Development of Antibacterial and Antifungal Triazole Chromium(III) and Cobalt(II) Complexes: Synthesis and Biological Activity Evaluations

Abstract

In this work, six complexes (2–7) of Cr(III) and Co(II) transition metals with triazole ligands were synthesized and characterized. In addition, a new ligand, 3,5-bis(1,2,4-triazol-1-ylmethyl)toluene (1), was synthesized and full characterized. The complexes were obtained as air-stable solids and characterized by melting point, electrical conductivity, thermogravimetric analysis, and Raman, infrared and ultraviolet/visible spectroscopy. The analyses and spectral data showed that complexes 3–7 had 1:1 (M:L) stoichiometries and octahedral geometries, while 2 had a 1:2 (M:L) ratio, which was supported by DFT calculations. The complexes and their respective ligands were evaluated against bacterial and fungal strains with clinical relevance. All the complexes showed higher antibacterial and antifungal activities than the free ligands. The complexes were more active against fungi than against bacteria. The activities of the chromium complexes against Candida tropicalis are of great interest, as they showed minimum inhibitory concentration 50 (MIC50) values between 7.8 and 15.6 μg mL−1. Complexes 5 and 6 showed little effect on Vero cells, indicating that they are not cytotoxic. These results can provide an important platform for the design of new compounds with antibacterial and antifungal activities.

Biological Activity of New Cichoric Acid–Metal Complexes in Bacterial Strains, Yeast-Like Fungi, and Human Cell Cultures In Vitro

“…The previous studies have indicated that the antimicrobial capacity of polyphenolic compounds depends on their properties and structure. As reported by Murcia et al, antibacterial and antifungal responses to treatments may due to different lipophilic properties and dipole moments of examined complexes [40]. Moreover, research conducted by Wu et al (2013) demonstrated that antimicrobial ability is associated with a negative correlation between the relative hydrophobicity and the numbers of hydroxyl groups in some polyphenolic compounds (flavonoids) [33].…”

Copper(II) and Zinc(II) Complexes of Mono- and Bis-1,2,3-Triazolesubstituted Heterocyclic Ligands

“…H-3''), 7.93 -7.82 (4H, m, H-5',9', H-5'',9''), 7.65 -7.53 (4H, m, H-6',8', H-6'',8''), 7.53 -7.42 (2H, m, H-7', H-7''), 7.22 -7.10 (2H, m, H-3,5), 7.01 -6.94 (2H, m, H-2,6), 6.65 (1H, t, J = 7.2 Hz, H-4), 4.81 (4H, s, H-1', H-1''). 13 N,N-Bis[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]aniline (9c). 56 Benzyl azide was prepared in situ: benzyl chloride (4.3 mL, 3.74 mmol) was dissolved in 6 mL of tert-butanol and 6 mL of water, followed by addition of sodium azide (182.7 mg, 2.81 mmol) and triethylamine (0.7 mL, 4.01 mmol).…”

“…[1][2][3][4][5][6] Regioselective formation of 1,4-disubstituted 1,2,3triazole-based mono-, bi-or multidentate chelating ligands has received considerable attention because of its broad application in drug development, optics, redox sensing, fluorescence and catalysis. 2,3,[7][8][9][10][11][12][13] The large dipole moment of triazoles, around 5 D, allows easy formation of hydrogen bonds, as well as dipoledipole and π-interactions, which can favour their binding to biological targets and improve their solubility. 14 Moreover, 1,2,3triazoles are found to be versatile ligands that can coordinate to metals through the N3, N2 and C5 donor sites, with preferential coordination at the N3 atom.…”

Synthesis, Characterization and Antibacterial Studies of (3,3-Dimethyl-7-oxo-6-(2-phenylacetamido)-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid-Cr (III) Complex

“…The results from the antimicrobial screening tests reported an improvement in the antibacterial activity of the new chromium (III) complexes against Pseudomonas aeruginosa and Methicillin Resistant Staphylococcus aureus (MRSA) species compared to ampicillin [10]. Six complexes of Cr(III) metals with triazole ligands were synthesized [11]. All the complexes showed higher antibacterial activities than the free ligands [11].…”

“…Six complexes of Cr(III) metals with triazole ligands were synthesized [11]. All the complexes showed higher antibacterial activities than the free ligands [11]. Arising from the fact that Cr complexes have shown significant performance against the microbial activity, it becomes interesting to note that to the best of our knowledge, benzylpenicillin-Cr complex and its antibacterial studies have not been reported elsewhere.…”