Background: The quaternary ammonium compounds (QAC) are the important group of
chemical individuals with widespread usage in many fields of industry or science. The surface-active
cationic surfactants are well known disinfection agents. Its effectivity against gram-positive, gramnegative
bacteria, yeasts and some viruses is already used in many preparations. On the other hand, the
emergence of resistance is the cause of an increasing necessity of new substances.
Methods: The series of 5-alkyl-7-hydroxy-2,3-dihydro-[1,4]dioxino[2,3-b]pyridin-5-ium bromides has
been synthesized as a novel potential antimicrobial agent. Reaction of the nucleophilic substitution
type has been used. The novel compounds have been tested as disinfection agents against bacteria and
fungi. The microdilution broth method was utilized for antimicrobial evaluation. Standard MTT test
was used for cytotoxic evaluation.
Results: We have prepared 5 new compounds based on 2,3-dihydro-[1,4]dioxino[2,3-b]pyridin-7-ol
with different length of lipophilic alkyl chain on the quaternary nitrogen (C10-18). The compounds were
characterized with analytical data (NMR, HRMS) and evaluated as wide spectrum antimicrobial agents
against pathogenic fungal and bacterial strains. We have observed the efficacy towards microbial cells
of C12 and C14 compounds for only several antimicrobial strains (Staphylococcus aureus, Candida
krusei, Candida glabrata, Trichophyton mentagrophytes).
Conclusion: We report on the preparation and characterization of a set of novel cationic surfactant-like
compounds based on 2,3-dihydro-[1,4]dioxino[2,3-b]pyridin-7-ol. The novel compounds have been
evaluated as wide spectrum antimicrobial agents against pathogenic fungal and bacterial strains. Only
two compounds with alkyl chain C12 and C14 showed significant activity against microbes. So, these
two compounds should be considered as the potential disinfectants with the selective effect against certain
bacterial and fungal strains, not as wide spectra antimicrobial agents.