Red-shifted and pH-responsive imidazole-based azo dyes with potent antimicrobial activity

Dantas, Daniela; Ribeiro, Ana Isabel; Carvalho, Filipe L.F.; Martins, Eva; Silva, Renata; Remião, Fernando; Zille, Andrea; Cerqueira, Fátima; Pinto, Eugénia; Dias, Alice

doi:10.1039/d3cc00372h

Cited by 6 publications

(20 citation statements)

References 33 publications

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“…The ( Z )-5-amino-1-methyl- N’ -phenyl-1 H -imidazole-4-carbohydrazonamide (Amz) was prepared in a four-step synthetic pathway using the commercial reagents DAMN, TEOF, methylamine, and phenylhydrazine [ 29 , 36 ]. €-5-amino-4-(imino(phenyldiazenyl)methyl)-1-methyl-1 H -imidazol-3-ium (AzoIz), ( E )-4-(ami€( E )-phenyldiazenyl)methylene)-5-imino- N,N, 1-trimethyl-4,5-dihydro-1 H -imidazol-2-amine (AzoIz.DMA), and ( E )-(5-imino-1-methyl-2-(piperidin-1-yl)-1,5-dihydro-4 H -imidazol-4-ylidene)(( E )-phenyldiazenyl)methanamine (AzoIz.Pip) were obtained from Amz and the commercial reagents silver nitrate and dimethylamine (DMA) or piperidine (Pip) through a two-step method presented in Figure 1 [ 30 ]. All compounds were characterized by 1 H NMR (Avance 3400, Bruker, MA, USA) before further tests, and the corresponding peaks were compared with the pure products previously characterized [ 29 , 30 ].…”

Section: Methodsmentioning

confidence: 99%

“…N -heterocycle scaffolds, such as imidazole rings, are readily available in nature and provide interesting biological functions such as antifungal, antibacterial, and anticancer activity [ 23 , 24 , 25 , 26 , 27 , 28 ]. In our research group, an unusual class of azo dyes containing 2-aminoimidazoles (AzoIz) was developed using 5-aminoimidazole 4-carboxamidrazones (Amz) as a precursor [ 29 , 30 ]. The initial Amz was oxidized using silver nitrate to obtain the AzoIz molecules.…”

Section: Introductionmentioning

confidence: 99%

“…The initial Amz was oxidized using silver nitrate to obtain the AzoIz molecules. Then, the reaction of the AzoIz with secondary amines, namely dimethylamine (DMA) and piperidine (Pip), gave rise to a novel class of substituted AzoIz (AzoIz.DMA and AzoIz.Pip) with remarkable substituent patterns in the heteroaryl unit [ 30 ]. The antimicrobial activity of the neutral form of these molecules was screened against Gram-positive and Gram-negative bacteria, filamentous fungi, and yeasts.…”

Section: Introductionmentioning

confidence: 99%

“…The compounds showed remarkable properties against Candida strains and against Cryptococcus neoformans and presented efficacy against biofilm formation. However, they were not effective against bacteria strains [ 29 , 30 , 31 , 32 ]. Moreover, the azoimidazole molecules also exhibited noteworthy halochromic properties, displaying strong colors that change from magenta to blue as the pH value decreases [ 30 ].…”

Section: Introductionmentioning

confidence: 99%

“…However, they were not effective against bacteria strains [ 29 , 30 , 31 , 32 ]. Moreover, the azoimidazole molecules also exhibited noteworthy halochromic properties, displaying strong colors that change from magenta to blue as the pH value decreases [ 30 ].…”

Section: Introductionmentioning

confidence: 99%

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Synergistic Antimicrobial Activity of Silver Nanoparticles with an Emergent Class of Azoimidazoles

et al. 2023

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The combination of two or more agents capable of acting in synergy has been reported as a valuable tool to fight against pathogens. Silver nanoparticles (AgNPs) present a strong antimicrobial action, although their cytotoxicity for healthy cells at active concentrations is a major concern. Azoimidazole moieties exhibit interesting bioactivities, including antimicrobial activity. In this work, a class of recently described azoimidazoles with strong antifungal activity was conjugated with citrate or polyvinylpyrrolidone-stabilized AgNPs. Proton nuclear magnetic resonance was used to confirm the purity of the compounds before further tests and atomic absorption spectroscopy to verify the concentration of silver in the prepared dispersions. Other analytical techniques elucidate the morphology and stability of AgNPs and corresponding conjugates, namely ultraviolet–visible spectrophotometry, scanning transmission electron microscopy and dynamic light scattering analysis. The synergistic antimicrobial activity of the conjugates was assessed through a checkerboard assay against yeasts (Candida albicans and Candida krusei) and bacteria (Staphylococcus aureus and Escherichia coli). The conjugates showed improved antimicrobial activity against all microorganisms, in particular towards bacteria, with concentrations below their individual minimal inhibitory concentration (MIC). Furthermore, some combinations were found to be non-cytotoxic towards human HaCaT cells.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Synergistic Antimicrobial Activity of Silver Nanoparticles with an Emergent Class of Azoimidazoles

et al. 2023

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Novel Nanoparticle‐Sized Cu(II), Ru(III), and Th(IV) Chelates Derived From Quinaldine Azo Dye Ligand: DFT Studies, Molecular Docking, and Applications in Drug Development and Catalysis

Khedr,

Gaber,

Elsharkawy

et al. 2024

Applied Organom Chemis

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Three novel complexes of copper(II), ruthenium(III), and thorium(IV) ions with quinaldine azo dye ligand HL were synthesized in nanoscale. Applying mass spectroscopy, electronic, infrared, 1H NMR, elemental, and thermal investigations, their structures were examined. By using azo nitrogen and hydroxyl oxygen atoms to coordinate as a monobasic bidentate, it was found that the ligand displayed bicapped square antiprism geometry with thorium(IV) metal ion, square pyramidal arrangement in copper(II) complex and octahedral configuration in ruthenium(III) complex. In order to confirm the complexes' geometrical arrangement, theoretical investigations were carried out using DFT/B3LYP/6–311 + G(d,p)/LANLDZ. The dipole moment, geometrical configuration, energetic parameters, and HOMO–LUMO gap of energy have been calculated. The compounds were formed in nanometric forms, as indicated by the mean particle sizes obtained by applying TEM. Based on TEM images for the complexes of copper(II), ruthenium(III), and thorium(IV), their average particle sizes were 11.04, 3.89, and 1.52 nm, respectively. PANC‐1 and A‐549 cells were used in the tests to evaluate the compounds' anticancer activity against the vinblastine reference. The findings confirm the great cytotoxicity effect of the free ligand and its complexes against the investigated cell lines using different doses of the examined compounds. Ru(III) and Cu(II) complexes exhibited cytotoxic effectiveness greater than that of vinblastine. The azo ligand, HL, exhibited the strongest antibacterial activity that is superior to that of the conventional medicines themselves and greater than that of its metal complexes. The most physiologically active compound's ideal conformation was found using molecular docking research, and the manner in which the Ru(III) complex and the enzyme of Panc‐1 link together was determined. It interacts in three different modes with the target receptor (PANC‐1): hydrophobic force, electrostatic force, and H‐bond. In addition to increasing the candidate activity, these interactions can be used to design and predict new, effective compounds. The capacity of the ligand and its complexes to act as heterogeneous catalysts for the oxidation of methyl violet 2B was examined. The ruthenium(III) and thorium(IV) complexes generated the greatest catalytic efficiencies.

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Synthesis of 6,8-diaminopurines via acid-induced cascade cyclization of 5-aminoimidazole precursors and preliminary anticancer evaluation

Senhorães,

Silva,

Sousa

et al. 2024

Org. Biomol. Chem.

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Red-shifted and pH-responsive imidazole-based azo dyes with potent antimicrobial activity

Abstract: A novel route is described to obtain 2 aminoimidazole azo dyes with unique substituents pattern in the heteroaryl unit that provides halochromic properties, exhibiting vibrant colours that change from magenta...

Cited by 6 publications

References 33 publications

Synergistic Antimicrobial Activity of Silver Nanoparticles with an Emergent Class of Azoimidazoles

Synergistic Antimicrobial Activity of Silver Nanoparticles with an Emergent Class of Azoimidazoles

Novel Nanoparticle‐Sized Cu(II), Ru(III), and Th(IV) Chelates Derived From Quinaldine Azo Dye Ligand: DFT Studies, Molecular Docking, and Applications in Drug Development and Catalysis

Synthesis of 6,8-diaminopurines via acid-induced cascade cyclization of 5-aminoimidazole precursors and preliminary anticancer evaluation

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