quantitative assay of the drug in the sample.

Chemical Phenomena↗
PubMedDate not supplied

Human studies on the bioavailability of a quaternary ammonium compounds, tiemonium iodide and tiemonium methosulphate.

Five volunteers were administered capsules containing 14C-labelled tiemonium iodide and 4 volunteers received capsules of 14C-labelled tiemonium methosulphate. Serum, urine and faecal levels of tiemonium were measured. The percentage of the dose absorbed was determined after a further labelled intravenous injection into 3 of the volunteers. The drug appeared to be poorly absorved, as expected for quaternary ammonium compounds, but there was no difference in the bioavailability of these two tiemonium salts.

Administration, Oral↗
PubMed2003

The role of analogue ions in the ion-pair reversed-phase chromatography of quaternary ammonium compounds.

The choice of analogue ion of the mobile phase additive is shown to significantly affect the analysis of quaternary ammonium compounds (QACs) in ion-pair reversed-phase high-performance liquid chromatography. A series of bromide-containing and dodecyl-sulfate-containing mobile phase additives are investigated using two QAC probe analytes. In all instances, the quaternary-ammonium-containing mobile phase additives perform better than the corresponding sodium-containing additives for effective QAC elution. These results indicate that the structure of the analogue ion, not just its formal charge, is important in the reversed-phase ion-pair chromatography of these compounds. The relative elution order of the QAC probe analytes is also influenced by the counter ions of the mobile phase additives, with bromide and dodecyl sulfate offering opposite elution orders.

Journal Article↗
PubMed2005

Significance of ammonium compounds on nicotine exposure to cigarette smokers.

The tobacco industry publicly contends that ammonia compounds are solely used as tobacco additive for purposes of tobacco flavoring, process conditioning and reduction of its subjective harshness and irritation. However, neither objective scientific reports, nor the contents of a large number of internal tobacco company documents support this contention. The present review focuses on the hypothesis that addition of ammonium compounds to tobacco enhances global tobacco use due to smoke alkalization and enhanced free-nicotine nicotine exposure. Obviously, ammonia enhances the alkalinity of tobacco smoke. Consequently, the equilibrium shifts from non-volatile nicotine salts to the volatile free base that is more readily absorbed from the airways. The observed change in the kinetics of nicotine (i.e., shorter t(1/2) and higher c(max)) after ammoniation is, however, predominantly due to the higher concentration of nicotine in the smoke, rather than to an increase in the absorption rate of free-base nicotine in the respiratory tract. Although several findings support the hypothesis, additional studies are required and suggested to provide a proper, objective and independent scientific judgment about the effect of tobacco ammoniation on nicotine bioavailability. Scientific and public awareness of the effects of tobacco-specific ammonia compounds may stimulate global control, legislation and restriction of their use in cigarette manufacture.

Absorption↗
PubMed1993

Biological inactivation of adhering Listeria monocytogenes by listeriaphages and a quaternary ammonium compound.

The use of listeriaphages as a means of disinfecting contaminated stainless-steel and polypropylene surfaces was investigated. Surfaces artificially contaminated with L. monocytogenes 10401 and 8427 were sanitized with suspensions of listeriaphages (H387, H387-A, and 2671), all belonging to the Siphoviridae family. Phage suspensions at concentrations of up to 3.5 x 10(8) PFU/ml were at least as efficient as a 20 ppm solution of a quaternary ammonium compound (QUATAL) in reducing L. monocytogenes populations. A synergistic activity was observed when two or more phages were used in combination and when phages were suspended in QUATAL. The biological activity of the three phages was not affected by QUATAL concentrations of 50 ppm and a contact time of 4 h.

Bacterial Adhesion↗