Synthesis and Biological Activity of Alkyl Pyridinium Aldoxime Based Surfactants

Abstract

A series of N-alkyl pyridinium aldoxime surfactants was synthesized by the reaction of pyridinium aldoxime with long chain alkyl halides (decyl, dodecyl, tetradecyl and hexadecyl bromide). The chemical structure of the synthesized compounds was confirmed by elemental analysis and FTIR spectra. Surface tension was measured in aqueous solutions for different concentrations at 25 °C. Various surface properties of the synthesized surfactants were evaluated, particularly the critical micelle concentration (CMC), effectiveness (πCMC), efficiency (PC20) as well as the maximum surface excess (Γmax) and minimum surface area (Amin). Also, the micellization and adsorption at liquid/air interfaces were investigated. The synthesized cationic surfactants were evaluated for their biocidal activity. Good antibacterial and antifungal activities were recorded against Gram-positive bacteria (Bacillus subtilis ATCC 6633, Micrococcus luteus ATCC 25922), followed by Gram-negative bacteria (Escherichia coli ATCC 23282, Pseudomonas aeruginosa ATCC 10145), yeast (Candida albicans IMRU 3669) and filamentous fungus (Aspergillus niger ATCC 16404).

Degradation of Organophosphate Pesticides Using Pyridinium Based Functional Surfactants

“…The pyridinium based surfactants can provide a reduced half-life of the insecticide paraoxon to minutes (see Table ) in water under mild pH (below pH 10) and concentration conditions. As was recently shown for the structurally similar 2-oximinopyridinium surfactants, the microbial toxicity of the functional surfactants is not dramatically different from those having a pyridinium headgroup without a nucleophilic moiety. The “benign by design” approach reported recently by Kümmerer and Gathergood , may open an opportunity for using degradable functionalized pyridinium surfactants and ionic liquids as the base for sustainable decontamination formulations.…”