Volume: 5, 2026
5th International PhD Students’ Conference at the University of Life Sciences in Lublin, Poland:
ENVIRONMENT – PLANT – ANIMAL – PRODUCT
Abstract number: H019
DOI: https://doi.org/10.24326/ICDSUPL5.H019
Published online: 22 April 2026
Searching for novel antifungal compounds forming synergistic systems with polyene and azole antibiotics
Lidia Ślusarczyk*1, Aleksandra Hnydka2, Dariusz Karcz3, Arkadiusz Matwijczuk1 and Katarzyna Klimek2
1 Department of Biophysics, Faculty of Environmental Biology, University of Life Sciences in Lublin, 13 Akademicka St., 20-950, Lublin, Poland
2 Chair and Department of Biochemistry and Biotechnology, Medical University of Lublin,1 Chodzki St., 20-093 Lublin, Poland
3 Department of Chemical Technology and Environmental Analytics, Krakow University of Technology, 24 Warszawska St., 31-155 Krakow, Poland
* Corresponding author: lidia.slusarczyk@up.lublin.pl
Compounds from the 1,3,4-thiadiazole group and their derivatives constitute an extremely promising class of heterocyclic compounds. They are characterized by a broad spectrum of biological activity, including antifungal, antibacterial, and anticancer effects. In recent years, scientists around the world have focused on finding new active substances with antifungal activity, due to increasing microbial resistance. Our research also indicates the possibility of synergistic effects between 1,3,4-thiadiazole derivatives and conventional antifungal drugs, which may lead to increased treatment efficacy while simultaneously reducing effective therapeutic doses. The aim of this study was to evaluate the antifungal activity of a selected derivative from the 1,3,4-thiadiazole group: (E)-5-(diethylamino)-2- (((5-(4-methoxyphenyl)-1,3,4-thiadiazol-2-yl)imino)methyl)phenol, compared with conventional antifungal drugs such as amphotericin B, flucytosine, and natamycin. Standard microbiological methods were used to determine the minimum inhibitory concentration (MIC) and the fractional inhibitor concentration index (FICI). Cytotoxicity analysis was also performed to determine the safety of the tested systems. This compound demonstrated a favorable safety profile – the MIC to CC50 ratio exceeded 2, indicating relatively low toxicity with preserved biological activity. This compound also demonstrated a beneficial synergistic effect with the antibiotic amphotericin B against both tested strains: Candida parapsilosis and Candida albicans. With natamycin, the compound demonstrated synergism against the C. parapsilosis strain. With flucytosine, however, it demonstrated additive activity against C. albicans, but showed a neutral effect against C. parapsilosis. These studies were also supplemented with spectroscopic measurements to analyze the molecular mechanism of this synergism. For this purpose, absorption, fluorescence emission, and resonance light scattering (RLS) measurements were performed in buffer systems.
These studies confirmed the interaction between the tested compound and selected antifungal drugs. The obtained results indicate that 1,3,4-thiadiazole derivatives, and particularly the TD-MP-DEA compound, may constitute an interesting group of compounds that form effective antifungal synergistic systems with antibiotics such as amphoreticin B, flucytosine, and natamycin. They also emphasize the need for further research into the mechanism of action of this synergism.
Keywords: 1,3,4-thiadiazoles; antifungal acticity; synergistic effect
How to cite
Ślusarczyk L., Hnydka A., Karcz D., Matwijczuk A., Klimek K., 2026. Searching for novel antifungal compounds forming synergistic systems with polyene and azole antibiotics. In: 5th International PhD Students’ Conference at the University of Life Sciences in Lublin, Poland: Environment – Plant – Animal – Product. https://doi.org/10.24326/ICDSUPL5.H019