Polymeric zinc complexes with 2,2′-dipyridylamine and different benzenepolycarboxylato ligands: Synthesis, structure, characterization and antimicrobial activity

New copper(II) cyclam complexes with aminocarboxylate co-ligands: Synthesis, characterization, and in vitro antiproliferative and antibacterial studies

Two new cationic Cu(II) complexes of cyclam (1,4,8,11-tetraazacyclo-tetradecane) and aminocarboxylate coligands glycine or alanine have been synthesized. The complexes were characterized by elemental analysis (C, H, and N), molar electrical conductivity, magnetic susceptibility measurement at room temperature, spectral methods (UV/vis and FTIR), as well as TG and DTA. The analytical data of the complexes show the formation of mononuclear complexes with general formula [Cu(L)cyc](ClO4)2?nH2O, (A): L = glycine, n = 1.5 and (B): L = alanine, n = 2.5. The tetradentate ligand cyclam was coordinated to metals through four N donors. The spectroscopic data suggested that the amino carboxylate ligands coordinated via their carboxylate ion moieties. The six-coordinate octahedral geometry around Cu(II) in both complexes was proposed. TG-DTA analysis indicates that complex B decomposes exothermally in a single step in the range of 310 -400 ?C . The cytotoxic activity of Cu(II) complexes and the starting ligands were tested against human cervix adenocarcinoma cell line (HeLa), human melanoma (FemX) and human colon carcinoma (LS174). The IC50 values for the Cu(II) complexes were from 48.35-82.25 ?M. Both complexes were tested for their antimicrobial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and the yeast Candida albicans.

Copper(II) and Zinc(II) Complexes with the Clinically Used Fluconazole: Comparison of Antifungal Activity and Therapeutic Potential

Copper(II) and zinc(II) complexes with clinically used antifungal drug fluconazole (fcz), {[CuCl2(fcz)2].5H2O}n, 1, and {[ZnCl2(fcz)2]·2C2H5OH}n, 2, were prepared and characterized by spectroscopic and crystallographic methods. The polymeric structure of the complexes comprises four fluconazole molecules monodentately coordinated via the triazole nitrogen and two chlorido ligands. With respect to fluconazole, complex 2 showed significantly higher antifungal activity against Candida krusei and Candida parapsilosis. All tested compounds reduced the total amount of ergosterol at subinhibitory concentrations, indicating that the mode of activity of fluconazole was retained within the complexes, which was corroborated via molecular docking with cytochrome P450 sterol 14α-demethylase (CYP51) as a target. Electrostatic, steric and internal energy interactions between the complexes and enzyme showed that 2 has higher binding potency to this target. Both complexes showed strong inhibition of C. albicans filamentation and biofilm formation at subinhibitory concentrations, with 2 being able to reduce the adherence of C. albicans to A549 cells in vitro. Complex 2 was able to reduce pyocyanin production in Pseudomonas aeruginosa between 10% and 25% and to inhibit its biofilm formation by 20% in comparison to the untreated control. These results suggest that complex 2 may be further examined in the mixed Candida-P. aeruginosa infections.

Innovative material containing the natural product curcumin, with enhanced antimicrobial properties for active packaging

Curcumin (Curc) reacts with zinc di‑iodine (ZnI₂) in 2:1molar ratio in the presence of an excess of a base triethylamine ((CH₃CH₂)₃N) in methanol (CH₃OH) solution towards the amorphous solid material of formula [ZnI₂(Curc)₂] (1). The complex was characterized by melting point (m.p.), Fourier Transform-Infra Red (FT-IR) and Nuclear Magnetic Resonance of hydrogen nucleus (¹H NMR) spectroscopy. The formula of 1 was determined by X-ray fluorescence (XRF) analysis. The retention of the structure in solution was confirmed by ¹H NMR spectroscopy. The antimicrobial activity of the complex has been studied against the bacteria Pseudomonas aeruginosa (PAO1). The Minimum Inhibitory Concentrations (MIC) of the compounds 1 and Curc against P. aeruginosa (PAO1) are: 71.3μΜ (75.3μg/mL) for [ZnI₂(Curc)₂] and 339μM (125μg/mL) for Curc, respectively. Moreover, the antimicrobial activity of the new material which was diffused in polystyrene against biofilm formed by PAO1 was also calculated.