1,2,4-Triazoles as Important Antibacterial Agents

AgNOx as Nitrogen Source for [1+1+3] Cycloaddition of Isocyanides with Isocyanates: Selective Synthesis of 1,2,4-Triazoles

A novel [1+1+3] annulation of AgNOx, isocyanides, and isocyanates for the selective synthesis of 1,2,4-triazoles is presented herein. In this transformation, AgNOx and isocyanates are used as nitrogen sources instead of the traditional hydrazine or diazonium reagents. This process also involves N-O/C-H/C═N bond cleavage and the construction of new N-N/C-N bonds with a good substrate scope and functional group tolerance.

Synthesis, α-glucosidase inhibitory activity, and molecular dynamic simulation of 6-chloro-2-methoxyacridine linked to triazole derivatives

Α-glucosidase inhibition can be useful in the management of carbohydrate-related diseases, especially type 2 diabetes mellitus. Therefore, in this study, a new series of 6-chloro-2-methoxyacridine bearing different aryl triazole derivatives were designed, synthesized, and evaluated as potent α-glucosidase inhibitors. The most potent derivative in this group was 7h bearing para-fluorine with IC50 values of 98.0 ± 0.3 µM compared with standard drug acarbose (IC50 value = 750.0 ± 10.5 μM). A kinetic study of compound 7h revealed that it is a competitive inhibitor against α-glucosidase. Molecular dynamic simulations of the most potent derivative were also executed and indicated suitable interactions with residues of the enzyme which rationalized the in vitro results.

Significance of Triazole in Medicinal Chemistry: Advancement in Drug Design, Reward and Biological Activity

One of the triazole tautomers, 1,2,4-triazole derivatives, has a wide range of biological activities that suggest its potential therapeutic utility in medicinal chemistry. These actions include anti-inflammatory, anti-cancer, anti-bacterial, anti-tuberculosis, and anti-diabetic effects. Using computational simulations and models, we investigate the structure-activity relationships of 1,2,4-triazoles, showing how various modifications to the triazole core yield a variety of clinical therapeutic benefits. The review highlights the anti-inflammatory effect of 1,2,4-triazoles in relation to their ability to disrupt significant inflammatory mediators and pathways. We present in-silico data that illuminate the triazoles' capacity to inhibit cell division, encourage apoptosis, and stop metastasis in a range of cancer models. This review looks at the bactericidal and bacteriostatic properties of 1,2,4-triazole derivatives, with a focus on their potential efficacy against multi-drug resistant bacterial infections and their usage in tuberculosis therapy. In order to better understand these substances' potential anti-diabetic benefits, this review also looks at how they affect glucose metabolism regulation and insulin responsiveness. Coordinated efforts are required to translate the efficacy of 1,2,4-triazole compounds in preclinical models into practical therapeutic benefits. Based on the information provided, it can be concluded that 1,2,4-triazole derivatives are a promising class of diverse therapeutic agents with potential utility in a range of disorders. Their development and improvement might herald a new era of medical care that will be immensely advantageous to both patients and the medical community as a whole. This comprehensive research, which is further reinforced by in-silico investigations, highlights the great medicinal potential of 1,2,4-triazoles. Additionally, this study encourages more research into these substances and their enhancement for use in pharmaceutical development.

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.

Construction and Docking Studies of Novel Pyrimido[4,5-b]quinolines as Antimicrobial Agents

In order to develop novel antimicrobial agents, we prepared quinoline bearing pyrimidine analogues 2-7, 8 a-d and 9 a-d and their structures were elucidated by spectroscopic techniques. Furthermore, our second aim was to predict the interactions between the active compounds and enzymes (DNA gyrase and DHFR). In this work, fourteen pyrimido[4,5-b]quinoline derivatives were prepared and assessed for their antimicrobial potential by estimating zone of inhibition. All the screened candidates displayed antibacterial potential with zone of inhibition range of 9-24 mm compared with ampicillin (20-25 mm) as a reference drug. Moreover, the target derivatives 2 (ZI=16), 9 c (ZI=17 mm) and 9 d (ZI=16 mm) recorded higher antifungal activity against C. albicans to that exhibited by the antifungal drug amphotericin B (ZI=15 mm). Finally, the most potent pyrimidoquinoline compounds (2, 3, 8 c, 8 d, 9 c and 9 d) were docked inside DHFR and DNA gyrase active sites and they recorded excellent fitting within the active regions of DNA gyrase and DHFR. These outcomes revealed us that compounds (2, 3, 8 c, 8 d, 9 c and 9 d) could be lead compounds to discover novel antibacterial candidates.

Bioactivity and molecular docking studies of selected plant compounds

BACKGROUND

The shortcomings of synthetic pesticides are becoming increasingly evident. In the pursuit of looking for alternative, environmentally friendly pesticides, the potential use of two naturally occurring sesquiterpenes, α-bisabolol and bisabolol oxide A, as bactericides or acaricides, was investigated against three gram-positive and three gram-negative bacteria, and the eggs and larvae of the cattle tick Hyalomma scupense, respectively. The primary targeted site of synthetic insecticides is acetylcholinesterase (AChE), so the inhibitory activity of both sesquiterpenes was evaluated. Then, molecular docking and molecular mechanics generalized Born surface area (MM-GBSA) studies were performed to gain insight into their binding mode in the AChE active site.

RESULTS

Bisabolol oxide A showed good activity against Staphylococcus aureus, Escherichia coli, and Salmonella enteritidis with inhibition zones ranging from 16 to 34 mm and minimal inhibitory concentration (CIM) of 3.125  mg mL-1. Ovicidal and larvicidal assays revealed promising activity of α-bisabolol and bisabolol oxide A against H. scupense, with bisabolol oxide A being more effective against larval ticks with lethal concentration (LC50) value of 0.78%. Both compounds also displayed potent anti-AChE activity with inhibition concentration (IC50) values of 37.09 and 28.14 μg mL-1, respectively. Furthermore, α-bisabolol and bisabolol oxide A exhibited good and comparable docking scores (-7.289 and -7.139 Kcal mol-1, respectively) and were found to accommodate in the active-site gorge of AChE via hydrogen bonding and hydrophobic interactions.

CONCLUSION

Bisabolol oxide A and, to a lesser degree, α-bisabolol are active against bacteria and ectoparasites and may represent an economical and sustainable alternative to toxic synthetic pesticides to control pathogens. © 2024 Society of Chemical Industry.

New 1H-1,2,4-Triazolyl Derivatives as Antimicrobial Agents

New 1H-1,2,4-triazolyl derivatives were synthesized, and six of them were selected based on docking prediction for the investigation of their antimicrobial activity against five bacterial and eight fungal strains. All compounds demonstrated antibacterial activity with MIC lower than that of the ampicillin and chloramphenicol. In general, the most sensitive bacteria appeared to be P. fluorescens, while the plant pathogen X. campestris was the most resistant. The antifungal activity of the compounds was much better than the antibacterial activity. All compounds were more potent (6 to 45 times) than reference drugs ketoconazole and bifonazole with the best activity achieved by compound 4 a. A. versicolor, A. ochraceus, A.niger, and T.viride showed the highest sensitivity to compound 4 b, while, T. viride, P. funiculosum, and P.ochrochloron showed good sensitivity to compound 4 a. Molecular docking studies suggest that the probable mechanism of antibacterial activity involves the inhibition of the MurB enzyme of E. coli, while CYP51 of C. albicans appears to be involved in the mechanism of antifungal activity. It is worth mentioning that none of the tested compounds violated Lipinski's rule of five.

Copper supported modified magnetic carrageenan as a bio-based catalyst for the synthesis of novel scaffolds bearing the 1,2,3-triazole unit through the click reaction

The ongoing work delineates the design of a novel library of 1,2,3-triazole-attached phenylacetamides through molecular hybridization of propargyl and phenylacetamide derivatives. Copper-supported modified magnetic carrageenan serves as a green heterogeneous catalyst, ensuring high yield, efficient reaction times, high atom economy, utilization of an environmentally friendly catalyst from a natural source, and a straightforward workup procedure. The successful synthesis of the catalyst is confirmed and evaluated using various analytical techniques, while the synthetic compounds are characterized through 1H NMR and 13C NMR.

Triazole derivatives as potential xanthine oxidase inhibitors: Design, enzyme inhibition potential, and docking studies

Considerable ingenuity has been shown in the recent years in the discovery of novel xanthine oxidase (XO) inhibitors that fall outside the purine scaffold. The triazole nucleus has been the cornerstone for the development of many enzyme inhibitors for the clinical management of several diseases, where hyperuricemia is one of them. Here, we give a critical overview of significant research on triazole-based XO inhibitors, with respect to their design, synthesis, inhibition potential, toxicity, and docking studies, done till now. Based on these literature findings, we can expect a burst of modifications on triazole-based scaffolds in the near future by targeting XO, which will treat hyperuricemics, that is, painful conditions like gout that at present are hard to deal with.

1,2,3-Triazole Hybrids Containing Isatins and Phenolic Moieties: Regioselective Synthesis and Molecular Docking Studies

The synthesis of hybrid molecules is one of the current strategies of drug discovery for the development of new lead compounds. The 1,2,3-triazole moiety represents an important building block in Medicinal Chemistry, extensively present in recent years. In this paper, we presented the design and the synthesis of new 1,2,3-triazole hybrids, containing both an isatine and a phenolic core. Firstly, the non-commercial azide and the alkyne synthons were prepared by different isatines and phenolic acids, respectively. Then, the highly regioselective synthesis of 1,4-disubstituted triazoles was obtained in excellent yields by a click chemistry approach, catalyzed by Cu(I). Finally, a molecular docking study was performed on the hybrid library, finding four different therapeutic targets. Among them, the most promising results were obtained on 5-lipoxygenase, an enzyme involved in the inflammatory processes.

Exploration of nonlinear optical properties of 4-methyl-4H-1,2,4-triazol-3-yl)thio)-N-phenylpropanamide based derivatives: experimental and DFT approach

Triazoles, nitrogen-containing heterocycles, have gained attention for their applications in medicinal chemistry, drug discovery, agrochemicals, and material sciences. In the current study, we synthesized novel derivatives of N-substituted 2-((5-(3-bromophenyl)-4-methyl-4H-1,2,4-triazol-3-yl)thio)-N-phenylpropanamide and conducted a comprehensive investigation using density functional theory (DFT). These novel structural hybrids of 1,2,4-triazole were synthesized through the multi-step chemical modifications of 3-bromobenzoic acid (1). Initially, compound 1 was converted into its methyl-3-bromobenzoate (2) which was then transformed into 3-bromobenzohydrazide (3). The final step involved the cyclization of compound 3, producing its 1,2,4-triazole derivative (4). This intermediate was then coupled with different electrophiles, resulting in the formation of the final derivatives (7a-7c). Additionally, the characterization of these triazole-based compounds (7a, 7b, and 7c) were carried out using techniques such as IR, HNMR, and UV-visible spectroscopy to understand their structural and spectroscopic properties. The DFT study utilized M06/6-311G(d,p) functional to investigate geometrical parameters, HOMO-LUMO energies, natural bond orbital analyses, transition density matrix (TDM), density of states, and nonlinear optical (NLO) properties. The FMO analysis revealed that compound 7c exhibited the lowest band gap value (4.618 eV). Notably, compound 7c exhibited significant linear polarizability (4.195 >  × 10-23) and first and second hyperpolarizabilities (6.317 >  × 10-30, 4.314 × 10-35), signifying its potential for nonlinear optical applications. These NLO characteristics imply that each of our compounds, especially 7c, plays a crucial part in fabricating materials showing promising NLO properties for optoelectronic applications.

Synthesis and Evaluation of Imidazole Derivatives Bearing Imidazo[2,1-b] [1,3,4]thiadiazole Moiety as Antibacterial Agents

BACKGROUND

Drug-resistant infections kill hundreds of thousands of people globally every year. In previous work, we found that tri-methoxy- and pyridine-substituted imidazoles show strong antibacterial activities.

OBJECTIVE

The aim of this work was to investigate the antibacterial activities and bacterial resistances of imidazoles bearing an aromatic heterocyclic, alkoxy, or polycyclic moiety on the central ring.

METHODS

Three series of 2-cyclopropyl-5-(5-(6-methylpyridin-2-yl)-2-substituted-1H-imidazol-4- yl)-6-phenylimidazo[2,1-b][1,3,4]thiadiazoles (13a-e, 14a-d, and 15a-f) were synthesized and their antibacterial activity was evaluated. The structures were confirmed by their 1H NMR, 13C NMR, and HRMS spectra. All the synthesized compounds were screened against Gram-positive, Gramnegative, and multidrug-resistant bacterial strains.

RESULTS

More than half of the compounds showed moderate or strong antibacterial activity. Among them, compound 13e (MICs = 1-4 μg/mL) showed the strongest activity against Gram-positive and drug-resistant bacteria as well as high selectivity against Gram-negative bacteria. Furthermore, it showed no cytotoxicity against HepG2 cells, even at 100 μM, and no hemolysis at 20 μM.

CONCLUSION

These results indicate that compound 13e is excellent candicate for further study as a potential antibacterial agent.

Design, synthesis, evaluation and optimization of novel azole analogues as potent antifungal agents

In order to develop antifungal drugs, a series of novel azole analogues were designed and synthesized based on our previous work. Most of the target compounds had broad-spectrum antifungal activity, which showed excellent to moderate inhibitory activity against the tested strains, except A. fum 0504656. Among these, compounds B3, B7, B8, B11, B12 and E9 showed excellent activity against C. alb Y0109 and C. alb SC5314 (with the MIC80: 0.0156 ug/mL). In addition, compound B3 showed the best inhibitory activity against fluconazole-resistant strains C. alb 901 and C. alb 904, and had low toxicity against NIH/3T3 cells at the effective MIC range against fungi. Structure-activity relationship and docking studies of the derivatives suggest that the presence of the 2-fluoro-4-hydroxyphenyl and 1,2,3-triazole group enhance the antifungal activity of the compounds, which may be related to the interaction of the key groups with the amino acids surrounding the target enzyme.

Crystal structure and Hirshfeld-surface analysis of di-aqua-bis-(5-methyl-1H-1,2,4-triazole-3-carboxyl-ato)copper(II)

The title compound, [Cu(HL)2(H2O)2] or [Cu(C4H4N3O2)2(H2O)2], is a mononuclear octa-hedral CuII complex based on 5-methyl-1H-1,2,4-triazole-3-carb-oxy-lic acid (H2 L). [Cu(HL)2(H2O)2] was synthesized by reaction of H2 L with copper(II) nitrate hexa-hydrate (2:1 stoichiometric ratio) in water under ambient conditions to produce clear light-blue crystals. The central Cu atom exhibits an N2O4 coordination environment in an elongated octa-hedral geometry provided by two bidentate HL - anions in the equatorial plane and two water mol-ecules in the axial positions. Hirshfeld surface analysis revealed that the most important contributions to the surface contacts are from H⋯O/O⋯H (33.1%), H⋯H (29.5%) and H⋯N/N⋯H (19.3%) inter-actions.

Antifungal triazoles affect key non-target metabolic pathways in Solanum lycopersicum L. plants

Several 1,2,4-triazoles are widely used as systemic fungicides in agriculture because they inhibit fungal 14ɑ-demethylase. However, they can also act on many non-target plant enzymes, thereby affecting phytohormonal balance, free amino acid content, and adaptation to stress. In this study, tomato plants (Solanum lycopersicum L. var. 'Cherrola') were exposed to penconazole, tebuconazole, or their combination, either by foliar spraying or soil drenching, every week, as an ecotoxicological model. All triazole-exposed plants showed a higher content (1.7-8.8 ×) of total free amino acids than the control, especially free glutamine and asparagine were increased most likely in relation to the increase in active cytokinin metabolites 15 days after the first application. Conversely, the Trp content decreased in comparison with control (0.2-0.7 ×), suggesting depletion by auxin biosynthesis. Both triazole application methods slightly affected the antioxidant system (antioxidant enzyme activity, antioxidant capacity, and phenolic content) in tomato leaves. These results indicated that the tomato plants adapted to triazoles over time. Therefore, increasing the abscisic and chlorogenic acid content in triazole-exposed plants may promote resistance to abiotic stress.

New 2,4-dihydro-1H-1,2,4-triazole-3-selones and 3,3'-di(4H-1,2,4-triazolyl)diselenides. Synthesis, biological evaluation, and in silico studies as antibacterial and fungicidal agents

The reaction of aromatic ring-substituted isoselenocyanates with 2-thiopheacetic and 4-pyridinecarboxylic acid hydrazides yielded selenosemicarbazides which were further converted into previously unknown 1,2,4-triazole-3-selones and 3,3'-di(4H-1, 2,4-triazolyl)diselenides. The structures of the obtained compounds were studied by NMR spectroscopy, IR spectroscopy, and high-resolution mass spectroscopy (HR-MS). The bactericidal and fungicidal activity of some obtained compounds was evaluated in molecular modeling studies such as docking and simulation studies. The compound 3ba was reported as the most promising compound to show robust binding energy with different antibacterial and antifungal compounds. The compounds were observed in strong hydrophilic and hydrophobic interactions and remained in stable binding conformation with the receptor enzymes. Furthermore, the interatomic interaction energies were dominated by Van der Waals and electrostatic energies indicating the formation of stable complexes.

Synthesis and biological evaluation of ciprofloxacin - 1,2,3-triazole hybrids as antitumor, antibacterial, and antioxidant agents

Six novel ciprofloxacin-1,2,3-triazole hybrids (6a-f) were synthesized via click reaction, by reacting of methyl 1-cyclopropyl-6-fluoro-4-oxo-7-(4-(3-oxobutanoyl)piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylate (5) with various aryl azides (9a-f). The new compounds were characterized using High-Resolution Mass Spectrometry (HRMS), 1H NMR, 13C NMR, and elemental analysis. Compounds (6a-f) screened for their in vitro anticancer activity against three cell lines, namely, non-small cell lung cancer (A549), glioblastoma (U-87 MG), and breast cancer (MCF7). Hybrids 6a and 6b exhibited remarkable anti-proliferative activity against all three cell-lines. IC50 values of 6b for all cancer cell lines were significantly lower comparing to the standard reference compound IC50. The IC50 of 6b for the normal cell (HDF) line was significantly higher than the reported for cisplatin [IC50 = 170.7 ± 8.1 μM/ml (HDF), (p ≤ 0.001)], indicating less toxicity towards normal cells and thereby has a better therapeutic index, with a selectivity index of 142.3 for U87 cell line. Compounds 6e, 6d, and 6f displayed significant cytotoxic activity against only U-87 and MCF-7 cancer cell lines, compared to normal cells (HDF). Compound 6f [IC50 = 7.9 ± 2.3 μM/ml (U-87) and 10.6 ± 3 μM/ml (MCF-7)] was more potent than cisplatin [IC50 = 28.3 ± 5.3 μM/ml (U-87) and 26.9 ± 4.7 μM/ml (MCF-7)] in displaying anti-proliferative effect against U-87 and MCF-7 cells, with less cytotoxic to normal cells [IC50 = 141.7 ± 4.1] than cisplatin [IC50 = 40.9 ± 5.4]. Moreover, they were tested for their antioxidant activity in DPPH and ABTS assays and antibacterial activity.

Synthesis and Antibacterial Activity of Novel Triazolo[4,3-a]pyrazine Derivatives

Infectious diseases pose a major challenge to human health, and there is an urgent need to develop new antimicrobial agents with excellent antibacterial activity. A series of novel triazolo[4,3-a]pyrazine derivatives were synthesized and their structures were characterized using various techniques, such as melting point, 1H and 13C nuclear magnetic resonance spectroscopy, mass spectrometry, and elemental analysis. All the synthesized compounds were evaluated for in vitro antibacterial activity using the microbroth dilution method. Among all the tested compounds, some showed moderate to good antibacterial activities against both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli strains. In particular, compound 2e exhibited superior antibacterial activities (MICs: 32 μg/mL against Staphylococcus aureus and 16 μg/mL against Escherichia coli), which was comparable to the first-line antibacterial agent ampicillin. In addition, the structure-activity relationship of the triazolo[4,3-a]pyrazine derivatives was preliminarily investigated.

Recent advances in triazoles as tyrosinase inhibitors

The tyrosinase enzyme, which is widely found in microorganisms, animals and plants, has a significant position in melanogenesis, plays an important role in undesirable browning of fruits and vegetables, antibiotic resistance, skin pigment formation, sclerotization of cuticle, neurodegeneration, etc. Therefore, with the wide potential application fields of tyrosinase in food, agriculture, cosmetics and pharmaceutical industries, which has become the target enzyme for the development of therapeutic agents such as antibrowning, anticancer, antibacterial, skin whitening, insecticides, etc., a large number of synthetic tyrosinase inhibitors have been widely reported in recent years. The triazole ring, which has a broad spectrum of biological action, is of increasing interest in the synthesis of new tyrosinase inhibitors. In this review, tyrosinase inhibition effects, structure-activity relationships, enzyme inhibition kinetics and mechanisms of action of 1,2,3- or 1,2,4-triazole derivatives were investigated. The data gathered is anticipated to supply rational guidance and an influential strategy for the development of novel, potent and safe tyrosinase inhibitors for better practical application in the future.

Recent advances in 1,2,3- and 1,2,4-triazole hybrids as antimicrobials and their SAR: A critical review

With the widespread use and sometimes even abuse of antibiotics, the problem of bacterial resistance to antibiotics has become very serious, and it is posing a great threat to global health. Therefore, development of new antibiotics is imperative. Triazoles are five-membered, nitrogen-containing aromatic heterocyclic scaffolds, with two isomeric forms, i.e. 1,2,3-triazole and 1,2,4-triazole. Triazole-containing compounds have a wide range of biological activities such as antibacterial, antifungal, anticancer, antioxidant, antitubercular, antimalarial, anti-HIV, anticonvulsant, anti-inflammatory, antiulcer, analgesic, and etc. The bioactivities and the diversity of triazole-containing drugs have attracted wide interest in these heterocycles. Various antibiotic triazole hybrids have been developed, and most of which have shown potent antimicrobial activities. In this review, we summarized the recent advances in triazole hybrids as potential antibacterial agents and their structure-activity relationships (SARs). The information gained through SAR studies will provide further insights into the development of new triazole antimicrobials.

Synthesis, Anticancer Activity, and In Silico Studies of 5-(3-Bromophenyl)-N-aryl-4H-1,2,4-triazol-3-amine Analogs

In the current study, we described the synthesis of ten new 5-(3-Bromophenyl)-N-aryl-4H-1,2,4-triazol-3-amine analogs (4a-j), as well as their characterization, anticancer activity, molecular docking studies, ADME, and toxicity prediction. The title compounds (4a-j) were prepared in three steps, starting from substituted anilines in a satisfactory yield, followed by their characterization via spectroscopic techniques. The National Cancer Institute (NCI US) protocol was followed to test the compounds' (4a-j) anticancer activity against nine panels of 58 cancer cell lines at a concentration of 10-5 M, and growth percent (GP) as well as percent growth inhibition (PGI) were calculated. Some of the compounds demonstrated significant anticancer activity against a few cancer cell lines. The CNS cancer cell line SNB-75, which showed a PGI of 41.25 percent, was discovered to be the most sensitive cancer cell line to the tested compound 4e. The mean GP of compound 4i was found to be the most promising among the series of compounds. The five cancer cell lines that were found to be the most susceptible to compound 4i were SNB-75, UO-31, CCRF-CEM, EKVX, and OVCAR-5; these five cell lines showed PGIs of 38.94, 30.14, 26.92, 26.61, and 23.12 percent, respectively, at 10-5 M. The inhibition of tubulin is one of the primary molecular targets of many anticancer agents; hence, the compounds (4a-j) were further subjected to molecular docking studies looking at the tubulin-combretastatin A-4 binding site (PDB ID: 5LYJ) of tubulin. The binding affinities were found to be efficient, ranging from -6.502 to -8.341 kcal/mol, with two major electrostatic interactions observed: H-bond and halogen bond. Ligand 4i had a binding affinity of -8.149 kcal/mol with the tubulin-combretastatin A-4 binding site and displayed a H-bond interaction with the residue Asn258. The ADME and toxicity prediction studies for each compound were carried out using SwissADME and ProTox-II software. None of the compounds' ADME predictions showed that they violated Lipinski's rule of five. All of the compounds were also predicted to have LD50 values between 440 and 500 mg/kg, putting them all in class IV toxicity, according to the toxicity prediction. The current discovery could potentially open up the opportunity for further developments in cancer.

Evaluation of the Antibacterial Effect of Aurone-Derived Triazoles on Staphylococcus aureus

Infections caused by antibiotic-resistant bacteria continue to pose a significant public health threat despite their overall decreasing numbers in the last two decades. One group of compounds fundamental to the search for new agents is low-cost natural products. In this study, we explored a group of newly synthesized novel aurone-derived triazole compounds to identify those with pharmaceutical potential as inhibitors of antibiotic-resistant Staphylococcus aureus. Using the broth microdilution method, antibacterial activities against methicillin-resistant S. aureus ATCC 43300 (MRSA) and methicillin-sensitive S. aureus ATCC 29213 (MSSA) were identified for four aurone-derived triazole compounds, AT106, AT116, AT125, and AT137, using the half-maximal inhibitory concentrations for the bacteria (IC50) and mammalian cell lines (CC50). Compounds AT125 and AT137 were identified to have pharmaceutical potential as the IC50 values against MRSA were 5.412 µM and 3.870 µM, whereas the CC50 values measured on HepG2 cells were 50.57 µM and 39.81 µM, respectively, resulting in selectivity indexes (SI) > 10. Compounds AT106 and AT116 were also selected for further study. IC50 values for these compounds were 5.439 µM and 3.178 µM, and the CC50 values were 60.33 µM and 50.87 µM, respectively; however, SI values > 10 were for MSSA only. Furthermore, none of the selected compounds showed significant hemolytic activity for human erythrocytes. We also tested the four compounds against S. aureus biofilms. Although AT116 and AT125 successfully disrupted MSSA biofilms, there was no measurable potency against MRSA biofilms. Checkerboard antibiotic assays to identify inhibitory mechanisms for these compounds indicated activity against bacterial cell membranes and cell walls, supporting the pharmaceutical potential for aurone-derived triazoles against antibiotic-resistant bacteria. Examining structure-activity relationships between the four compounds in this study and other aurone-derived triazoles in our library suggest that substitution with a halogen on either the salicyl ring or triazole aryl group along with triazoles having nitrile groups improves anti-Staphylococcal activity with the location of the functionality being very important.

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.

CuFe2O4@SiO2@L-arginine@Cu(I) as a new magnetically retrievable heterogeneous nanocatalyst with high efficiency for 1,4-disubstituted 1,2,3-triazoles synthesis

A novel magnetic heterogeneous catalyst was synthesized through the immobilization of copper ions onto the l-arginine functionalized CuFe₂O₄@SiO₂. The prepared catalyst was characterized by Fourier Transform Infrared (FT-IR), X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM), and Energy Dispersive X-Ray spectroscopy (EDX). The resulting catalyst was used in the ultrasonic-assisted synthesis of 1,2,3-triazoles via a one-pot three-component reaction of alkynes, alkyl halides, and sodium azides under green conditions within a short time. The catalyst reusability was investigated after five cycles and no significant loss of activity was observed.

Hydrazone-Tethered 5-(Pyridin-4-yl)-4H-1,2,4-triazole-3-thiol Hybrids: Synthesis, Characterisation, in silico ADME Studies, and in vitro Antimycobacterial Evaluation and Cytotoxicity

Compounds containing arylpyrrole-, 1,2,4-triazole- and hydrazone structural frameworks have been widely studied and demonstrated to exhibit a wide range of pharmacological properties. Herein, an exploratory series of new 1,2,4-triazole derivatives designed by amalgamation of arylpyrrole and 1,2,4-triazole structural units via a hydrazone linkage is reported. The synthesised compounds were tested in vitro for their potential activity against Mycobacterium tuberculosis (MTB) H₃₇ Rv strain. The most promising compound 13 - the derivative without the benzene ring appended to the pyrrole unit displayed acceptable activity (MIC₉₀ =3.99 μM) against MTB H₃₇ Rv, while other compounds from the series exhibited modest to weak antimycobacterial activity with MIC₉₀ values in the range between 7.0 and >125 μM. Furthermore, in silico results, predicated using the SwissADME web tool, show that the prepared compounds display desirable ADME profile with parameters within acceptable range.

An in silico investigation of 1,2,4-triazole derivatives as potential antioxidant agents using molecular docking, MD simulations, MM-PBSA free energy calculations and ADME predictions

In this study, we’ve performed computable studies of previously synthesized 1,2,4-triazole derivatives by virtual screening due to antioxidant activity. Six enzymes responsible for regulating oxidative stress were selected as key targets. One hundred and twelve compounds were subjected to semi-flexible molecular docking, which resulted in the selection of 23 substances based on binding energy for further ADME analysis. In addition, molecular dynamics studies of complexes with the best docking scores, reference complexes and apo-proteins were described in detail here. The results of 100 ns modeling (RMSD, RMSF, SASA, Rg, PCA) indicate great stability during the formation of complexes with our two potential compounds, as well as favorable binding energy, which was determined theoretically by means of the MM/PBSA method, thereby increase the likelihood of their acting as promising inhibitors of selected enzymes.

An Overview of 1,2,3-triazole-Containing Hybrids and Their Potential Anticholinesterase Activities

Acetylcholine (ACh) neurotransmitter of the cholinergic system in the brain is involved in learning, memory, stress responses, and cognitive functioning. It is hydrolyzed into choline and acetic acid by two key cholinesterase enzymes, viz., acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). A loss or degeneration of cholinergic neurons that leads to a reduction in ACh levels is considered a significant contributing factor in the development of neurodegenerative diseases (NDs) such as Alzheimer's disease (AD). Numerous studies have shown that cholinesterase inhibitors can raise the level of ACh and, therefore, enhance people's quality of life, and, at the very least, it can temporarily lessen the symptoms of NDs. 1,2,3-triazole, a five-membered heterocyclic ring, is a privileged moiety, that is, a central scaffold, and is capable of interacting with a variety of receptors and enzymes to exhibit a broad range of important biological activities. Recently, it has been clubbed with other pharmacophoric fragments/molecules in hope of obtaining potent and selective AChE and/or BuChE inhibitors. The present updated review succinctly summarizes the different synthetic strategies used to synthesize the 1,2,3-triazole moiety. It also highlights the anticholinesterase potential of various 1,2,3-triazole di/trihybrids reported in the past seven years (2015-2022), including a rationale for hybridization and with an emphasis on their structural features for the development and optimization of cholinesterase inhibitors to treat NDs.

Coumarin Triazoles as Potential Antimicrobial Agents

Currently, in hospitals and community health centers, microbial infections are highly common diseases and are a leading cause of death worldwide. Antibiotics are generally used to fight microbial infections; however, because of the abuse of antibiotics, microbes have become increasingly more resistant to most of them. Therefore, medicinal chemists are constantly searching for new or improved alternatives to combat microbial infections. Coumarin triazole derivatives displayed a variety of therapeutic applications, such as antimicrobial, antioxidant, and anticancer activities. This review summarizes the advances of coumarin triazole derivatives as potential antimicrobial agents covering articles published from 2006 to 2022.

A novel and efficient one-pot strategy for the synthesis of 1,2,4-triazoles: access to synthesis of penipanoid A and its analogues

We developed a novel one-pot strategy for synthesizing biologically important 1,2,4-triazole motifs from easily accessible 4-hydroxy phenylacetic acid, formamidine hydrochloride and hydrazine derivatives under mild conditions. This strategy enabled us to synthesize the natural penipanoid A and its analogues in one step.

Design, synthesis and screening of indole acetic acid-based tri-azo moieties as antioxidants, anti-microbial and cytotoxic agents

Multidrug resistance and infectious disease have enormous spread despite drug discovery and development advancements. 1, 2, 4 -triazoles have been extensively studied, playing an imperative role in many pathologic conditions. A series of Schiff base triazoles; derived from Indole -3- acetic acid with substituted Benzaldehydes (5a-5g) were designed, synthesized, and evaluated through various Spectroanalytical techniques. SwissADME was used to assess physicochemical properties and pharmacokinetic drug-likeliness behavior. (5a-5g) were evaluated for their varied biological potential through antioxidant, antimicrobial, enzyme inhibition, and cytotoxic evaluation. Schiff bases express drug-like nature as they follow Lipinski's rule of five. 5b showed good antioxidant potential in total antioxidant capacity (TAC) and total reducing power (TRP) assays and was most active in the library in % free radical scavenging assay (%FRSA), showing 32% inhibition at 50 μg/mL concentration. Compounds showed antibacterial activity against various tested strains. 5e and 5f showed a minimum inhibitory concentration (MIC) value of 3.12 μg/mL for P.aeruginosa and K.pneumoniae, respectively. In the antifungal assay, only 5e inhibited one strain with a zone of inhibition >6 mm. These synthetic molecules possess good cytotoxic potential in the Brine Shrimp Lethality screening; 5c, 5d, and 5f exhibited LC_{50 =}5.7 μg/mL. In the protein kinase inhibition assay, 5a, 5b, and 5g demonstrated inhibitory potential, showcasing the zone of inhibition as 7.5-10.5 mm for the bald one and 6-7.5 for the clear zone. These findings suggest that the compounds have antibacterial and cytotoxic potential, and there is a chance for further research and development in this area.

Regioselective Synthesis of 5-Trifluoromethyl 1,2,4-Triazoles via [3 + 2]-Cycloaddition of Nitrile Imines with CF3CN

We herein describe a general approach to 5-trifluoromethyl 1,2,4-triazoles via the [3 + 2]-cycloaddition of nitrile imines generated in situ from hydrazonyl chloride with CF₃CN, utilizing 2,2,2-trifluoroacetaldehyde O-(aryl)oxime as the precursor of trifluoroacetonitrile. Various functional groups, including alkyl-substituted hydrazonyl chloride, were tolerated during cycloaddition. Furthermore, the gram-scale synthesis and common downstream transformations proved the potential synthetic relevance of this developed methodology.

Structural and Energetic Properties of Weak Noncovalent Interactions in Two Closely Related 3,6-Disubstituted-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole Derivatives: In Vitro Cyclooxygenase Activity, Crystallography, and Computational Investigations

Two 3,6-disubstituted-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole derivatives, namely, 3-(adamantan-1-yl)-6-(2-chloro-6-fluorophenyl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole 1 and 6-(2-chloro-6-fluorophenyl)-3-phenyl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole 2, were prepared, and the detailed analysis of the weak intermolecular interactions responsible for the supramolecular self-assembly was performed using X-ray diffraction and theoretical tools. Analyses of Hirshfeld surface and 2D fingerprint plot demonstrated the effect of adamant-1-yl/phenyl moieties on intermolecular interactions in solid-state structures. The effect of these substituents on H···H/Cl/N contacts was more specific. The CLP-PIXEL and density functional theory methods provide information on the energetics of molecular dimers observed in these compounds. The crystal structure of compound 1 stabilizes with a variety of weak intermolecular interactions, including C–H···N, C–H···π, and C–H···Cl hydrogen bonds, a directional C–S···π chalcogen bond, and unconventional short F···C/N contacts. The crystal structure of compound 2 is stabilized by π-stacking interactions, C–H···N, C–H···π, and C–H···Cl hydrogen bonds, and highly directional attractive σ–hole interactions such as the C–Cl···N halogen bond and the C–S···N chalcogen bond. In addition, S(lp)···C(π) and short N···N contacts play a supportive role in the stabilization of certain molecular dimers. The final supramolecular architectures resulting from the combination of different intermolecular interactions are observed in both the crystal packing. The molecular electrostatic potential map reveals complementary electrostatic potentials of the interacting atoms. The quantum theory of atoms in molecules approach was used to delineate the nature and strength of different intermolecular interactions present in different dimers of compounds 1 and 2. The in vitro experiments suggest that both compounds showed selectivity against COX-2 targets rather than COX-1. Molecular docking analysis showed the binding pose of the compounds at the active sites of COX-1/2 enzymes.

Identification of Small Molecule Inhibitors against Mycobacteria in Activated Macrophages

Mycobacterial pathogens are intrinsically resistant to many available antibiotics, making treatment extremely challenging, especially in immunocompromised individuals and patients with underlying and chronic lung conditions. Even with lengthy therapy and the use of a combination of antibiotics, clinical success for non-tuberculous mycobacteria (NTM) is achieved in fewer than half of the cases. The need for novel antibiotics that are effective against NTM is urgent. To identify such new compounds, a whole cell high-throughput screen (HTS) was performed in this study. Compounds from the Chembridge DIVERSet library were tested for their ability to inhibit intracellular survival of M. avium subsp. hominissuis (MAH) expressing dtTomato protein, using fluorescence as a readout. Fifty-eight compounds were identified to significantly inhibit fluorescent readings of MAH. In subsequent assays, it was found that treatment of MAH-infected THP-1 macrophages with 27 of 58 hit compounds led to a significant reduction in intracellular viable bacteria, while 19 compounds decreased M. abscessus subsp. abscessus (Mab) survival rates within phagocytic cells. In addition, the hit compounds were tested in M. tuberculosis H37Ra (Mtb) and 14 compounds were found to exhibit activity in activated THP-1 cells. While the majority of compounds displayed inhibitory activity against both replicating (extracellular) and non-replicating (intracellular) forms of bacteria, a set of compounds appeared to be effective exclusively against intracellular bacteria. The efficacy of these compounds was examined in combination with current antibiotics and survival of both NTM and Mtb were evaluated within phagocytic cells. In time-kill dynamic studies, it was found that co-treatment promoted increased bacterial clearance when compared with the antibiotic or compound group alone. This study describes promising anti-NTM and anti-Mtb compounds with potential novel mechanisms of action that target intracellular bacteria in activated macrophages.

A Facile One-Pot Synthesis of New Poly Functionalized Pyrrolotriazoles via a Regioselective Multicomponent Cyclisation and Suzuki–Miyaura Coupling Reactions

The first access to N-1, N-4 disubstituted pyrrolo[2,3-d][1,2,3]triazoles is reported. The series were generated using a “one-pot” MCR, leading to a single regioisomer of the attempted heteroaromatic skeleton in good yields. Next, the functionalization of C-5 and C-6 positions was investigated. (Het)aryl groups were introduced at the C-5 and C-6 positions of the pyrrolo[2,3-d][1,2,3]triazoles using regioselective electrophilic brominations followed by Suzuki–Miyaura cross coupling reactions. Palladium-catalyzed cross-coupling conditions were optimized and a representative library of various boronic acids was employed to establish the scope and limitations of the method.

Pd-Catalyzed regio- and stereoselective allylic substitution of vinylethylene carbonates with 1,2,4-triazoles

N ¹-Substituted 1,2,4-triazoles are ubiquitous skeletons in medicinal agents, agrochemicals, and organic materials. Herein, an efficient and practical method for the synthesis of N¹-allylated 1,2,4-triazoles via Pd-catalyzed allylic substitution of vinylethylene carbonates (VECs) with 1,2,4-triazoles has been developed. By using a catalyst generated in situ from Pd₂(dba)₃·CHCl₃ and DPPE under mild conditions, the process allows rapid access to N¹-allylated 1,2,4-triazoles bearing diverse functionalities in high yields with excellent N¹-selectivities, linear-selectivities, and Z-stereoselectivities.

Chemical Composition and Biological Evaluation of Typha domingensis Pers. to Ameliorate Health Pathologies: In Vitro and In Silico Approaches

Human diseases are becoming more prevalent, necessitating the development of modalities to overcome the challenges of treating various disorders. In the current research, we analyzed the biomedicinal role of Typha domingensis which is an important medicinal plant. The species is traditionally used in the treatment of neurological disorders and skin malignancies. The chloroform (CFTD) and n-butanol fractions of T. domingensis (BFTD) were subjected to chemical profiling through the determination of total polyphenolic contents and GC-MS analysis. The oral toxicity test was applied to investigate the toxicity of the extracts. Antioxidant capacity was analyzed by four in vitro methods: DPPH, ABTS, FRAP, and CUPRAC. The pharmacological potential was evaluated through clinically significant enzyme inhibition assays, thrombolytic, and antimicrobial activities. In silico molecular docking approach was applied to confirm the role of T. domingensis against the enzymes. The polyphenolic quantification revealed that the BFTD was comparatively rich in total phenolic and flavonoid contents (97.14 milligrams gallic acid equivalent (mg GAE/g) and 362.5 milligrams quercetin equivalent per gram of dry extract (mg QE/g DE), respectively), as compared to the CFTD. The GC-MS analysis of the CFTD and BFTD resulted in the tentative identification of 67 and 29 compounds, respectively, with the major components of fatty acids and essential oil. The oral toxicity test revealed the safety and biocompatibility of CFTD and BFTD. Both the fractions showed promising antioxidant activity. Tyrosinase was found as the major enzyme inhibited by BFTD (78.67%) and CFTD (68.09%), whereas the standard kojic acid showed 85.58% inhibition. The inhibition results of acetylcholinesterase and butyrylcholinesterase by BFTD (71.65 and 60.79%, respectively) are higher than CFTD. Both the fractions were found active against various strains of bacteria. Furthermore, the molecular docking studies of the compounds showed a good docking score against all the docked enzymes among which deoxycaesaldekarin C was found with the highest binding affinities in comparison to the standard. The current study suggests that T. domingensis is nontoxic and can be a potential source of phytoconstituents with promising pharmacological potential.

Green phytoextracts as natural photosensitizers in LED-based photodynamic disinfection of multidrug-resistant bacteria in wastewater effluent

The photodynamic treatment (PDT) process is a promising technology to control emerging pollutants and antimicrobial resistance problems in the water environment. The reactive oxygen species (ROS) produced when natural and nontoxic photosensitizers (PS) are exposed to light are the key functional components of the PDT process that can effectively achieve microbial inactivation with minimal negative impact. This study examined the application of green phytoextracts from two plants, Chamaecyparis obtusa and Moringa oleifera, as natural photosensitizers for the white light-emitting diode (LED) based photodynamic disinfection of multidrug-resistant (MDR) and total coliforms (TC) from secondary effluent in full-scale municipal wastewater treatment plants. Gas chromatography-mass spectrometry and Fourier transform infrared spectroscopy showed that the phytoextracts contained 57 compounds, particularly aromatic and phenolic hydroxyl compounds. The phytoextracts showed an excellent activity as a PS compared to the intrinsic antibacterial effect. Under a light intensity of 17 mW/cm², the complete inactivation (6.55 Log CFU/mL) was observed at an irradiation time of 100 min for Escherichia coli ART-2 and 80 min for Staphylococcus aureus, meaning that E. coli was resistant. The light intensity was an important factor influencing photodynamic disinfection. For the complete disinfection of TC satisfying the water reclamation regulation, the irradiation time requirement was 20 min under a light intensity of 80 mW/cm². During the photodynamic reaction, a significant amount of ROS was generated from the phytoextracts as the light irradiation time was increased. The major ROS was singlet oxygen (¹O₂, Type II) during the initial 40 min of reaction time and hydroxyl radical (•OH, Type I) after 40 min until complete inactivation.

Synthesis and Antimicrobial Activity of 1,3,4-Oxadiazoline, 1,3-Thiazolidine, and 1,2,4-Triazoline Double-Tailed Acyclo C-Nucleosides

The condensation products of terphthaloyl bishydrazide with two equivalents of various monosaccharide aldoses were found to have a bis(sugarhydrazone) form or bis-glycosylhydrazide structure or coexist in tautomeric equilibrium depending on the sugar configuration. The condensation products were substantially utilized as 3-acetyl-1,3,4-oxadiazoline, 1,3-thiazolidine, and 4-amino-1,2,4-triazoline double-tailed acyclo C-nucleosides synthons. The preliminary antimicrobial activities of representative examples of the prepared compounds were evaluated.

Novel 1, 2, 4-Triazoles as Antifungal Agents

The development of innovative antifungal agents is essential. Some fungicidal agents are no longer effective due to resistance development, various side effects, and high toxicity. Therefore, the synthesis and development of some new antifungal agents are necessary. 1,2,4-Triazole is one of the most essential pharmacophore systems between five-membered heterocycles. The structure-activity relationship (SAR) of this nitrogen-containing heterocyclic compound showed potential antifungal activity. The 1,2,4-triazole core is present as the nucleus in a variety of antifungal drug categories. The most potent and broad activity of triazoles have confirmed them as pharmacologically significant moieties. The goal of this review is to highlight recent developments in the synthesis and SAR study of 1,2,4-triazole as a potential fungicidal compound. In this study, we provide the results of a biological activity evaluation using various structures and figures. Literature investigation showed that 1, 2, 4-triazole derivatives reveal the extensive span of antifungal activity. This review will assist researchers in the development of new potential antifungal drug candidates with high effectiveness and selectivity.