Abstract
Recently, we synthesized silver(I) complex with the antifungal agent itraconazole, which showed improved anti-Candida potential and therapeutic safety in comparison to itraconazole and rescued zebrafish embryos affected by lethal C. albicans infection, when used in safe doses. Inspired by these results, in the present study, three new silver(I) complexes with clinically used azoles, econazole (ecz), clotrimazole (ctz) and voriconazole (vcz), [Ag(ecz)2]SbF6 (Ag1), [Ag(ctz)2]SbF6 (Ag2) and {[Ag(vcz)2]SbF6}n (Ag3) were synthesized and structurally characterized by elemental microanalysis, mass spectrometry, spectroscopy (1H NMR, IR and UV-Vis), cyclic voltammetry, molar conductivity measurements, and single crystal X-ray diffraction analysis. The spectroscopic and crystallographic results revealed that, in the synthesized silver(I) complexes, azole ligands are monodentately coordinated to the Ag(I) ion through the nitrogen atom forming [Ag(azole)2]+ complex cation. The antimicrobial effect of complexes and azole ligands was evaluated against different Candida species, as well as Gram-positive and Gram-negative bacteria. The synthesized complexes Ag1-3 exhibited good to moderate antimicrobial activity being, in most cases, more active than the corresponding azole ligands. Complexes Ag2 and Ag3 also showed strong inhibitory activity against C. albicans biofilm formation and strong inhibition of C. albicans filamentation at subinhibitory concentrations.
Supplementary Materials
The following are available online at https://www.mdpi.com/article/10.3390/ECMC2022-13249/s1.
Author Contributions
Conceptualization, N.L.S., I.T., M.I.D. and B.Đ.G.; methodology, N.L.S., J.N.-R., I.T., M.I.D. and B.Đ.G.; software, J.K.; validation, J.N.-R., I.T., M.I.D. and B.Đ.G.; investigation, N.L.S., J.L., J.K. and M.S.; resources, J.N.-R., I.T., M.I.D. and B.Đ.G.; writing—original draft preparation, N.L.S., J.L., J.K. and M.S.; writing—review and editing, J.N.-R., I.T., M.I.D. and B.Đ.G.; visualization, N.L.S., J.L., J.K. and M.S., funding acquisition, J.N.-R., I.T., M.I.D. and B.Đ.G. All authors have read and agreed to the published version of the manuscript.
Funding
This research has been financially supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia (Agreements No. 451-03-68/2022-14/200042 and 451-03-68/2022-14/200122) and by the Slovenian Research Agency (grant P1-0175). The EN→FIST Centre of Excellence, Trg OF 13, SI-1000 Ljubljana, Slovenia, is acknowledged for the use of the SuperNova diffractometer. This research has also received funding from the Serbian Academy of Sciences and Arts under project No. F128.
Institutional Review Board Statement
Not applicable.
Informed Consent Statement
Not applicable.
Data Availability Statement
The spectroscopic data used to support the findings of this study are available on request from the corresponding author.
Conflicts of Interest
The authors declare no conflict of interest.
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