Design and synthesis of imidazolo-1, 2,3-triazoles hybrid compounds by microwave-assisted method: Evaluation as an antioxidant and antimicrobial agents and molecular docking studies

Click chemistry beyond metal-catalyzed cycloaddition as a remarkable tool for green chemical synthesis of antifungal medications

Click chemistry is widely used for the efficient synthesis of 1,4-disubstituted-1,2,3-triazole, a well-known scaffold with widespread biological activity in the pharmaceutical sciences. In recent years, this magic ring has attracted the attention of scientists for its potential in designing and synthesizing new antifungal agents. Despite scientific and medical advances, fungal infections still account for more than 1.5 million deaths globally per year, especially in people with compromised immune function. This increasing trend is definitely related to a raise in the incidence of fungal infections and prevalence of antifungal drug resistance. In this condition, an urgent need for new alternative antifungals is undeniable. By focusing on the main aspects of reaction conditions in click chemistry, this review was conducted to classify antifungal 1,4-disubstituted-1,2,3-triazole hybrids based on their chemical structures and introduce the most effective triazole antifungal derivatives. It was notable that in all reactions studied, Cu(I) catalysts generated in situ by the reduction in Cu(II) salts or used copper(I) salts directly, as well as mixed solvents of t-BuOH/H2O and DMF/H2O had most application in the synthesis of triazole ring. The most effective antifungal activity was also observed in fluconazole analogs containing 1,2,3-triazole moiety and benzo-fused five/six-membered heterocyclic conjugates with a 1,2,3-triazole ring, even with better activity than fluconazole. The findings of structure-activity relationship and molecular docking of antifungal derivatives synthesized with copper-catalyzed azide-alkyne cycloaddition (CuAAC) could offer medicinal chemistry scientists valuable data on designing and synthesizing novel triazole antifungals with more potent biological activities in their future research.

One-pot synthesis, NMR, quantum chemical approach, molecular docking studies, drug-likeness and in-silico ADMET prediction of novel 1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-2-(furan-2-yl)-4,5-diphenyl-1H-imidazole derivatives

A novel drug to treat SARS-CoV-2 infections and hydroxyl chloroquine analogue, 1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-2-(furan-2-yl)-4,5-diphenyl-1H-imidazole (DDFDI) compound has been synthesized in one pot reaction. The novel compound DDFDI had been characterized by FT-IR, ¹H-NMR and ¹³C-NMR spectral techniques. The geometrical structure was optimized by density functional theory (DFT) method at B3LYP/6-31G (d, p) as the basis set. The smaller energy value provides the higher reactivity of DDFDI compound than hydroxyl chloroquine and was corrected by high electrophilic and low nucleophilic reactions. The stability and charge delocalization of the molecule were also considered by natural bond orbital (NBO) analysis. The HOMO-LUMO energies describe the charge transfer which takes place within the molecule. Molecular electrostatic potential has also been analysed. Drug likeness and oral activity have been carried out based on Lipinski's rule of five. Molecular docking studies are implemented to analyse the binding energy of the DDFDI compound against Covid-19/6W41, COVID-19/6WCF, COVID-19/6Y84 and COVID-19/6W4B receptors and found to be considered as a better antiviral agents.

Design, Synthesis, Anticancer Activity and Molecular Docking of New 1,2,3-Triazole-Based Glycosides Bearing 1,3,4-Thiadiazolyl, Indolyl and Arylacetamide Scaffolds

New 1,3,4-thiadiazole thioglycosides linked to a substituted arylidine system were synthesized via heterocyclization via click 1,3-dipolar cycloaddition. The click strategy was used for the synthesis of new 1,3,4-thiadiazole and 1,2,3-triazole hybrid glycoside-based indolyl systems as novel hybrid molecules by reacting azide derivatives with the corresponding acetylated glycosyl terminal acetylenes. The cytotoxic activities of the compounds were studied against HCT-116 (human colorectal carcinoma) and MCF-7 (human breast adenocarcinoma) cell lines using the MTT assay. The results showed that the key thiadiazolethione compounds, the triazole glycosides linked to p-methoxyarylidine derivatives and the free hydroxyl glycoside had potent activity comparable to the reference drug, doxorubicin, against MCF-7 human cancer cells. Docking simulation studies were performed to check the binding patterns of the synthesized compounds. Enzyme inhibition assay studies were also conducted for the epidermal growth factor receptor (EGFR), and the results explained the activity of a number of derivatives.

CDATA[Recent Advances in the Development of 1,2,3-Triazole-containing Derivatives as Potential Antifungal Agents and Inhibitors of Lanoster ol 14α-Demethylase

1,2,3-Triazole, a five-membered heterocyclic nucleus, is widely recognized as a key chromophore of great value in medicinal chemistry for delivering compounds possessing innumerable biological activities, including antimicrobial, antitubercular, antidiabetic, antiviral, antitumor, antioxidants, and anti-inflammatory activities. Mainly, in the past years, diverse conjugates carrying this biologically valuable core have been reported due to their attractive fungicidal potential and potent effects on various infective targets. Hence, hybridization of 1,2,3-triazole with other antimicrobial pharmacophores appears to be a judicious strategy to develop new effective anti-fungal candidates to combat the emergence of drug-sensitive and drug-resistant infectious diseases. Thus, the current review highlights the recent advances of this promising category of 1,2,3-triazole-containing hybrids incorporating diverse varieties of bioactive heterocycles such as conozole, coumarin, imidazole, benzimidazole, pyrazole, indole, oxindole, chromene, pyrane, quinazoline, chalcone, isoflavone, carbohydrates, and amides. It underlies their inhibition behavior against a wide array of infectious fungal species during 2015-2020.

A novel method for explaining the product inhibition mechanisms via molecular docking: inhibition studies for tyrosinase from Agaricus bisporus

The present study aims to investigate the substrate (4-methyl catechol and catechol) specificity and inhibition mechanisms (l-ascorbic acid, citric acid, and l-cysteine) of the tyrosinase enzyme (TYR), which is held responsible for browning in foods and hyperpigmentation in the human skin, through kinetic and molecular docking studies. During the experimental studies, the diphenolase activities of TYR were determined, following which the inhibitory effects of the inhibitors upon the diphenolase activities of TYR. The inhibition types were determined as competitively for l-ascorbic acid and citric acid and noncompetitive for l-cysteine. The kinetic results showed that the substrate specificity was better for catechol while l-cysteine showed the best inhibition profile. As for the in silico studies, they also showed that catechol had a better affinity in line with the experimental results of this study, considering the interactions of the substrates with TYR's active site residues and their distance to CuB metal ion, which is an indicator of diphenolase activity. Besides, the inhibitory mechanisms of the inhibitor molecules were explained by the molecular modeling studies, considering the binding number of the inhibitors with the active site amino acid residues of TYR, the number and length of H bonds, negative binding energy values, and their distance to CuB metal ion. Based on our results, we suggest that the novel method used in this study to explain the inhibitory mechanism of l-cysteine may provide an affordable alternative to the expensive methods available for explaining the inhibitory mechanism of TYR and those of other enzymes. HighlightsThe best affinity for the tyrosinase enzyme occurred with catechol.l-Ascorbic acid, citric acid, l-cysteine inhibited the diphenolic activity of tyrosinase.In silico studies confirmed the best affinity shown by catechol.Product inhibition mechanism of l-cysteine explained by in silico for the first time.Communicated by Ramaswamy H. Sarma.

Synthesis and therapeutic potential of imidazole containing compounds

Imidazole is a five-membered heterocyclic moiety that possesses three carbon, two nitrogen, four hydrogen atoms, and two double bonds. It is also known as 1, 3-diazole. It contains two nitrogen atoms, in which one nitrogen bear a hydrogen atom, and the other is called pyrrole type nitrogen. The imidazole name was reported by Arthur Rudolf Hantzsch (1857–1935) in 1887. 1, 3-diazole is an amphoteric in nature i.e. it shows both acidic and basic properties. It is a white or colorless solid that is highly soluble in water and other polar solvents. Due to the presence of a positive charge on either of two nitrogen atom, it shows two equivalent tautomeric forms. Imidazole was first named glyoxaline because the first synthesis has been made by glyoxal and ammonia. It is the basic core of some natural products such as histidine, purine, histamine and DNA based structures, etc. Among the different heterocyclic compounds, imidazole is better known due to its broad range of chemical and biological properties. Imidazole has become an important synthon in the development of new drugs. The derivatives of 1, 3-diazole show different biological activities such as antibacterial, antimycobacterial, anti-inflammatory, antitumor, antidiabetic, anti-allergic, antipyretic, antiviral, antioxidant, anti-amoebic, antihelmintic, antifungal and ulcerogenic activities, etc. as reported in the literature. There are different examples of commercially available drugs in the market which contains 1, 3-diazole ring such as clemizole (antihistaminic agent), etonitazene (analgesic), enviroxime (antiviral), astemizole (antihistaminic agent), omeprazole, pantoprazole (antiulcer), thiabendazole (antihelmintic), nocodazole (antinematodal), metronidazole, nitroso-imidazole (bactericidal), megazol (trypanocidal), azathioprine (anti rheumatoid arthritis), dacarbazine (Hodgkin's disease), tinidazole, ornidazole (antiprotozoal and antibacterial), etc. This present review summarized some pharmacological activities and various kinds of synthetic routes for imidazole and their derived products.

Agar-entrapped sulfonated DABCO: Agelly acidic catalyst for the acceleration of one-pot synthesis of 1,2,4-triazoloquinazolinone and some pyrimidine derivatives

In this project, a recently synthesized DABCO-based catalyst is entrapped in agar to reduce its moisture sensitivity leading to enhancement of its stability and catalytic activity. After preparation and identification this new reagent is used as an efficient and environmentally safe catalyst for the preparation of 1, 2, 4-triazoloquinazolinone and some pyrimidine derivatives. This method is accompanied with some superiorities such as, simple operation, mild and green conditions, use of low cost and non-hazardous natural material, short reaction times, easy preparation methods and simple work-up procedures. The prepared catalyst can be re-used for several times in all of the studied reactions without any appreciable loss in its activity.

Synthesis of novel 1,2,3 triazole derivatives and assessment of their potential cholinesterases, glutathione S-transferase enzymes inhibitory properties: An in vitro and in silico study

In this study, new 1,2,3-triazole derivatives containing chalcone core (1-7) were synthesized. Obtained compounds were characterized by IR, ¹H NMR, ¹³C NMR, and mass studies. Characterized compounds (1-7) inhibitory effects were tested against the glutathione S-transferase (GST), acetylcholinesterase (AChE), and Butyrylcholinesterase (BChE). Their K_i values were in the range of 5.88-11.13 µM on AChE, 5.08-15.12 µM on BChE, and 9.82-13.22 µM on GST. Remarkable inhibitory effects were obtained against three tested metabolic enzymes. Also, binding scores of the best-inhibitors against AChE, BChE, and GST enzymes were detected as -9.969 kcal/mol, -10.672 kcal/mol, and -8.832 kcal/mol, respectively. Isoindoline-1,3-dione and benzothiophene moieties played a critical role in the inhibition of AChE and BChE enzymes, respectively. Phenylene and triazole moieties had the most important interactions for inhibition of the GST enzyme. Therefore, in vivo and in silico results indicated that these compounds can be considered in drug design processes for the treatment of some diseases including Alzheimer's disease (AD), leukemia, and some type of cancer.

Recent accomplishments on the synthetic/biological facets of pharmacologically active 1H-1,2,3-triazoles

The continuous demand of medicinally important scaffolds has prompted the synthetic chemists to identify simple and efficient routes for their synthesis. 1H-1,2,3-triazole, obtained by highly versatile, efficacious and selective "Click Reaction" has become a synthetic/medicinal chemist's favorite not only because of its ability to mimic different functional groups but also due to enhancement in the targeted biological activities. Triazole ring has also been shown to play a critical role in biomolecular mimetics, fragment-based drug design, and bioorthogonal methodologies. In addition, the availability of triazole containing drugs such as fluconazole, furacyclin, etizolam, voriconazole, triozolam etc. in market has underscored the potential of this biologically enriched core in expediting development of new scaffolds. The present review, therefore, is an attempt to highlight the recent synthetic/biological advancements in triazole derivatives that could facilitate the in-depth understanding of its role in the drug discovery process.

An Updated Review on the Synthesis and Antibacterial Activity of Molecular Hybrids and Conjugates Bearing Imidazole Moiety

The rapid growth of serious infections caused by antibiotic resistant bacteria, especially the nosocomial ESKAPE pathogens, has been acknowledged by Governments and scientists and is one of the world's major health problems. Various strategies have been and are currently investigated and developed to reduce and/or delay the bacterial resistance. One of these strategies regards the design and development of antimicrobial hybrids and conjugates. This unprecedented critical review, in which our continuing interest in the synthesis and evaluation of the bioactivity of imidazole derivatives is testified, aims to summarise and comment on the results obtained from the end of the 1900s until February 2020 in studies conducted by numerous international research groups on the synthesis and evaluation of the antibacterial properties of imidazole-based molecular hybrids and conjugates in which the pharmacophoric constituents of these compounds are directly covalently linked or connected through a linker or spacer. In this review, significant attention was paid to summarise the strategies used to overcome the antibiotic resistance of pathogens whose infections are difficult to treat with conventional antibiotics. However, it does not include literature data on the synthesis and evaluation of the bioactivity of hybrids and conjugates in which an imidazole moiety is fused with a carbo- or heterocyclic subunit.

Anti-Tubercular Properties of 4-Amino-5-(4-Fluoro-3- Phenoxyphenyl)-4H-1,2,4-Triazole-3-Thiol and Its Schiff Bases: Computational Input and Molecular Dynamics

In the present investigation, the parent compound 4-amino-5-(4-fluoro-3-phenoxyphenyl)-4H-1,2,4-triazole-3-thiol (1) and its Schiff bases 2, 3, and 4 were subjected to whole-cell anti-TB against H37Rv and multi-drug-resistant (MDR) strains of Mycobacterium tuberculosis (MTB) by resazurin microtiter assay (REMA) plate method. Test compound 1 exhibited promising anti-TB activity against H37Rv and MDR strains of MTB at 5.5 µg/mL and 11 µg/mL, respectively. An attempt to identify the suitable molecular target for compound 1 was performed using a set of triazole thiol cellular targets, including β-ketoacyl carrier protein synthase III (FABH), β-ketoacyl ACP synthase I (KasA), CYP121, dihydrofolate reductase, enoyl-acyl carrier protein reductase, and N-acetylglucosamine-1-phosphate uridyltransferase. MTB β-ketoacyl ACP synthase I (KasA) was identified as the cellular target for the promising anti-TB parent compound 1 via docking and molecular dynamics simulation. MM(GB/PB)SA binding free energy calculation revealed stronger binding of compound 1 compared with KasA standard inhibitor thiolactomycin (TLM). The inhibitory mechanism of test compound 1 involves the formation of hydrogen bonding with the catalytic histidine residues, and it also impedes access of fatty-acid substrates to the active site through interference with α5–α6 helix movement. Test compound 1-specific structural changes at the ALA274–ALA281 loop might be the contributing factor underlying the stronger anti-TB effect of compound 1 when compared with TLM, as it tends to adopt a closed conformation for the access of malonyl substrate to its binding site.

Benefits and applications of microwave-assisted synthesis of nitrogen containing heterocycles in medicinal chemistry

Nitrogen containing heterocycles are of immense research interest because they are often found as naturally occurring bioactive compounds.