Antimicrobial activity of quaternary ammonium compounds

The antimicrobial properties of two new imidazolium and pyridinium chlorides in comparison with three currently in disinfection compounds applied are described. The following research was performed: resistance of organisms to disinfectants and disinfection of hands. The new 3-methyl-n-dodecylthiomethylpyridinium chlorid was the most active compound.     

Virucidal activity of some quaternary ammonium compounds.

Four different quaternary ammonium compounds were tested by microtechniques for evaluating their activity against the type species of six viral groups very frequently involved in human and animal pathology. Three disinfectants showed good activity against five of the representative viruses under test, while the fourth proved less effective. Poliovirus type 1 was found to be completely resistant.     

Marine lipids for prodrugs, soft compounds and other pharmaceutical applications

In the present review we discuss different approaches to pharmaceutical applications of marine lipids. Investigation of the use of marine lipids as dermal permeation enhancers, the synthesis of triacylglycerols highly enriched in polyunsaturated fatty acids, dermal pro-drugs derivatives of unsaturated fatty acids and diacyl glyceryl derivatives, and the possible synthesis of soft disinfectants from marine fatty acids.     

Investigation of soft long chain quaternary ammonium compounds as co-factors to enhance in vitro gene delivery

The effect of soft long chain quaternary ammonium antibacterial agents on the in vitro gene delivery of a luciferase plasmid to COS-1 cell lines was investigated. Low concentrations of these compounds could be used to enhance gene delivery with Lipofectamine Plus.     

Synthesis of novel porphyrin-based lipids and their antibacterial activity

The purpose of this study was to investigate the antibacterial activity of newly developed cationic amphiphilic lipids having porphyrin as head group against two types of gram-positive bacteria and three types of gram-negative bacteria. The antibacterial activity of quantitatively prepared porphyrin-based amphiphilic lipids is evaluated by the disc-diffusion method against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae and Proteus vulgaris. These results are compared with the standard antibacterial activity of chloramphenicol. Both lipids showed antibacterial behaviour against gram-positive and gram-negative bacteria.     

Synthesis andin vitro antibacterial activity of quaternary ammonium cephalosporin derivatives bearing oxazolidinone moiety

Several oxazolidinones having amine moiety were prepared to form a quaternary ammonium salt with cephalosporin nucleus, and antibacterial activity of the quaternary ammonium cephalosporin derivatives bearing oxazolidinone moiety were examined particularly with expectation of dual activity. However, the cephalosporin-oxazolidinone compounds revealed rather weaker antibacterial activity in vitro than their parent oxazolidinone and cephalosporin without showing any characteristic activity as expected.     

Patent Evaluation: Halopropargylated cyclic quaternary ammonium compounds as antimicrobial agents

Novelty: Novel halopropargylated cyclic quaternary ammonium compounds are disclosed which are useful as antimicrobial agents and possess activity against a broad spectrum of fungi and bacteria, as well as low toxicity and favourable environmental profiles.

Biology: The compounds were assaycd for their bacterial and fungicidal ability using MIC tests against P. aeruginosa, S. aureus, E. coli and A. niger. Results are given in four tables. The compounds show excellent activity again3 Gram-negative bacteria such as E. coli.

Chemistry: Syntheses of the compounds are described in five examples, including that of 1 -tetradecyl- 1 -(3-iodopropargyl)pyrrolidinium 4-methylbenzenesulphonate.     

Synthesis and bactericidal activity of quaternary ammonium compounds containing an asymmetric nitrogen atom

Translated from Khimiko-farmatsevticheskii Zhurnal, Vol. 24, No. 1, pp. 36–38, January, 1990.     

Identification of quaternary ammonium compounds as potent inhibitors of hERG potassium channels

The human ether-a-go-go-related gene (hERG) channel, a member of a family of voltage-gated potassium (K⁺) channels, plays a critical role in the repolarization of the cardiac action potential. The reduction of hERG channel activity as a result of adverse drug effects or genetic mutations may cause QT interval prolongation and potentially leads to acquired long QT syndrome. Thus, screening for hERG channel activity is important in drug development. Cardiotoxicity associated with the inhibition of hERG channels by environmental chemicals is also a public health concern. To assess the inhibitory effects of environmental chemicals on hERG channel function, we screened the National Toxicology Program (NTP) collection of 1408 compounds by measuring thallium influx into cells through hERG channels. Seventeen compounds with hERG channel inhibition were identified with IC₅₀ potencies ranging from 0.26 to 22 μM. Twelve of these compounds were confirmed as hERG channel blockers in an automated whole cell patch clamp experiment. In addition, we investigated the structure-activity relationship of seven compounds belonging to the quaternary ammonium compound (QAC) series on hERG channel inhibition. Among four active QAC compounds, tetra-n-octylammonium bromide was the most potent with an IC₅₀ value of 260 nM in the thallium influx assay and 80 nM in the patch clamp assay. The potency of this class of hERG channel inhibitors appears to depend on the number and length of their aliphatic side-chains surrounding the charged nitrogen. Profiling environmental compound libraries for hERG channel inhibition provides information useful in prioritizing these compounds for cardiotoxicity assessment in vivo.     

Novel Chromatographic methods for monitoring quaternary ammonium compounds in biological fluids

Three novel Chromatographic methods for the determination of quaternary ammonium compounds with biomedical applications are presented and their sensitivity, selectivity, reproducibility and applicability for different groups of the compounds are compared. The first one is a gas Chromatographie method for those compounds with three identical short-chain alkyl groups attached to the nitrogen atom and describes a reproducible dealkylation in the injection port of the gas Chromatograph to their respective tertiary amines. An alkali-flame ionisation detector is used as a sensitive and selective detector. The second one is a method for quaternary ammonium compounds with an ester function and is based on hydrolysis and derivatisation of the resulting acids with pentafluorobenzyl bromide, followed by gas chromatography with electron capture detection. The third method is based on ion-pair adsorption high performance liquid chromatography by adding an inorganic counter-ion to the mobile phase.