Novel 1, 2, 4-Triazoles as Antifungal Agents

Recent Research Progress in Oxime Insecticides and Perspectives for the Future

In recent decades, the unique structural attributes and purported insecticidal properties of oximes have garnered increasing attention. A variety of insecticides, encompassing fluxametamide, fluhexafon, and lepimectin, have been synthesized, all of which incorporate oximes. This review endeavors to encapsulate the insecticidal efficacy, structure-activity correlations, and operative mechanisms of oxime-containing compounds. Furthermore, it delves into the conceptual frameworks underpinning the design of innovative oxime-based insecticides, thereby shedding light on prospective advancements in this field.

Stereoselective Asymmetric Syntheses of Molecules with a 4,5-Dihydro-1H-[1,2,4]-Triazoline Core Possessing an Acetylated Carbohydrate Appendage: Crystal Structure, Spectroscopy, and Pharmacology

A new series of chiral 4,5-dihydro-1H-[1,2,4]-triazoline molecules, featuring a β-ᴅ-glucopyranoside appendage, were synthesized via a 1,3-dipolar cycloaddition reaction between various hydrazonyl chlorides and carbohydrate Schiff bases. The isolated enantiopure triazolines (8a-j) were identified through high-resolution mass spectrometry (HRMS) and vibrational spectroscopy. Subsequently, their solution structures were elucidated through NMR spectroscopic techniques. Single-crystal X-ray analysis of derivative 8b provided definitive evidence for the 3-D structure of this compound and revealed important intermolecular forces in the crystal lattice. Moreover, it confirmed the (S)-configuration at the newly generated stereo-center. Selected target compounds were investigated for anti-tumor activity in 60 cancer cell lines, with derivative 8c showing the highest potency, particularly against leukemia. Additionally, substituent-dependent anti-fungal and anti-bacterial behavior was observed.

Design and Synthesis of Eugenol Derivatives Bearing a 1,2,3-Triazole Moiety for Papaya Protection against Colletotrichum gloeosporioides

A series of 19 novel eugenol derivatives containing a 1,2,3-triazole moiety was synthesized via a two-step process, with the key step being a copper(I)-catalyzed azide-alkyne cycloaddition reaction. The compounds were assessed for their antifungal activities against Colletotrichum gloeosporioides, the causative agent of papaya anthracnose. Triazoles 2k, 2m, 2l, and 2n, at 100 ppm, were the most effective, reducing mycelial growth by 88.3, 85.5, 82.4, and 81.4%, respectively. Molecular docking calculations allowed us to elucidate the binding mode of these derivatives in the catalytic pocket of C. gloeosporioides CYP51. The best-docked compounds bind closely to the heme cofactor and within the channel access of the lanosterol (LAN) substrate, with crucial interactions involving residues Tyr102, Ile355, Met485, and Phe486. From such studies, the antifungal activity is likely attributed to the prevention of substrate LAN entry by the 1,2,3-triazole derivatives. The triazoles derived from natural eugenol represent a novel lead in the search for environmentally safe agents for controlling C. gloeosporioides.

Unraveling environmental effects in the absorption and fluorescence spectra of p-methoxyphenylpiperazine derivatives

The p-methoxyphenylpiperazine motif can be found in many biologically active molecules, including approved drugs. It is characterized by a relatively weak fluorescence, which can be employed in different types of studies involving molecules with this motif. In this work, a thorough analysis of the absorption, excitation and emission spectra of the diphenyl(aminomethyl)phosphine and tris(aminomethyl)phosphine derivatives of p-methoxyphenylpiperazine, supported by the DFT calculations (ωB97XD/6-311++G(d,p)) with NBO and QTAIM analysis also for different model molecules (e.g. 1-(4-methoxyphenyl)-4-methylpiperazine) enabled determination of the mechanisms underlying beneath the electronic transitions and allowed to rationalize mixed solvent effects observed in electronic spectra of the studied compounds. Electronic transition from the ground state to the first excited state can be regarded as the n,π → π* transition with no solvatochromic effects, however the hydrogen bonds between the HBD solvent molecules and the nitrogen atom bound directly to the aromatic ring (N(4)) are shifting strongly the 1st absorption or excitation band maxima to the higher energies. Fluorescence band, as a result of the electron transition from the equilibrated 1st excited state to the ground state, can be described as the π*→π with positive solvatochromism. N(4) in the excited states adopts a sp2 hybridization and is no longer able to form HBs. On the other hand, increased electron density on the aromatic ring makes the emission processes vulnerable to its direct environment.

Synthesis of Novel Fluoro Phenyl Triazoles Via Click Chemistry with or without Microwave Irradiation and their Evaluation as Anti-proliferative Agents in SiHa Cells

AIMS

Perform the synthesis of novel fluoro phenyl triazoles via click chemistry with or without microwave irradiation and their evaluation as anti-proliferative agents in SiHa cells.

BACKGROUND

Triazoles are heterocyclic compounds containing a five-member ring with two carbon and three nitrogen atoms. They are of great importance since many of them have shown to have biological activity as antifungal, antiviral, antibacterial, anti-HIV, anti-tuberculosis, vasodilator, and anticancer agents.

OBJECTIVES

Synthesize novel fluoro phenyl triazoles via click chemistry and evaluate their antiproliferative activity.

METHODS

First, several fluorophenyl azides were prepared. Reacting these aryl azides with phenylacetylene in the presence of Cu(I) catalyst, the corresponding fluoro phenyl triazoles were obtained by two methodologies, stirring at room temperature and under microwave irradiation at 40ºC. In addition, their antiproliferative activity was evaluated in cervical cancer SiHa cells.

RESULTS

Fluoro phenyl triazoles were obtained within minutes by means of microwave irradiation. The compound 3f, containing two fluorine atoms next to the carbon connected to the triazole ring, was the most potent among the fluoro phenyl triazoles tested in this study. Interestingly, the addition of a fluorine atom to the phenyl triazole structure in a specific site increases its antiproliferative effect as compared to parent phenyl triazole 3a without a fluorine atom.

CONCLUSION

Several fluoro phenyl triazoles were obtained by reacting fluoro phenyl azides with phenylacetylene in the presence of copper sulphate, sodium ascorbate and phenanthroline. Preparation of these triazoles with MW irradiation represents a better methodology since they are obtained within minutes and higher yields of cleaner compounds are obtained. In terms of biological studies, the proximity between fluorine atom and triazole ring increases its biological activity.

Synthesis, Structure, Biological Activity, and Luminescence Properties of a "Butterfly"-Type Silver Cluster with 3-Benzyl-4-phenyl-1,2,4-triazol-5-thiol

A new silver(I) cluster [Ag8L4(Py)(Pype)]·4Py·11H2O (I) with 3-benzyl-4-phenyl-1,2,4-triazol-5-thiol (L) was synthesized via the direct reaction of AgNO3 and L in MeOH, followed by recrystallization from a pyridine-piperidine mixture. The compound I was isolated in a monocrystal form and its crystal structure was determined via single crystal X-ray diffraction. The complex forms a "butterfly" cluster with triazol-5-thioles. The purity of the silver complex and its stability in the solution was confirmed via NMR analysis. Excitation and emission of the free ligand and its silver complex were studied at room temperature for solid samples. The in vitro biological activity of the free ligand and its complex was studied in relation to the non-pathogenic Mycolicibacterium smegmatis strain. Complexation of the free ligand with silver increases the biological activity of the former by almost twenty times. For the newly obtained silver cluster, a bactericidal effect was established.

Design, Synthesis, and Antifungal Activity of Novel 2-Ar-1,2,3-Triazole Derivatives

Triazoles are crucial molecular frameworks in the development of fungicidal compounds. Although there has been extensive research on triazole derivatives for fungicide discovery, the investigation of 2-Ar-substituted-1,2,3-triazoles remains in progress. This study reports the synthesis and evaluation of the fungicidal activity of 27 distinct 2-Ar-substituted-1,2,3-triazole derivatives. These derivatives were synthesized from anilines through a three-step process, with the key step being the Cu(II)-catalyzed annulation reaction of readily accessible alkyl 3-aminoacrylates with aryldiazonium salts. All derivatives were novel, and their structures were characterized using 1H NMR, 13C NMR, and high-resolution mass spectrometry. Their antifungal activity was tested against five phytopathogenic fungi. Twelve of the target compounds exhibited better performance than the positive control hymexazol in the fungal test. Notably, compound 6d demonstrated the most potent inhibition against Botryosphaeria dothidea with an EC50 value of 0.90 mg/L. The structure-activity relationships are also discussed in this paper. Preliminary studies on the antifungal mechanism of compound 6d revealed that it inhibits ergosterol synthesis and alters the morphology and ultrastructure of the B. dothidea mycelium. These results suggest that the designed 2-Ar-substituted-1,2,3-triazole-containing hydrazone derivatives warrant further investigation as potential lead compounds for novel antifungal agents.

Effectiveness of fluconazole as antifungal prophylaxis in cancer patients undergoing chemotherapy, radiotherapy, or immunotherapy: systematic review and meta-analysis

This review assessed the effectiveness of fluconazole as antifungal prophylaxis on the incidence of oral fungal diseases in patients undergoing cancer treatment. The secondary outcomes evaluated were the adverse effects, discontinuation of cancer therapy due to oral fungal infection, mortality by a fungal infection, and the mean duration of antifungal prophylaxis. Twelve databases and records were searched. The RoB 2 and ROBINS I tools were used to assess the risk of bias. The relative risk (RR), risk difference, and standard mean difference (SMD) were applied with 95% confidence intervals (CI). The certainty of the evidence was determined by GRADE. Twenty-four studies were included in this systematic review. In randomized controlled trials pooling, fluconazole was a protective factor for the primary outcome (RR = 0.30; CI: 0.16, 0.55; p < 0.01, vs placebo). Compared to other antifungals, fluconazole was only more effective than the subgroup of amphotericin B and nystatin (alone or in combination) (RR = 0.19; CI: 0.09, 0.43; p < 0.01). Fluconazole was also a protective factor in non-randomized trials pooling (RR = 0.19; CI: 0.05, 0.78; p = 0.02, vs untreated). The results showed no significant differences for the secondary outcomes. The certainty of the evidence was low and very low. In conclusion, prophylactic antifungals are necessary during cancer treatment, and fluconazole was shown to be more effective in reducing oral fungal diseases only compared with the subgroup assessing amphotericin B and nystatin, administered alone or in combination.

Nanotechnology-Based Strategies to Combat Multidrug-Resistant Candida auris Infections

An emerging multidrug-resistant pathogenic yeast called Candida auris has a high potential to spread quickly among hospitalized patients and immunodeficient patients causing nosocomial outbreaks. It has the potential to cause pandemic outbreaks in about 45 nations with high mortality rates. Additionally, the fungus has become resistant to decontamination techniques and can survive for weeks in a hospital environment. Nanoparticles might be a good substitute to treat illnesses brought on by this newly discovered pathogen. Nanoparticles have become a trend and hot topic in recent years to combat this fatal fungus. This review gives a general insight into the epidemiology of C. auris and infection. It discusses the current conventional therapy and mechanism of resistance development. Furthermore, it focuses on nanoparticles, their different types, and up-to-date trials to evaluate the promising efficacy of nanoparticles with respect to C. auris.

Benzimidazole-Triazole Hybrids as Antimicrobial and Antiviral Agents: A Systematic Review

Bacterial infections have attracted the attention of researchers in recent decades, especially due to the special problems they have faced, such as their increasing diversity and resistance to antibiotic treatment. The emergence and development of the SARS-CoV-2 infection stimulated even more research to find new structures with antimicrobial and antiviral properties. Among the heterocyclic compounds with remarkable therapeutic properties, benzimidazoles, and triazoles stand out, possessing antimicrobial, antiviral, antitumor, anti-Alzheimer, anti-inflammatory, analgesic, antidiabetic, or anti-ulcer activities. In addition, the literature of the last decade reports benzimidazole-triazole hybrids with improved biological properties compared to the properties of simple mono-heterocyclic compounds. This review aims to provide an update on the synthesis methods of these hybrids, along with their antimicrobial and antiviral activities, as well as the structure-activity relationship reported in the literature. It was found that the presence of certain groups grafted onto the benzimidazole and/or triazole nuclei (-F, -Cl, -Br, -CF₃, -NO₂, -CN, -CHO, -OH, OCH₃, COOCH₃), as well as the presence of some heterocycles (pyridine, pyrimidine, thiazole, indole, isoxazole, thiadiazole, coumarin) increases the antimicrobial activity of benzimidazole-triazole hybrids. Also, the presence of the oxygen or sulfur atom in the bridge connecting the benzimidazole and triazole rings generally increases the antimicrobial activity of the hybrids. The literature mentions only benzimidazole-1,2,3-triazole hybrids with antiviral properties. Both for antimicrobial and antiviral hybrids, the presence of an additional triazole ring increases their biological activity, which is in agreement with the three-dimensional binding mode of compounds. This review summarizes the advances of benzimidazole triazole derivatives as potential antimicrobial and antiviral agents covering articles published from 2000 to 2023.

Green Synthesis of Aromatic Nitrogen-Containing Heterocycles by Catalytic and Non-Traditional Activation Methods

Recent advances in the environmentally benign synthesis of aromatic N-heterocycles are reviewed, focusing primarily on the application of catalytic methods and non-traditional activation. This account features two main parts: the preparation of single ring N-heterocycles, and their condensed analogs. Both groups include compounds with one, two and more N-atoms. Due to the large number of protocols, this account focuses on providing representative examples to feature the available methods.

Synthesis, Biological Evaluation, and Molecular Modeling Studies of New 1,3,4-Thiadiazole Derivatives as Potent Antimicrobial Agents

In this work, the synthesis, characterization, and biological activities of a new series of 1,3,4-thiadiazole derivatives were investigated. The structures of final compounds were identified using ¹ H-NMR, ¹³ C-NMR, elemental analysis, and HRMS. All the new synthesized compounds were then screened for their antimicrobial activity against four types of pathogenic bacteria and one fungal strain, by application of the MIC assays, using Ampicilin, Gentamycin, Vancomycin, and Fluconazole as standards. Among the compounds, the MIC values of 4 and 8 μg/mL of the compounds 3f and 3g, respectively, are remarkable and indicate that these compounds are good candidates for antifungal activity. The docking experiments were used to identify the binding forms of produced ligands with sterol 14-demethylase to acquire insight into relevant proteins. The MD performed about 100 ns simulations to validate selected compounds' theoretical studies. Finally, using density functional theory (DFT) to predict reactivity, the chemical characteristics and quantum factors of synthesized compounds were computed. These results were then correlated with the experimental data. Furthermore, computational estimation was performed to predict the ADME properties of the most active compound 3f.

Synthesis of Benzimidazole-1,2,4-triazole Derivatives as Potential Antifungal Agents Targeting 14α-Demethylase

Invasive fungal infections (IFIs) are increasing as major infectious diseases around the world, and the limited efficacy of existing medications has resulted in substantial morbidity and death in patients due to the lack of effective antifungal agents and serious drug resistance. In this study, a series of benzimidazole-1,2,4-triazole derivatives (6a-6l) were synthesized and characterized by ¹H NMR, ¹³C NMR, and HR-MS spectral analysis. All the target compounds were screened for their in vitro antifungal activity against four fungal strains, namely, C. albicans, C. glabrata, C. krusei, and C. parapsilopsis. The synthesized compounds exhibited significant antifungal potential, especially against C. glabrata. Three compounds (6b, 6i, and 6j) showed higher antifungal activity with their MIC values (0.97 μg/mL) compared with voriconazole and fluconazole. Molecular docking provided a possible binding mode of compounds 6b, 6i, and 6j in the 14α-demethylase active site. Our studies suggested that the benzimidazole-1,2,4-triazole derivatives can be used as a new fungicidal lead targeting 14α-demethylase for further structural optimization. In addition, their effects on the L929 cell line were also investigated to evaluate the cytotoxic effects of the compounds. SEM analyses were performed to examine the effects of compounds 6a, 6i, and 6j on C. glabrata cells under in vivo experimental conditions.

Antifungal Activity of a Library of Aminothioxanthones

Fungal infections are one of the main causes of mortality and morbidity worldwide and taking into account the increasing incidence of strains resistant to classical antifungal drugs, the development of new agents has become an urgent clinical need. Considering that thioxanthones are bioisosteres of xanthones with known anti-infective actions, their scaffolds were selected for this study. A small library of synthesized aminothioxanthones (1-10) was evaluated for in vitro antifungal activity against Candida albicans, Aspergillus fumigatus, and Trichophyton rubrum; for the active compounds, the spectrum was further extended to other clinically relevant pathogenic fungi. The results showed that only compounds 1, 8, and 9 exhibited inhibitory and broad-spectrum antifungal effects. Given the greater antifungal potential presented, compound 1 was the subject of further investigations to study its anti-virulence activity and in an attempt to elucidate its mechanism of action; compound 1 seems to act predominantly on the cellular membrane of C. albicans ATCC 10231, altering its structural integrity, without binding to ergosterol, while inhibiting two important virulence factors-dimorphic transition and biofilm formation-frequently associated with C. albicans pathogenicity and resistance. In conclusion, the present work proved the usefulness of thioxanthones in antifungal therapy as new models for antifungal agents.

New Derivatives of 5-((1-Methyl-Pyrrol-2-yl) Methyl)-4-(Naphthalen-1-yl)-1,2,4-Triazoline-3-Thione and Its Coordination Compounds with Anticancer Activity

A new ligand 5-((1-methyl-pyrrol-2-yl) methyl)-4-(naphthalen-1-yl)-1,2,4-triazoline-3-thione (C15) and its metal complexes with formulae: Mn(C15)Cl₂MeOH (1), Fe(C15)Cl₂MeOH (2), Ni(C15)Cl₂MeOH (3), Cu(C15)₂Cl₂ (4) and Zn(C15)₄Cl₂ (5) have been synthesized. The C15 ligand and complexes were characterized by NMR, elemental analysis, FT-IR, EPR, magnetic and TGA studies. The anticancer activities of the organic ligand (C15) and complexes (1–5) were evaluated against human colon adenocarcinoma (HT29) and human lung (A549) cancer cell lines. The complex (1) exhibited potential activity at concentration of 794.37 μM (A549) and 654.31 μM (HT29) in both cancer cells. The complex (3) showed significant activity against the HT29 cancer cell line with an IC₅₀ value of 1064.05 μM. This article highlights some of the metals that have become important in the development of new coordination complexes and the treatment of cancer. Additionally, for C15, the toxicity was predicted by ADMET analysis and molecular docking.

Acridine Based N-Acylhydrazone Derivatives as Potential Anticancer Agents: Synthesis, Characterization and ctDNA/HSA Spectroscopic Binding Properties

A series of novel acridine N-acylhydrazone derivatives have been synthesized as potential topoisomerase I/II inhibitors, and their binding (calf thymus DNA—ctDNA and human serum albumin—HSA) and biological activities as potential anticancer agents on proliferation of A549 and CCD-18Co have been evaluated. The acridine-DNA complex 3b (-F) displayed the highest Kb value (Kb = 3.18 × 103 M−1). The HSA-derivatives interactions were studied by fluorescence quenching spectra. This method was used for the calculation of characteristic binding parameters. In the presence of warfarin, the binding constant values were found to decrease (KSV = 2.26 M−1, Kb = 2.54 M−1), suggesting that derivative 3a could bind to HSA at Sudlow site I. The effect of tested derivatives on metabolic activity of A549 cells evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide or MTT assay decreased as follows 3b(-F) > 3a(-H) > 3c(-Cl) > 3d(-Br). The derivatives 3c and 3d in vitro act as potential dual inhibitors of hTopo I and II with a partial effect on the metabolic activity of cancer cells A594. The acridine-benzohydrazides 3a and 3c reduced the clonogenic ability of A549 cells by 72% or 74%, respectively. The general results of the study suggest that the novel compounds show potential for future development as anticancer agents.