Quaternary ammonium surfactant structure determines selective toxicity towards bacteria: mechanisms of action and clinical implications in antibacterial prophylaxis was written by Inacio, Angela S.;Domingues, Neuza S.;Nunes, Alexandra;Martins, Patricia T.;Moreno, Maria J.;Estronca, Luis M.;Fernandes, Rui;Moreno, Antonio J. M.;Borrego, Maria J.;Gomes, Joao P.;Vaz, Winchil L. C.;Vieira, Otilia V.. And the article was included in Journal of Antimicrobial Chemotherapy in 2016.Electric Literature of C17H30BrN This article mentions the following:
Broad-spectrum antimicrobial activity of quaternary ammonium surfactants (QAS) makes them attractive and cheap topical prophylactic options for sexually transmitted infections and perinatal vertically transmitted urogenital infections. Although attributed to their high affinity for biol. membranes, the mechanisms behind QAS microbicidal activity are not fully understood. The authors evaluated how QAS structure affects antimicrobial activity and whether this can be exploited for use in prophylaxis of bacterial infections. Acute toxicity of QAS to in vitro models of human epithelial cells and bacteria were compared to identify selective and potent bactericidal agents. Bacterial cell viability, membrane integrity, cell cycle and metabolism were evaluated to establish the mechanisms involved in selective toxicity of QAS. QAS toxicity normalized relative to surfactant critical micelle concentration showed n-dodecylpyridinium bromide (C12PB) to be the most effective, with a therapeutic index of ∼10 for an MDR strain of Escherichia coli and >20 for Neisseria gonorrhoeae after 1 h of exposure. Three modes of QAS antibacterial action were identified: impairment of bacterial energetics and cell division at low concentrations; membrane permeabilization and electron transport inhibition at intermediate doses; and disruption of bacterial membranes and cell lysis at concentrations close to the critical micelle concentration In contrast, toxicity to mammalian cells occurs at higher concentrations and, as the authors previously reported, results primarily from mitochondrial dysfunction and apoptotic cell death. Thus, short chain (C12) n-alkyl pyridinium bromides have a sufficiently large therapeutic window to be good microbicide candidates. In the experiment, the researchers used many compounds, for example, 1-Dodecylpyridin-1-ium bromide (cas: 104-73-4Electric Literature of C17H30BrN).
1-Dodecylpyridin-1-ium bromide (cas: 104-73-4) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). Reduced pyridines, namely tetrahydropyridines, dihydropyridines and piperidines, are found in numerous natural and synthetic compounds. The synthesis and reactivity of these compounds have often been driven by the fact many of these compounds have interesting and unique pharmacological properties. Electric Literature of C17H30BrN