Unsaturated Gemini Surfactants with a Semi-Rigid Spacer: Micellization and Antimicrobial Activity
- 1Department of Bioactive Products, Faculty of Chemistry, Adam Mickiewicz University Poznan, Uniwersytetu Poznańskiego 8, 61-614 Poznan, Poland
- 2GEMSUR Sp. z o.o., Parkowa 6, Swadzim, 62-080 Tarnowo Podgorne, Poland
- 3Institute of Fermentation Technology and Microbiology, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, 90-530 Lodz, Poland
Abstract
A homologous series of but-2-ene-1,4-bis(N-alkyl-N,N-dimethylammonium bromides) containing C12, C14, C16, and C18 alkyl chains was investigated to determine the influence of hydrophobic-chain length and a semi-rigid unsaturated spacer on aggregation and antimicrobial properties. The critical micelle concentration decreased from the C12 to the C16 derivative, whereas further chain elongation to C18 resulted in an increase in CMC, indicating that micellization is governed not only by hydrophobicity but also by molecular packing effects. Negative standard Gibbs energies confirmed spontaneous micellization. Antimicrobial activity showed the opposite trend: the C12 derivative was the most active compound against all tested microorganisms, with MIC (minimum inhibitory concentration) values as low as 0.06 mM (12-4ene-12 against C. albicans). Increasing alkyl-chain length markedly reduced activity, particularly against Escherichia coli, for which the MIC increased from 0.12 mM for C12 to over 62.5 mM for C18, demonstrating a pronounced cut-off effect. Staphylococcus aureus remained more susceptible to longer-chain homologues than E. coli, while notable activity was also observed against yeast and filamentous fungi. DFT calculations further indicated that spacer unsaturation affects the electronic properties of the molecules. Overall, the results demonstrate a strong relationship between alkyl-chain length, micellization, spacer rigidity, and antimicrobial performance.
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BibTeX
@article{kowalczyk2026unsaturated,
title = {{Unsaturated Gemini Surfactants with a Semi-Rigid Spacer: Micellization and Antimicrobial Activity}},
author = {Iwona Kowalczyk and Adrianna Szulc and Justyna Brycka and Anna Komasa and Anna Koziróg and Bartosz Grabowski and Bogumił Brycki},
journal = {Molecules},
year = {2026},
month = nov,
doi = {10.3390/molecules31213969},
url = {https://www.mdpi.com/1420-3049/31/21/3969},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Unsaturated Gemini Surfactants with a Semi-Rigid Spacer: Micellization and Antimicrobial Activity
AU - Iwona Kowalczyk
AU - Adrianna Szulc
AU - Justyna Brycka
AU - Anna Komasa
AU - Anna Koziróg
AU - Bartosz Grabowski
AU - Bogumił Brycki
PY - 2026
DA - 2026/11/03
JO - Molecules
DO - 10.3390/molecules31213969
UR - https://www.mdpi.com/1420-3049/31/21/3969
AB - A homologous series of but-2-ene-1,4-bis(N-alkyl-N,N-dimethylammonium bromides) containing C12, C14, C16, and C18 alkyl chains was investigated to determine the influence of hydrophobic-chain length and a semi-rigid unsaturated spacer on aggregation and antimicrobial properties. The critical micelle concentration decreased from the C12 to the C16 derivative, whereas further chain elongation to C18 resulted in an increase in CMC, indicating that micellization is governed not only by hydrophobicity but also by molecular packing effects. Negative standard Gibbs energies confirmed spontaneous micellization. Antimicrobial activity showed the opposite trend: the C12 derivative was the most active compound against all tested microorganisms, with MIC (minimum inhibitory concentration) values as low as 0.06 mM (12-4ene-12 against C. albicans). Increasing alkyl-chain length markedly reduced activity, particularly against Escherichia coli, for which the MIC increased from 0.12 mM for C12 to over 62.5 mM for C18, demonstrating a pronounced cut-off effect. Staphylococcus aureus remained more susceptible to longer-chain homologues than E. coli, while notable activity was also observed against yeast and filamentous fungi. DFT calculations further indicated that spacer unsaturation affects the electronic properties of the molecules. Overall, the results demonstrate a strong relationship between alkyl-chain length, micellization, spacer rigidity, and antimicrobial performance.
SN - 1420-3049
ER -