Novel 1,2,4-triazoles as selective carbonic anhydrase inhibitors showing ancillary anticathepsin B activity

Background: Exploration of the multi-target approach considering both human carbonic anhydrase (hCA) IX and XII and cathepsin B is a promising strategy to target cancer. Methodology & Results: 22 novel 1,2,4-triazole derivatives were synthesized and evaluated for their inhibition efficacy against hCA I, II, IX, XII isoforms and cathepsin B. The compounds demonstrated effective inhibition against hCA IX and/or XII isoforms with considerable selectivity over off-target hCA I/II. All compounds presented significant anticathepsin B activities at a low concentration of 10-7 M and in vitro results were also supported by the molecular modeling studies. Conclusion: Insights of present study can be utilized in the rational design of effective and selective hCA IX and XII inhibitors capable of inhibiting cathepsin B.

Discovery of Potential Rosin-Based Triazole Antifungal Candidates to Control Valsa mali for Sustainable Crop Protection

To investigate the potential application value of dehydroabietic acid, 27 novel dehydroabietyl-1,2,4-triazole-5-thioether-based derivatives were designed and characterized by IR, 1H NMR, 13C NMR, and LC-MS. Their antifungal activities were evaluated against five plant fungi, namely, Valsa mali, Colletotrichum orbiculare, Fusarium graminearum, Sclerotinia sclerotiorum, and Gaeumannomyces graminis; the results showed that compound 5h-1 (Co. 5h-1) exhibited a considerable inhibitory effect against V. mali. Moreover, in vivo experiments indicated that Co. 5h-1 had a certain protective effect on apple branches. The preliminary structure-activity relationship analysis suggested that the electron-withdrawing group on the benzyl group was significantly better than that of other substituent derivatives. Through electron microscopy analysis, it was found that Co. 5h-1 hindered the growth of mycelia, damaged their cell structure, and caused the large accumulation of reactive oxygen species (ROS). Preliminary research on the mode of action indicated that Co. 5h-1 could affect the activity of CAT by increasing the α-helix (0.790%), decreasing the β-sheet (0.170%), which led to the accumulation of ROS. In addition, Co. 5h-1 also affected the activity of CYP51, hindered the biosynthesis of ergosterol, and increased cell membrane permeability. Overall, this above research proposed that Co. 5h-1 can be a novel leading structure for development of a fungicide agent.

Design and Synthesis of Novel Phthalide Derivatives containing 1,3,4-Oxadiazole/1,2,4-Triazole Units as Potential Antifungal Agents

Four series of novel 1,3,4-oxadiazole/1,2,4-triazole hybrids of phthalide derivatives were designed and synthesized to search for novel potential antifungal agents. Preliminary antifungal activity assay results showed that compounds 4 a, 4 b, 4 m, 5 b, 5 f, 5 h, and 7 h exhibited moderate to excellent inhibitory activity against some phytopathogenic fungi. Among them, compound 5 b displayed the most outstanding antifungal effects against V. mali and S. sclerotiorum, with the EC50 mean of 3.96 μg/mL and 5.60 μg/mL, respectively, which was superior to those of commercial fungicides hymexazol and chlorothalonil. Furthermore, compound 5 b could completely suppress the spore germination of V. mali at a concentration of 10 μg/mL. Finally, molecular docking revealed that the potential target for the antifungal activity of compound 5 b was succinate dehydrogenase (SDH). This research provides novel candidate compounds for the prevention of phytopathogenic fungi.

Synthesis, crystal structure and Hirshfeld surface analysis of 2-({5-[(naphthalen-1-yl)meth-yl]-4-phenyl-4H-1,2,4-triazol-3-yl}sulfan-yl)-1-(4-nitro-phen-yl)ethanone

The title compound, C27H20N4O3S, crystallizes in the monoclinic system, space group P21/n, with Z = 4. The global shape of the mol-ecule is determined by the orientation of the substituents on the central 4H-1,2,4-triazole ring. The nitro-phenyl ring, phenyl ring, and naphthalene ring system are oriented at dihedral angles of 82.95 (17), 77.14 (18) and 89.46 (15)°, respectively, with respect to the triazole ring. The crystal packing features chain formation in the b-axis direction by S⋯O inter-actions. A Hirshfeld surface analysis indicates that the highest contributions to surface contacts arise from contacts in which H atoms are involved.

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.

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.

Triazole hybrid compounds: A new frontier in malaria treatment

Reviewing the advancements in malaria treatment, the emergence of triazole hybrid compounds stands out as a groundbreaking development. Combining the advantages of triazole and other moieties, these hybrid compounds offer a new frontier in the battle against malaria. Their potential as effective antimalarial agents has captured the attention of researchers and holds promise for overcoming the challenges posed by drug-resistant malaria strains. We focused on their broad spectrum of antimalarial activity of diverse hybridized 1,2,3-triazoles and 1,2,4-triazoles, structure-activity relationship (SAR), drug-likeness, bioavailability and pharmacokinetic properties reported since 2018 targeting multiple stages of the Plasmodium life cycle. This versatility makes them highly effective against both drug-sensitive and drug-resistant strains of P. falciparum, making them invaluable tools in regions where resistance is prevalent. The synergistic effects of combining the triazole moiety with other pharmacophores have resulted in even greater antimalarial potency. This approach has the potential to circumvent existing resistance mechanisms and provide a more sustainable solution to malaria treatment. While triazole hybrid compounds show great promise, further research and clinical trials are warranted to fully evaluate their safety, efficacy and long-term effects. As research progresses, these compounds can potentially revolutionize the field and contribute to global efforts to eradicate malaria, ultimately saving countless lives worldwide.

Novel 1,2,4-Triazole- and Tetrazole-Containing 4H-Thiopyrano[2,3-b]quinolines: Synthesis Based on the Thio-Michael/aza-Morita-Baylis-Hillman Tandem Reaction and Investigation of Antiviral Activity

A novel method for synthesizing 1,2,4-triazole- and tetrazole-containing 4H-thiopyrano[2,3-b]quinolines using a new combination of the thio-Michael and aza-Morita-Baylis-Hillman reactions was developed. Target compounds were evaluated for their cytotoxicities and antiviral activities against influenza A/Puerto Rico/8/34 virus in MDCK cells. The compounds showed low toxicity and some exhibited moderate antiviral activity. Molecular docking identified the M2 channel and polymerase basic protein 2 as potential targets. We observed that the antiviral activity of thiopyrano[2,3-b]quinolines is notably affected by both the nature and position of the substituent within the tetrazole ring, as well as the substituent within the benzene moiety of quinoline. These findings contribute to the further search for new antiviral agents against influenza A viruses among derivatives of thiopyrano[2,3-b]quinoline.

Synthesis and Characterization of Proton-Conducting Composites Prepared by Introducing Imidazole or 1,2,4-Triazole into AlPO-5 and SAPO-5 Molecular Sieves

The present work concerns proton-conducting composites obtained by replacing the water molecules present in aluminophosphate and silicoaluminophosphate AFI-type molecular sieves (AlPO-5 and SAPO-5) with azole molecules (imidazole or 1,2,4-triazole). Both the introduction of azoles and the generation of Brønsted acid centers by isomorphous substitution in aluminophosphate materials were aimed at improving the proton conductivity of the materials and its stability. In the presented study, AlPO-5 and several SAPO-5 materials differing in silicon content were synthesized. The obtained porous matrices were studied using PXRD, low-temperature nitrogen sorption, TPD-NH3, FTIR, and SEM. The proton conductivity of composites was measured using impedance spectroscopy. The results show that the increase in silicon content of the porous matrices is accompanied by an increase in their acidity. However, this does not translate into an increase in the conductivity of the azole composites. Triazole composites show lower conductivity and significantly higher activation energies than imidazole composites; however, most triazole composites show much higher stability. The different conductivity values for imidazole and triazole composites may be due to differences in chemical properties of the azoles.

New 1,2,3-Triazole/1,2,4-triazole Hybrids as Aromatase Inhibitors: Design, Synthesis, and Apoptotic Antiproliferative Activity

A novel series of 1,2,3-triazole/1,2,4-triazole hybrids 5a, 5b, and 6a-i was designed and synthesized as antiproliferative agents targeting aromatase enzymes. The antiproliferative activity of the new hybrids against four cancer cells was studied using Erlotinib as a control. Compounds 6a and 6b demonstrated the highest antiproliferative activity among these hybrids, with GI50 values of 40 nM and 35 nM, respectively. Compound 6b was the most potent derivative, with a GI50 of 35 nM, comparable to Erlotinib's GI50 of 33 nM. Compound 6b inhibited all cancer cell lines with comparable efficacy to Erlotinib. Compounds 5a, 5b, and 6a-i were tested for inhibitory action against aromatase as a potential target for their antiproliferative activity. Results revealed that compounds 6a and 6b were the most potent aromatase inhibitors, with IC50 values of 0.12 ± 0.01 µM and 0.09 ± 0.01 µM, respectively, being more potent than the reference Ketoconazole (IC50 = 2.6 ± 0.20 µM) but less potent than Letrozole (IC50 = 0.002 ± 0.0002). These findings indicated that compounds 6a and 6b had significant aromatase inhibitory action and are potential antiproliferative candidates. The findings were further linked to molecular docking investigations, which gave models of strong interactions with the aromatase domain for inhibitors with high binding scores.

New Schiff bases derived from dimethylpyridine-1,2,4-triazole hybrid as cytotoxic agents targeting gastrointestinal cancers: Design, synthesis, biological evaluation and molecular docking studies

In this research, a series of novel hybrid structures of dimethylpyridine-1,2,4-triazole Schiff bases were designed, synthesized, and evaluated for their in vitro cytotoxic potency on several human gastrointestinal cancer cells (EPG, Caco-2, LoVo, LoVo/Dx, HT29) and normal colonic epithelial cells (CCD 841 CoN). Schiff base 4h was the most potent compound against gastric EPG cancer cells (CC50 = 12.10 ± 3.10 μM), being 9- and 21-fold more cytotoxic than 5-FU and cisplatin, respectively. Moreover, it was not toxic to normal cells. Regarding the cytotoxicity against colorectal cancer cells, compounds 4d and 4l exhibited good activity against HT29 cells (CC50 = 52.80 ± 2.80 μM and 61.40 ± 10.70 μM, respectively), and were comparable to or more potent than cisplatin and 5-FU. Also, they were less toxic to normal cells with a higher selectivity index (SI, CCD 841 CoN/HT29 = 4.20 and 2.85, respectively) than reference drugs (SI, CCD 841 CoN/HT29 < 1). Selected Schiff bases were subjected to the P-glycoprotein inhibition assay. Schiff bases 4d, 4e, and 4l influenced P-gp efflux function, significantly increasing the accumulation of rhodamine 123 in colon cancer cell lines. Further mechanistic studies showed that compound 4l induced apoptotic cell death through a caspase-dependent mechanism and by regulating the p53-MDM2 signaling pathway in HT29 cells. Also, physicochemical predictions of compounds 4d, 4e, 4h, and 4i were examined in silico. The results revealed that the compounds possessed promising drug-likeness profiles.

Investigation of Gold Nanoparticle Naproxen-Derived Conjugations in Ovarian Cancer

Ovarian cancer, which is one of the most diagnosed cancer types among women, maintains its significance as a global health problem. Several drug candidates have been investigated for the potential treatment of ovarian cancer. Nonsteroidal anti-inflammatory drugs (NSAIDs) demonstrated anti-cancer activity through the inhibition of cyclooxygenase 2 (COX-2) and by inhibiting COX-2-dependent prostaglandin (PG) production. Naproxen is one of the most used NSAIDs and Naproxen-derived compounds (NDCs) may show potential treatment effects on cancer as chemotherapeutic drugs. Although there are successful drug development studies, the lack of solubility of these drug candidates in aqueous media results in limited bioavailability and high variability of patient responses during treatment. Low aqueous solubility is one of the main problems in the pharmaceutical industry in terms of drug development. Nanotechnology-based strategies provide solutions to hydrophobic drug limitations by increasing dispersion and improving internalization. In this study, two different NDCs (NDC-1 and NDC-2) bearing a thiosemicarbazide/1,2,4-triazole moiety were synthesized and tested for chemotherapeutic effects on ovarian cancer cells, which have a high COX-2 expression. To overcome the limited dispersion of these hydrophobic drugs, the drug molecules were conjugated to the surface of 13 nm AuNPs. Conjugation of drugs to AuNPs increased the distribution of drugs in aqueous media, and NDC@AuNP conjugates exhibited excellent colloidal stability for up to 8 weeks. The proposed system demonstrated an increased chemotherapeutic effect than the free drug counterparts with at least 5 times lower IC50 values. NDC@AuNP nanosystems induced higher apoptosis rates, which established a simple and novel way to investigate activity of prospective drugs in drug discovery research.

Design and Synthesis of Antifungal Candidates Containing Triazole Scaffold from Natural Rosin against Valsa mali for Crop Protection

Two series of dehydroabietyl-1,2,4-triazole-4-Schiff-based derivatives were synthesized from rosin to control plant fungal diseases. In vitro evaluation and screening of the antifungal activity were performed using Valsa mali, Colletotrichum orbiculare, Fusarium graminearum, Sclerotinia sclerotiorum, and Gaeumannomyces graminis. Compound 3f showed excellent fungicidal activity against V. mali (EC₅₀ = 0.537 μg/mL), which was significantly more effective than the positive control fluconazole (EC₅₀ = 4.707 μg/mL). Compound 3f also had a considerable protective effect against V. mali (61.57%-92.16%), which was slightly lower than that of fluconazole (85.17-100%) at 25-100 μg/mL. Through physiological and biochemical analyses, the preliminary mode of action of compound 3f against V. mali was explored. Ultrastructural observation of mycelia showed that compound 3f hindered the growth of the mycelium and destroyed the ultrastructure of V. mali seriously. Conductivity analysis and laser scanning confocal microscope staining showed that compound 3f changed cell-membrane permeability and caused accumulation of reactive oxygen species. The enzyme activity results showed that compound 3f significantly inhibited the activity of CYP51 (59.70%), SOD (76.9%), and CAT (67.86%). Molecular docking identified strong interaction energy between compound 3f and crystal structures of CYP51 (-11.18 kcal/mol), SOD (-9.25 kcal/mol), and CAT (-8.79 kcal/mol). These results provide guidance for the discovery of natural product-based antifungal pesticide candidates.

Formal [3 + 2] Cycloaddition of α-Imino Esters with Azo Compounds: Facile Construction of Pentasubstituted 1,2,4-Triazoline Skeletons

1,2,4-Triazole and 1,2,4-triazoline are important components of bioactive molecules and catalysts employed in organic synthesis. Therefore, the efficient synthesis of these components has received significant research attention. However, studies on their structural diversity remain lacking. Previously, we developed chiral phase-transfer-catalyzed asymmetric reactions of α-imino carbonyl compounds with α,β-unsaturated carbonyl compounds and haloalkanes. In this study, we demonstrate the formal [3 + 2] cycloaddition reaction of α-imino esters with azo compounds under Brønsted base catalysis, resulting in the corresponding 1,2,4-triazolines in high yields. The results revealed that a wide range of substrates and reactants can be applied, irrespective of their steric and electronic characteristics. The present reaction made the general preparation of 3-aryl pentasubstituted 1,2,4-triazolines possible for the first time. Furthermore, a mechanistic study suggested that the reaction proceeds without isomerization into the aldimine form.

Design, synthesis, and biological evaluation of pleuromutilin derivatives containing 1,2,4-triazole linker

A series of thioether pleuromutilin derivatives containing 1,2,4-triazole on the side chain of C14 were designed and synthesized. The in vitro antibacterial activities experiments of the synthesized derivatives showed that compounds 72 and 73 displayed superior in vitro antibacterial effect against MRSA minimal inhibitory concentration (MIC = 0.0625 μg/mL) than tiamulin (MIC = 0.5 μg/mL). The results of time-kill study and postantibiotic effect study indicated that compound 72 could inhibit the growth of MRSA quickly (-2.16 log₁₀ CFU/mL) and showed certain postantibiotic effect (PAE) time (exposure to 2 × MIC and 4 × MIC for 2 h, the PAE was 1.30 and 1.35 h) against MRSA. Furthermore, the binding mode between compound 72 and 50S ribosome of MRSA was explored by molecular docking and five hydrogen bonds were formed between compound 72 and 50S ribosome.

The Effect of Smart PEO-Coatings Impregnated with Corrosion Inhibitors on the Protective Properties of AlMg3 Aluminum Alloy

The protective coating with a self-organized microtubular structure was formed using plasma electrolytic oxidation (PEO) on AlMg3 aluminum alloy in the tartrate-fluoride electrolyte. This protective layer was further modified using corrosion inhibitors of the azole group (1,2,4-triazole, benzotriazole) and polymer material (polyvinilidene fluoride, PVDF). X-ray diffraction analysis and scanning electron microscopy with energy dispersive spectroscopy were used to study the morphology and composition of the obtained oxide coatings. The presence of the inhibitor in the PEO-layer was confirmed using micro-Raman spectroscopy and X-ray photoelectron spectroscopy. The level of corrosion protection of formed coatings as well as the effect of loaded inhibitors on the anticorrosion efficiency was evaluated using electrochemical impedance spectroscopy (EIS) and localized scanning techniques (SVET/SIET). The coating impregnation with corrosion inhibitors of the azole group significantly improves the corrosion characteristics of the material. Impregnation of the base PEO-layer with 1,2,4-triazole during 24 h results in a 36 times increase in the impedance modulus measured at the lowest frequency (|Z|_f=0.1Hz). Additional sealing of impregnated coating with polymer improves the corrosion stability of the treated material. On the base of the obtained data, the optimal way of protective inhibitor- and polymer-containing formation using surface treatment was suggested. The best barrier properties were established for hybrid coatings obtained by the immersion of a PEO-coated sample in 1,2,4-triazole solution for 24 h and following spraying the PVDF solution. The value of |Z|_f=0.1Hz for this protective layer increased by more than two orders of magnitude in comparison with the base PEO-layer. The three-stage mechanism of corrosion inhibition of the sample with smart inhibitor-containing coating was established.

Bio-Oriented Synthesis and Molecular Docking Studies of 1,2,4-Triazole Based Derivatives as Potential Anti-Cancer Agents against HepG2 Cell Line

Triazole-based acetamides serve as important scaffolds for various pharmacologically active drugs. In the present work, structural hybrids of 1,2,4-triazole and acetamides were furnished by chemically modifying 2-(4-isobutylphenyl) propanoic acid (1). Target compounds 7a-f were produced in considerable yields (70-76%) by coupling the triazole of compound 1 with different electrophiles under different reaction conditions. These triazole-coupled acetamide derivatives were verified by physiochemical and spectroscopic (HRMS, FTIR, 13CNMR, and 1HNMR,) methods. The anti-liver carcinoma effects of all of the derivatives against a HepG2 cell line were investigated. Compound 7f, with two methyl moieties at the ortho-position, exhibited the highest anti-proliferative activity among all of the compounds with an IC50 value of 16.782 µg/mL. 7f, the most effective anti-cancer molecule, also had a very low toxicity of 1.190.02%. Molecular docking demonstrates that all of the compounds, especially 7f, have exhibited excellent binding affinities of -176.749 kcal/mol and -170.066 kcal/mol to c-kit tyrosine kinase and protein kinase B, respectively. Compound 7f is recognized as the most suitable drug pharmacophore for the treatment of hepatocellular carcinoma.

Synthesis, characterization, molecular docking studies of new alkyl derivatives of 5-(2-bromo-4-fluorophenyl)-4-ethyl-4H- -1,2,4-triazole-3-thiol

The main goal of this article is to present the results of the synthesis of new alkyl derivatives of 5-(2-bromo4-fluorophenyl)-4-ethyl-4H-1,2,4-triazole-3-thiol and molecular docking studies against COX-1 and COX-2. Previous studies have established a wide range of biological activity of 1,2,4-triazole derivatives. Therefore, it was essential to determine how a new series of 1,2,4-triazole derivatives would provide potential anti-inflammatory activity. To reach the goal, raw alkyl derivatives of 5-(2-bromo-4-fluorophenyl)-4-ethyl-4H-1,2,4-triazole-3-thiols (2a-2i) from 5-(2-bromo-4-fluorophenyl)-4-ethyl-4H-1,2,4-triazole3-thiol (1e) were obtained. The structure of the synthesized compounds was confirmed by 1H-NMR elemental analyses. The individuality and purity of compounds were confirmed by the method of liquid chromatography-mass spectrometry. These compounds have a relatively simple synthesis scheme, which gives them an advantage in creating a potential drug, and the appearance of alkyl radicals in the molecule should positively affect pharmacokinetic indicators, stability, selectivity, and bioavailability. An in silico study was conducted for the synthesized compounds, namely molecular docking, in relation to the interaction with COX-1 and COX-2. Based on the selectivity indexes of binding modes observed for the selected compounds (2e, 2g) with active COX-1 centers, it was found that compounds can reliably exhibit their anti-inflammatory effect through the prostaglandin biosynthesis pathway, inhibiting COX-1 instead of COX-2. The effect of hydrophobic interactions of alkyl groups of 1,2,4-triazole derivatives on changes in affinity and selectivity to COX-1 or COX-2 has also been proven. Therefore, derivatives of 1,2,4 are promising candidates for improvement, further study, and future development of new, more powerful antiinflammatory drugs for therapeutic use.

A study of hypoglycemic activity of acids and salts containing 1,2,4-triazole

This article presents the study results of the hypoglycemic properties among 1,2,4-triazole derivatives synthesized at the Department of Physical and Colloidal Chemistry of the Zaporizhzhia State Medical University. Today, many people have a sedentary way of life, also most of their diet contains products that they frequently use, which increase the level of glucose in the blood, which can provoke the development of serious diseases. Therefore, to date, the creation of drugs that exhibit hypoglycemic activity and have a low level of toxicity remains an urgent task for medicine and pharmacy. In the first stage of our research, acute toxicity prediction was performed. The hypoglycemic activity of the synthesized compounds was assessed by performing an intraperitoneal glucose tolerance test (IPGTT) with a change in the blood glucose concentration of the animal after its single intraperitoneal administration in the form of a 40% solution at a dose of 2 g/kg of rat body weight. Thirty-eight compounds of the different classes were studied for hypoglycemic activity. Zinc (II) 2-{5-[(3,4-methoxyphenyl)-3H-1,2,4-triazole-3-yl]thio} acetate (3.18) showed the highest efficiency in terms of the ability to lower blood glucose levels, namely, by 27.3% (approximately 1.3 times).

Synthetic and medicinal perspective of 1,2,4-triazole as anticancer agents

Cancer is a disease leading to cause death. Many researchers are working a lot to design and develop different molecules having variety of scaffold i.e., coumarin, benzothiazole as anticancer agent. There is always an unmet need to develop new anticancer drugs to treat different types of cancer. Based on literature reports, it was found that 1,2,4-triazoles exhibited wide spectrum of biological action (particularly potent anticancer activity) as compared to constituent monocyclic compounds. In this review, we summarized novel 1,2,4-triazole fused/hybrid and poly-functionalized molecules as anticancer agents. Triazole may be fused with other heterocycles like pyrimidine, pyridine, piperidine, quinoxaline, quinazoline, thiadiazine indole etc. A clear explanation of method of synthesis, structure-activity relationship, and in vitro results with inhibitory concentration of new molecules are tabulated in this review article. .

The Effect of 1,2,4-Triazole-3-thiol Derivatives Bearing Hydrazone Moiety on Cancer Cell Migration and Growth of Melanoma, Breast, and Pancreatic Cancer Spheroids

4-Phenyl-3-[2-(phenylamino)ethyl]-1H-1,2,4-triazole-5(4H)-thione was used as a starting compound for the synthesis of the corresponding 1,2,4-triazol-3-ylthioacetohydrazide, which reacts with isatins and various aldehydes bearing aromatic and heterocyclic moieties provided target hydrazones. Their cytotoxicity was tested by the MTT assay against human melanoma IGR39, human triple-negative breast cancer (MDA-MB-231), and pancreatic carcinoma (Panc-1) cell lines. The selectivity of compounds towards cancer cells was also studied. In general, the synthesized compounds were more cytotoxic against the melanoma cell line. N′-(2-oxoindolin-3-ylidene)-2-((4-phenyl-5-(2-(phenylamino)ethyl)-4H-1,2,4-triazol-3-yl)thio)acetohydrazide, N′-((1H-pyrrol-2-yl)methylene)-2-((4-phenyl-5-(2-(phenylamino)ethyl)-4H-1,2,4-triazol-3-yl)thio)acetohydrazide and N′-(2-hydroxy-5-nitrobenzylidene)-2-((4-phenyl-5-(2-(phenylamino)ethyl)-4H-1,2,4-triazol-3-yl)thio)acetohydrazide were identified as the most active among all synthesized compounds in 3D cell cultures. N′-(4-(dimethylamino)benzylidene)-2-((4-phenyl-5-(2-(phenylamino)ethyl)-4H-1,2,4-triazol-3-yl)thio)acetohydrazide inhibited all cancer cell migration, was characterized as relatively more selective towards cancer cells, and could be further tested as an antimetastatic candidate.

Design and Synthesis of Novel 1,3,4-Oxadiazole and 1,2,4-Triazole Derivatives as Cyclooxygenase-2 Inhibitors with Anti-inflammatory and Antioxidant activity in LPS-stimulated RAW264.7 Macrophages

In an attempt to obtain new candidates with potential anti-inflammatory activity, two series of 1,3,4-oxadiazole based derivatives (8a-g) and 1,2,4-triazole based derivatives (10a,b and 11a-g) were synthesized and evaluated for their COX-1/COX-2 inhibitory activity. In vitro assays showed potent COX-2 inhibitory activity and selectivity of the novel designed compounds (IC50 = 0.04 - 0.16 μM, SI = 60.71 - 337.5) compared to celecoxib (IC50 = 0.045 μM, SI = 326.67). The anti-inflammatory and antioxidant activity of the synthesized compounds was investigated via testing their ability to inhibit pro-inflammatory [tumour necrosis factor (TNF-α) and interleukin-6 (IL-6)] and oxidative stress [nitric oxide (NO) and reactive oxygen species (ROS)] markers production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. Most of the novel compounds exhibited potent anti-inflammatory and antioxidant activity. In particular, the novel compounds showed excellent IL-6 inhibitory activity (IC50 = 0.96 - 11.14 μM) when compared to celecoxib (IC50 = 13.04 μM) and diclofenac sodium (IC50 = 22.97 μM). Moreover, the most potent and selective COX-2 inhibitor 11c (IC50 = 0.04 μM, SI = 337.5) displayed significantly higher activity against NO and ROS production compared to celecoxib (IC50 = 2.60 and 3.01 μM vs. 16.47 and 14.30 μM, respectively). Molecular modelling studies of the novel designed molecules into COX-2 active sites analysed their binding affinity. In-silico simulation studies indicated their acceptable physicochemical properties and pharmacokinetic profiles. This study suggests that the novel synthesized COX-2 inhibitors exert potent anti-inflammatory and antioxidant activity, highlighting their potential as promising therapeutic agents for the treatment of inflammation and oxidative stress-related diseases.

Synthesis and Antimicrobial Activity Screening of Piperazines Bearing N,N'-Bis(1,3,4-thiadiazole) Moiety as Probable Enoyl-ACP Reductase Inhibitors

A new N,N'-disubstituted piperazine conjugated with 1,3,4-thiadiazole and 1,2,4-triazole was prepared and the chemical structures were identified by IR, NMR and elemental analysis. All the prepared compounds were tested for their antimicrobial activity. The antimicrobial results indicated that the tested compounds showed significant antibacterial activity against gram-negative strains, especially E. coli, relative to gram-positive bacteria. Docking analysis was performed to support the biological results; binding modes with the active site of enoyl reductase amino acids from E. coli showed very good scores, ranging from -6.1090 to -9.6184 kcal/mol. Correlation analysis was performed for the inhibition zone (nm) and the docking score.

Adamantane-Monoterpenoid Conjugates Linked via Heterocyclic Linkers Enhance the Cytotoxic Effect of Topotecan

Inhibiting tyrosyl-DNA phosphodiesterase 1 (TDP1) is a promising strategy for increasing the effectiveness of existing antitumor therapy since it can remove the DNA lesions caused by anticancer drugs, which form covalent complexes with topoisomerase 1 (TOP1). Here, new adamantane-monoterpene conjugates with a 1,2,4-triazole or 1,3,4-thiadiazole linker core were synthesized, where (+)-and (-)-campholenic and (+)-camphor derivatives were used as monoterpene fragments. The campholenic derivatives 14a-14b and 15a-b showed activity against TDP1 at a low micromolar range with IC₅₀ ~5-6 μM, whereas camphor-containing compounds 16 and 17 were ineffective. Surprisingly, all the compounds synthesized demonstrated a clear synergy with topotecan, a TOP1 poison, regardless of their ability to inhibit TDP1. These findings imply that different pathways of enhancing topotecan toxicity other than the inhibition of TDP1 can be realized.

Investigation of the antimicrobial and antifungal activities of some 1,2,4-triazole derivatives

This article presents the results of the study of the antimicrobial and antifungal properties among 1,2,4-triazole derivatives synthesized at the Department of Physical and Colloidal Chemistry of the Zaporizhzhia State Medical University. Previous studies have established the antimicrobial and antifungal activity of 1,2,4-triazole derivatives. Therefore, it was reasonable to investigate highly effective substances with antimicrobial and antifungal properties among synthesized compounds. In the first stage of our research, acute toxicity prediction was performed. The antimicrobial and antifungal properties were carried out by the method of &#8220;serial dilutions&#8221; on a liquid nutrient. Forty-seven compounds of the different classes were studied for these types of activities. According to our research, derivatives of 3-amino-1,2,4-triazole showed better performance than 3-thio-1,2.4-triazoles for Staphylococcus aureus and Candida albicans. 5-(1&#1053;-tetrazole-1-&#1110;l)methyl-4&#1053;- -1,2,4-triazole-3-yl-1-(5-nitrofuran-2-yl)methanimin (11.6) was showed the greatest antimicrobial and antifungal activity. Deeper research for compound 11.6 was done by diffusion in agar (method of &#8220;wells&#8221;). Studies have shown that molecule 11.6 showed antimicrobial and antifungal action to the studied test strains at a concentration of 2 &#956;g/ml. Hence, this compound can be developed as a helpful therapeutic agent after establishing its safety pharmacology and toxicity.

Synthesis and Biological Evaluation of 1,2,4-Triazole Thioethers as Both Potential Virulence Factor Inhibitors against Plant Bacterial Diseases and Agricultural Antiviral Agents against Tobacco Mosaic Virus Infections

Targeting the virulence factors of phytopathogenic bacteria is an innovative strategy for alleviating or eliminating the pathogenicity and rapid outbreak of plant microbial diseases. Therefore, several types of 1,2,4-triazole thioethers bearing an amide linkage were prepared and screened to develop virulence factor inhibitors. Besides, the 1,2,4-triazole scaffold was exchanged by a versatile 1,3,4-oxadiazole core to expand molecular diversity. Bioassay results revealed that a 1,2,4-triazole thioether A₁₀ bearing a privileged N-(3-nitrophenyl)acetamide fragment was extremely bioactive against Xanthomonas oryzae pv. oryzae (Xoo) with an EC₅₀ value of 5.01 μg/mL. Label-free quantitative proteomics found that compound A₁₀ could significantly downregulate the expression of Xoo's type III secretion system (T3SS) and transcription activator-like effector (TALE) correlative proteins. Meanwhile, qRT-PCR detection revealed that the corresponding gene transcription levels of these virulence factor-associated proteins were substantially inhibited after being triggered by compound A₁₀. As a result, the hypersensitive response and pathogenicity were strongly depressed, indicating that a novel virulence factor inhibitor (A₁₀) was probably discovered. In vivo anti-Xoo trials displayed that compound A₁₀ yielded practicable control efficiency (54.2-59.6%), which was superior to thiadiazole-copper and bismerthiazol (38.1-44.9%). Additionally, compound A₁₀ showed an appreciable antiviral activity toward tobacco mosaic virus (TMV) with the curative and protective activities of 54.6 and 76.4%, respectively, which were comparable to ningnanmycin (55.2 and 60.9%). This effect was further validated and visualized by the inoculation test using GFP-labeled TMV, thereby leading to the reduced biosynthesis of green-fluorescent TMV on Nicotiana benthamiana. Given the outstanding features of compound A₁₀, it should be deeply developed as a versatile agricultural chemical.

A Zn(II)-Based Sql Type 2D Coordination Polymer as a Highly Sensitive and Selective Turn-On Fluorescent Probe for Al3

A luminescent coordination polymer with the overall formula {[Zn(tr2btd)(bpdc)]∙DMF}n (where tr2btd = 4,7-di(1H-1,2,4-triazol-1-yl)-2,1,3-benzothiadiazole; bpdc = 4,4'-biphenyldicarboxylate) was synthesized and characterized by single-crystal and powder X-ray diffraction, thermogravimetric, infrared spectroscopy, and elemental analyses. Luminescent properties of the obtained compound were studied in detail both in the solid state and as a suspension in N,N-dimethylacetamide (DMA). It was found that {[Zn(tr2btd)(bpdc)]∙DMF}n exhibits bright turquoise luminescence with excellent quantum efficiency and demonstrates turn-on fluorescence enhancement effect upon soaking in DMA Al3+ solution. Fluorescence titration experiments were carried out and the detection limit for Al3+ ions was calculated to be 120 nM, which is among the lowest reported values for similar materials. Moreover, compound demonstrated excellent selectivity and reusability, and the mechanism of the response is discussed. These results indicate that {[Zn(tr2btd)(bpdc)]∙DMF}n is a promising probe for sensitive fluorescent Al3+ detection.

The [1,2,4]Triazolo[4,3-a]pyridine as a New Player in the Field of IDO1 Catalytic Holo-Inhibitors

Inhibitors of indoleamine 2,3-dioxygenase 1 (IDO1) are considered a promising strategy in cancer immunotherapy as they are able to boost the immune response and to work in synergy with other immunotherapeutic agents. Despite the fact that no IDO1 inhibitor has been approved so far, recent studies have shed light on the additional roles that IDO1 mediates beyond its catalytic activity, conferring new life to the field. Here we present a novel class of compounds originated from a structure-based virtual screening made on IDO1 active site. The starting hit compound is a novel chemotype based on a [1,2,4]triazolo[4,3-a]pyridine scaffold, so far underexploited among the heme binding moieties. Thanks to the rational and in silico-guided design of analogues, an improvement of the potency to sub-micromolar levels has been achieved, with excellent in vitro metabolic stability and exquisite selectivity with respect to other heme-containing enzymes.

Advances in the application of 1,2,4-triazole-containing hybrids as anti-tuberculosis agents

Tuberculosis is a deadly communicable disease caused by the bacillus Mycobacterium tuberculosis (MTB), and pulmonary tuberculosis accounts for over 80% of the total cases. The 1,2,4-triazole is a privileged structure in the discovery of new drugs, and its derivatives act on various targets in MTB. In particular, 1,2,4-triazole hybrids can not only exert dual or multiple antitubercular mechanisms of action but also have the potential to enhance efficacy and reduce side effects. The present work aims to summarize the current status of 1,2,4-triazole hybrids as potential antitubercular agents, covering articles published between 2010 and 2020, to aid the further rational design of novel potential drug candidates endowed with higher efficacy, better compliance and fewer side effects.

New N-Substituted-1,2,4-triazole Derivatives of Pyrrolo[3,4-d]pyridazinone with Significant Anti-Inflammatory Activity-Design, Synthesis and Complementary In Vitro, Computational and Spectroscopic Studies

Regarding that the chronic use of commonly available non-steroidal and anti-inflammatory drugs (NSAIDs) is often restricted by their adverse effects, there is still a current need to search for and develop new, safe and effective anti-inflammatory agents. As a continuation of our previous work, we designed and synthesized a series of 18 novel N-substituted-1,2,4-triazole-based derivatives of pyrrolo[3,4-d]pyridazinone 4a-c-9a-c. The target compounds were afforded via a convenient way of synthesis, with good yields. The executed cell viability assay revealed that molecules 4a-7a, 9a, 4b-7b, 4c-7c do not exert a cytotoxic effect and were qualified for further investigations. According to the performed in vitro test, compounds 4a-7a, 9a, 4b, 7b, 4c show significant cyclooxygenase-2 (COX-2) inhibitory activity and a promising COX-2/COX-1 selectivity ratio. These findings are supported by a molecular docking study which demonstrates that new derivatives take position in the active site of COX-2 very similar to Meloxicam. Moreover, in the carried out in vitro evaluation within cells, the title molecules increase the viability of cells pre-incubated with the pro-inflammatory lipopolysaccharide and reduce the level of reactive oxygen and nitrogen species (RONS) in induced oxidative stress. The spectroscopic and molecular modeling study discloses that new compounds bind favorably to site II(m) of bovine serum albumin. Finally, we have also performed some in silico pharmacokinetic and drug-likeness predictions. Taking all of the results into consideration, the molecules belonging to series a (4a-7a, 9a) show the most promising biological profile.

Synthesis and insecticidal activity of novel 1,2,4-triazole derivatives containing trifluoroacetyl moieties

A series of compounds containing trifluoroacetyl groups were synthesized, and their insecticidal activity against Nilaparvata lugens and Aphis craccivora was evaluated. The compound structure was identified by NMR, HRMS, and single-crystal diffraction. The bioassay results indicated that compound 4-1 (R¹ is chloropyridine, R² is H), 4-2 (R¹ is chlorothiazole, R² is H) and 4-19 (R¹ is benzyl, R² is isopropyl) had the best activity against Nilaparvata lugens (93.5%, 94.1% and 95.5%) at 100 mg/L concentration. The effect of different substituents of R¹ or R² on the activity was studied through the structure-activity relationship. Molecular docking of compounds 4-1 and 4-2 was discussed.

Halting Tumor Progression via Novel Non-Hydroxamate Triazole-Based Mannich Bases MMP-2/9 Inhibitors; Design, Microwave-Assisted Synthesis, and Biological Evaluation

Matrix metalloproteinases (MMPs) are key signaling modulators in the tumor microenvironment. Among MMPs, MMP-2 and MMP-9 are receiving renewed interest as validated druggable targets for halting different tumor progression events. Over the last decades, a diverse range of MMP-2/9 inhibitors has been identified starting from the early hydroxamic acid-based peptidomimetics to the next generation non-hydroxamates. Herein, focused 1,2,4-triazole-1,2,3-triazole molecular hybrids with varying lengths and decorations, mimicking the thematic features of non-hydroxamate inhibitors, were designed and synthesized using efficient protocols and were alkylated with pharmacophoric amines to develop new Mannich bases. After full spectroscopic characterization the newly synthesized triazoles tethering Mannich bases were subjected to safety assessment via MTT assay against normal human fibroblasts, then evaluated for their potential anticancer activities against colon (Caco-2) and breast (MDA-MB 231) cancers. The relatively lengthy bis-Mannich bases 15 and 16 were safer and more potent than 5-fluorouracil with sub-micromolar IC₅₀ and promising selectivity to the screened cancer cell lines rather than normal cells. Both compounds upregulated p53 (2–5.6-fold) and suppressed cyclin D expression (0.8–0.2-fold) in the studied cancers, and thus, induced apoptosis. 15 was superior to 16 in terms of cytotoxic activities, p53 induction, and cyclin D suppression. Mechanistically, both were efficient MMP-2/9 inhibitors with comparable potencies to the reference prototype hydroxamate-based MMP inhibitor NNGH at their anticancer IC₅₀ concentrations. 15 (IC₅₀ = 0.143 µM) was 4-fold more potent than NNGH against MMP-9 with promising selectivity (3.27-fold) over MMP-2, whereas 16 was comparable to NNGH. Concerning MMP-2, 16 (IC₅₀ = 0.376 µM) was 1.2-fold more active than 15. Docking simulations predicted their possible binding modes and highlighted the possible structural determinants of MMP-2/9 inhibitory activities. Computational prediction of their physicochemical properties, ADMET, and drug-likeness metrics revealed acceptable drug-like criteria.

Aerobic biodegradation of emerging azole contaminants by return activated sludge and enrichment cultures

Azoles are an emerging class of contaminants with a growing ubiquitous presence in the environment. This study investigates the aerobic microbial degradation of four azoles, pyrazole (PA), 1,2,4-triazole (TA), benzotriazole (BTA) and 5-methylbenzotriazole (5-MBTA), with return activated sludge and microbial enrichment cultures. Slow degradation of PA was observed in the presence of glucose and NH₄⁺ with a peak degradation rate of 0.5 mg d^-1 gVSS^-1. TA was found to be highly persistent, with no significant degradation observed in 6-8 months under any incubation condition. In contrast, the benzotriazoles were readily degraded at faster rates in all incubation conditions. The degradation rates observed for BTA and 5-MBTA, when provided as the sole substrates, were 8.1 and 16.5 mg d^-1 gVSS^-1, respectively. Two enrichment cultures, one degrading BTA and the other degrading 5-MBTA, were developed from the activated sludge. Mass balance studies revealed complete mineralization of 5-MBTA and partial breakdown of BTA by the enrichment cultures. Nocardioides sp. and Pandoraea pnomenusa were the most abundant bacteria in the BTA and 5-MBTA degrading enrichment cultures, respectively. The research shows large differences in the biodegradability of various azoles, ranging from complete mineralization of 5-MBTA to complete persistence for TA.

Synthesis, Crystal Structure, and Luminescence of Cadmium(II) and Silver(I) Coordination Polymers Based on 1,3-Bis(1,2,4-triazol-1-yl)adamantane

Coordination polymers with a new rigid ligand 1,3-bis(1,2,4-triazol-1-yl)adamantane (L) were prepared by its reaction with cadmium(II) or silver(I) nitrates. Crystal structure of the coordination polymers was determined using single-crystal X-ray diffraction analysis. Silver formed two-dimensional coordination polymer [Ag(L)NO₃]_n, in which metal ions are linked by 1,3-bis(1,2,4-triazol-1-yl)adamantane ligands, coordinated by nitrogen atoms at positions 2 and 4 of 1,2,4-triazole rings. Layers of the coordination polymer consist of rare 18- and 30-membered {Ag₂L₂} and {Ag₄L₄} metallocycles. Cadmium(II) nitrate formed two kinds of one-dimensional coordination polymers depending on the metal-to-ligand ratio used in the synthesis. Coordination polymer [Cd(L)₂(NO₃)₂]_n was obtained in case of a 1:2 M:L ratio, while for M:L = 2:1 product {[Cd(L)(NO₃)₂(CH₃OH)]·0.5CH₃OH}_n was isolated. All coordination polymers demonstrated ligand-centered emission near 450 nm upon excitation at 370 nm.

Structural Insights and Docking Analysis of Adamantane-Linked 1,2,4-Triazole Derivatives as Potential 11β-HSD1 Inhibitors

The solid-state structural analysis and docking studies of three adamantane-linked 1,2,4-triazole derivatives are presented. Crystal structure analyses revealed that compound 2 crystallizes in the triclinic P-1 space group, while compounds 1 and 3 crystallize in the same monoclinic P21/c space group. Since the only difference between them is the para substitution on the aryl group, the electronic nature of these NO2 and halogen groups seems to have no influence over the formation of the solid. However, a probable correlation with the size of the groups is not discarded due to the similar intermolecular disposition between the NO2/Cl substituted molecules. Despite the similarities, CE-B3LYP energy model calculations show that pairwise interaction energies vary between them, and therefore the total packing energy is affected. HOMO-LUMO calculated energies show that the NO2 group influences the reactivity properties characterizing the molecule as soft and with the best disposition to accept electrons. Further, in silico studies predicted that the compounds might be able to inhibit the 11β-HSD1 enzyme, which is implicated in obesity and diabetes. Self- and cross-docking experiments revealed that a number of non-native 11β-HSD1 inhibitors were able to accurately dock within the 11β-HSD1 X-ray structure 4C7J. The molecular docking of the adamantane-linked 1,2,4-triazoles have similar predicted binding affinity scores compared to the 4C7J native ligand 4YQ. However, they were unable to form interactions with key active site residues. Based on these docking results, a series of potentially improved compounds were designed using computer aided drug design tools. The docking results of the new compounds showed similar predicted 11β-HSD1 binding affinity scores as well as interactions to a known potent 11β-HSD1 inhibitor.

Novel N-bridged pyrazole-1-carbothioamides with potential antiproliferative activity: design, synthesis, in vitro and in silico studies

Thiazole-substituted pyrazole is an important structural feature of many bioactive compounds, including antiviral, antitubercular, analgesic and anticancer agents. Herein we describe an efficient and facile approach for the synthesis of two series of 36 novel N-bridged pyrazole-1-phenylthiazoles. The antiproliferative activity of a set of representative compounds was evaluated in vitro against different human cancer cell lines. Among the identified compounds, compound 18 showed potent anticancer activity against the examined cancer cell lines. The in silico molecular docking study revealed that compound 18 possesses high binding affinity toward both SK1 and CDK2. Overall, these results indicate that compound 18 is a promising lead anticancer compound which may be exploited for development of antiproliferative drugs.

Novel (+)-Neoisopulegol-Based O-Benzyl Derivatives as Antimicrobial Agents

Discovery of novel antibacterial agents with new structures, which combat pathogens is an urgent task. In this study, a new library of (+)-neoisopulegol-based O-benzyl derivatives of aminodiols and aminotriols was designed and synthesized, and their antimicrobial activity against different bacterial and fungal strains were evaluated. The results showed that this new series of synthetic O-benzyl compounds exhibit potent antimicrobial activity. Di-O-benzyl derivatives showed high activity against Gram-positive bacteria and fungi, but moderate activity against Gram-negative bacteria. Therefore, these compounds may serve a good basis for antibacterial and antifungal drug discovery. Structure-activity relationships were also studied from the aspects of stereochemistry of the O-benzyl group on cyclohexane ring and the substituent effects on the ring system.

Triazole-Modified Peptidomimetics: An Opportunity for Drug Discovery and Development

Peptidomimetics play a fundamental role in drug design due to their preferential properties regarding natural peptides. In particular, compounds possessing nitrogen-containing heterocycles have been intensively studied in recent years. The triazolyl moiety incorporation decreases the molecule susceptibility to enzymatic degradation, reduction, hydrolysis, and oxidation. In fact, peptides containing triazole rings are a typical example of peptidomimetics. They have all the advantages over classic peptides. Both efficient synthetic methods and biological activity make these systems an interesting and promising object of research. Peptide triazole derivatives display a diversity of biological properties and can be obtained via numerous synthetic strategies. In this review, we have highlighted the importance of the triazole-modified peptidomimetics in the field of drug design. We present an overview on new achievements in triazolyl-containing peptidomimetics synthesis and their biological activity as inhibitors of enzymes or against cancer, viruses, bacteria, or fungi. The relevance of above-mentioned compounds was confirmed by their comparison with unmodified peptides.

Design, Synthesis and Anticancer Activity of New Polycyclic: Imidazole, Thiazine, Oxathiine, Pyrrolo-Quinoxaline and Thienotriazolopyrimidine Derivatives

In this article, we showed the synthesis of new polycyclic aromatic compounds, such as thienotriazolopyrimidinones, N-(thienotriazolopyrimidine) acetamide, 2-mercapto-thienotriazolo-pyrimidinones, 2-(((thieno-triazolopyrimidine) methyl) thio) thieno-triazolopyrimidines, thieno-pyrimidotriazolo-thiazines, pyrrolo-triazolo-thienopyrimidines, thienopyrimido-triazolopyrrolo-quinoxalines, thienopyrimido-triazolo-pyrrolo-oxathiino-quinoxalinones, 1,4-oxathiino-pyrrolo- triazolothienopyrimidinones, imidazopyrrolotriazolothienopyrimidines and 1,2,4-triazoloimidazo- pyrrolotriazolothienopyrimidindiones, based on the starting material 2,3-diamino-6-benzoyl-5- methylthieno[2,3-d]pyrimidin-4(3H)-one (3). The chemical structures were confirmed using many spectroscopic ways (IR, ¹H, ¹³C, −NMR and MS) and elemental analyses. A series of thiazine, imidazole, pyrrole, thienotriazolopyrimidine derivatives were synthesized and evaluated for their antiproliferative activity against four human cancer cell lines, i.e., CNE2 (nasopharyngeal), KB (oral), MCF-7 (breast) and MGC-803 (gastric) carcinoma cells. The compounds 20, 19, 17, 16 and 11 showed significant cytotoxicity against types of human cancer cell lines.

1,2,4-Triazoles as Important Antibacterial Agents

The global spread of drug resistance in bacteria requires new potent and safe antimicrobial agents. Compounds containing the 1,2,4-triazole ring in their structure are characterised by multidirectional biological activity. A large volume of research on triazole and their derivatives has been carried out, proving significant antibacterial activity of this heterocyclic core. This review is useful for further investigations on this scaffold to harness its optimum antibacterial potential. Moreover, rational design and development of the novel antibacterial agents incorporating 1,2,4-triazole can help in dealing with the escalating problems of microbial resistance.

Design, synthesis, and anticonvulsant effects evaluation of nonimidazole histamine H3 receptor antagonists/inverse agonists containing triazole moiety

Histamine H₃ receptors (H₃R) antagonists/inverse agonists are becoming a promising therapeutic approach for epilepsy. In this article, novel nonimidazole H₃R antagonists/inverse agonists have been designed and synthesised via hybriding the H₃R pharmacophore (aliphatic amine with propyloxy chain) with the 1,2,4-triazole moiety as anticonvulsant drugs. The majority of antagonists/inverse agonists prepared here exerted moderate to robust activities in cAMP-response element (CRE) luciferase screening assay. 1-(3-(4-(3-Phenyl-4H-1,2,4-triazol-4-yl)phenoxy)propyl)piperidine (3l) and 1-(3-(4-(3-(4-chlorophenyl)-4H-1,2,4-triazol-4-yl)phenoxy)propyl)piperidine (3m) displayed the highest H₃R antagonistic activities, with IC₅₀ values of 7.81 and 5.92 nM, respectively. Meanwhile, the compounds with higher H₃R antagonistic activities exhibited protection for mice in maximal electroshock seizure (MES)-induced convulsant model. Moreover, the protection of 3m against the MES induced seizures was fully abrogated when mice were co-treated with RAMH, a CNS-penetrant H₃R agonist, which suggested that the potential therapeutic effect of 3m was through H₃R. These results indicate that the attempt to find new anticonvulsant among H₃R antagonists/inverse agonists is practicable.

Structure, In Vitro Screening and Docking Studies

A series of 1,2,4-triazole derivatives were synthesized and assigned as potential anti-tuberculosis substances. The molecular and crystal structures for the model compounds C1, C12, and C13 were determined using X-ray analysis. The X-ray investigation confirmed the synthesis pathway and the assumed molecular structures for analyzed 1,2,4-triazol-5-thione derivatives. The conformational preferences resulting from rotational degrees of freedom of the 1,2,4-triazole ring substituents were characterized. The lipophilicity (logP) and electronic parameters as the energy of frontier orbitals, dipole moments, NBO net charge distribution on the atoms, and electrostatic potential distribution for all structures were calculated at AM1 and DFT/B3LYP/6-311++G(d,p) level. The in vitro test was done against M. tuberculosis H37Ra, M. phlei, M. smegmatis, and M. timereck. The obtained results clearly confirmed the antituberculosis potential of compound C4, which turned out to be the most active against Mycobacterium H37Ra (MIC = 0.976 μg/mL), Mycobaterium pheli (MIC = 7.81 μg/mL) and Mycobacerium timereck (62.6 μg/mL). Satisfactory results were obtained with compounds C8, C11, C14 versus Myc. H37Ra, Myc. pheli, Myc. timereck (MIC = 31.25-62.5 μg/mL). The molecular docking studies were carried out for all investigated compounds using the Mycobacterium tuberculosis cytochrome P450 CYP121 enzyme as molecular a target connected with antimycobacterial activity.

Design, Synthesis and Fungicidal Activity of New 1,2,4-Triazole Derivatives Containing Oxime Ether and Phenoxyl Pyridinyl Moiety

A series of novel 1,2,4-triazole derivatives containing oxime ether and phenoxy pyridine moiety were designed and synthesized. The new compounds were identified by nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry (HRMS). Compound (Z)-1-(6-(4-nitrophenoxy)pyridin-3-yl)-2-(1H-1,2,4-triazol-1-yl)ethan-1-one O-methyl oxime (5a18) was further confirmed by X-ray single crystal diffraction. Their antifungal activities were evaluated against eight phytopathogens. The in vitro bioassays indicated that most of the title compounds displayed moderate to high fungicidal activities. Compound (Z)-1-(6-(4-bromo-2-chlorophenoxy)pyridin-3-yl)-2-(1H-1,2,4-triazol-1-yl)ethan-1-one O-methyl oxime (5a4) exhibited a broad-spectrum antifungal activities with the EC₅₀ values of 1.59, 0.46, 0.27 and 11.39 mg/L against S. sclerotiorum, P. infestans, R. solani and B. cinerea, respectively. Compound (Z)-1-(6-(2-chlorophenoxy)pyridin-3-yl)-2-(1H-1,2,4-triazol-1-yl)ethan-1-one O-benzyl oxime (5b2) provided the lowest EC₅₀ value of 0.12 mg/L against S. sclerotiorum, which were comparable to the commercialized difenoconazole. Moreover, homologous modeling and molecular docking disclosed possible binding modes of compounds 5a4 and 5b2 with CYP51. This work provided useful guidance for the discovery of new 1,2,4-triazole fungicides.

5-[Aryloxypyridyl (or nitrophenyl)]-4H-1,2,4-triazoles as novel flexible benzodiazepine analogues: Synthesis, receptor binding affinity and lipophilicity-dependent anti-seizure onset of action

A new series of 5-(2-aryloxy-4-nitrophenyl)-4H-1,2,4-triazoles and 5-(2-aryloxy-3-pyridyl)-4H-1,2,4-triazoles, possessing C-3 thio or alkylthio substituents, was synthesized and evaluated for their benzodiazepine receptor affinity and anti-seizure activity. These analogues revealed similar to significantly superior affinity to GABA_A/benzodiazepine receptor complex (IC₅₀ values of 0.04-4.1 nM), relative to diazepam as the reference drug (IC₅₀ value of 2.4 nM). To determine the onset of anti-seizure activity, the time-dependent effectiveness of i.p. administration of compounds on pentylenetetrazole induced seizure threshold was studied and a very good relationship was observed between the lipophilicity (cLogP) and onset of action of studied analogues (r² = 0.964). The minimum effective dose of the compounds, determined at the time the analogues showed their highest activity, was demonstrated to be 0.025-0.1 mg/kg, relative to diazepam (0.025 mg/kg).

Crystal structure, thermal properties and detonation characterization of bis(5-amino-1,2,4-triazol-4-ium-3-yl)methane dinitrate

Bis(5-amino-1,2,4-triazol-4-ium-3-yl)methane dinitrate, BATZM·(NO₃)₂ or C₅H₁₀N₈²⁺·2NO₃^-, was synthesized and its crystal structure determined by single-crystal X-ray diffraction. It crystallizes in the space group Pbcn (orthorhombic) with Z = 4. BATZM·(NO₃)₂ is a V-shaped molecule where hydrogen bonds form a two-dimensional corrugated sheet with reasonable chemical geometry and no disorder. The specific molar heat capacity (C_p,m) of BATZM·(NO₃)₂ was determined using the continuous C_p mode of a microcalorimeter and theoretical calculations, and the C_p,m value is 366.14 J K^-1 mol^-1 at 298.15 K. The relative deviations between the theoretical and experimental values of C_p,m, H_T - H_298.15K and S_T - S_298.15K of BATZM·(NO₃)₂ are almost equivalent at each temperature. The detonation velocity (D) and detonation pressure (P) were estimated using the nitrogen equivalent equation according to the experimental density; BATZM·(NO₃)₂ has a higher detonation velocity (7927.47 ± 3.63 m s^-1) and detonation pressure (27.50 ± 0.03 GPa) than 2,4,6-trinitrotoluene (TNT). The above results for BATZM·(NO₃)₂ are compared with those of bis(5-amino-1,2,4-triazol-3-yl)methane (BATZM) and bis(5-amino-1,2,4-triazol-4-ium-3-yl)methane dihydrochloride (BATZM·Cl₂), and the effect of nitrate formation is discussed.

1,2,4-Triazole hybrids with potential antibacterial activity against methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) has developed numerous mechanisms of virulence and strategies to evade the human immune system, and it can be transmitted between humans, animals, and the environment. Thus, MRSA is an important cause of morbidity and mortality in both hospitals and in the community, creating an urgent demand for the development of novel anti-MRSA candidates. The 1,2,4-triazole nucleus is a bioisostere of amide, ester, and carboxylic acid, and the 1,2,4-triazole ring is found in many compounds with diverse biological effects. 1,2,4-Triazole derivatives could exert their antibacterial activity through inhibition of efflux pumps, filamentous temperature-sensitive protein Z, penicillin-binding protein, DNA gyrase, and topoisomerase IV, and they play an important role in the discovery of novel antibacterial agents. Among them, 1,2,4-triazole hybrids, which have the potential to exert dual/multiple mechanisms of action, possess a promising broad-spectrum antibacterial activity against a panel of clinically important drug-resistant pathogens including MRSA. This review outlines the recent developments of 1,2,4-triazole hybrids with a potential anti-MRSA activity, covering articles published between 2010 and 2020. The mechanisms of action, critical aspects of their design, and structure-activity relationships are also discussed.

Synthesis of benzoylthiourea derivatives and analysis of their antibacterial performance against planktonic Staphylococcus aureus and its biofilms

Following the appearance of several antimicrobial agents to control the spread of infections, two major challenges have emerged: (i) the occurrence and blowout of multiresistant bacteria and the increase of chronic diseases and (ii) difficult-to-eradicate infections. In this study, we tested five benzoylthiourea derivatives for their ability to inhibit and stop bacterial growth and evaluated the possible influence of 1,2,4-triazolyl-benzoylthiourea derivative 4 on the formation and eradication of Staphylococcus aureus biofilms. Benzoylthiourea derivatives 4, 6, 10, 11 and 13 were obtained in one or two steps with low cost and subjected to tests to identify their minimum inhibitory concentration (MIC) and minimum bactericidal concentration. In vitro tests were also performed to assess their effects on biofilm formation and in preformed biofilms and scanning electron microscopy was used to visualize the effects on biofilm formation. The 1,2,4-triazolyl-benzoylthiourea derivative 4 showed bacteriostatic activity against the S. aureus HU25 clinical strain with an MIC of 16 µg ml^-1 , which is below the toxic concentration (at 2500 µg ml^-1 , 62·25% of the cells remained viable). Compound 4 also effectively prevented biofilm formation at the three subinhibitory concentrations tested (1/2 MIC, 1/4 MIC and 1/8 MIC) as confirmed by scanning electron microscopy. For breakdown of formed biofilms, the main influence was at a subinhibitory concentration (1/2 MIC). These findings make compound 4 a strong candidate for studies on the development of new antimicrobial and antibiofilm agents.

Crystal structure, thermal behaviour and detonation characterization of bis(4,5-diamino-1,2,4-triazol-3-yl)methane monohydrate

Bis(4,5-diamino-1,2,4-triazol-3-yl)methane monohydrate (BDATZM·H₂O or C₅H₁₀N₁₀·H₂O) was synthesized and its crystal structure characterized by single-crystal X-ray diffraction; it belongs to the space group P-1 (triclinic) with Z = 2. The structure of BDATZM·H₂O can be described as a two-dimensional ladder plane with extensive hydrogen bonding and no disorder. The thermal behaviour was studied under non-isothermal conditions by differential scanning calorimetry (DSC) and thermogravimetric/differential thermogravimetric (TG/DTG) methods. The detonation velocity (D) and detonation pressure (P) of BDATZM were estimated using the nitrogen equivalent equation according to the experimental density. A comparison between BDATZM·H₂O and bis(5-amino-1,2,4-triazol-3-yl)methane (BATZM) was made to determine the effect of the amino group; the results suggest that the amino group increases the hydrophilicity, space utilization and energy, and decreases the thermal stability and symmetry of the resulting compound.

Crystal structure, thermal properties and detonation characterization of bis(5-amino-1,2,4-triazol-4-ium-3-yl)methane dichloride

Bis(5-amino-1,2,4-triazol-4-ium-3-yl)methane dichloride (BATZM·Cl₂ or C₅H₁₀N₈²⁺·2Cl^-) was synthesized and crystallized, and the crystal structure was characterized by single-crystal X-ray diffraction; it belongs to the space group C2/c (monoclinic) with Z = 4. The structure of BATZM·Cl₂ can be described as a V-shaped molecule with reasonable chemical geometry and no disorder, and its one-dimensional structure can be described as a rhombic helix. The specific molar heat capacity (C_p,m) of BATZM·Cl₂ was determined using the continuous C_p mode of a microcalorimeter and theoretical calculations, and the C_p,m value is 276.18 J K^-1 mol^-1 at 298.15 K. The relative deviations between the theoretical and experimental values of C_p,m, H_T - H_298.15K and S_T - S_298.15K of BATZM·Cl₂ are almost equivalent at each temperature. The detonation velocity (D) and detonation pressure (P) of BATZM·Cl₂ were estimated using the nitrogen equivalent equation according to the experimental density; BATZM·Cl₂ has a higher detonation velocity (7143.60 ± 3.66 m s^-1) and detonation pressure (21.49 ± 0.03 GPa) than TNT. The above results for BATZM·Cl₂ are compared with those of bis(5-amino-1,2,4-triazol-3-yl)methane (BATZM) and the effect of salt formation on them is discussed.

Crystal structure and Hirshfeld surface analysis of 4,4'-(propane-1,3-diyl)bis(4H-1,2,4-triazol-1-ium) penta-fluorido-oxidovanadate(V)

In the structure of the title salt, (C₇H₁₂N₆)[VOF₅], second-order Jahn-Teller distortion of the coordination octa-hedra around V ions is reflected by coexistence of short V-O bonds [1.5767 (12) Å] and trans-positioned long V-F bonds [2.0981 (9) Å], with four equatorial V-F distances being inter-mediate in magnitude [1.7977 (9)-1.8913 (9) Å]. Hydrogen bonding of the anions is restricted to F-atom acceptors only, with particularly strong N-H⋯F inter-actions [N⋯F = 2.5072 (15) Å] established by axial and cis-positioned equatorial F atoms. Hirshfeld surface analysis indicates that the most important inter-actions are overwhelmingly H⋯F/F⋯H, accounting for 74.4 and 36.8% of the contacts for the individual anions and cations, respectively. Weak CH⋯F and CH⋯N bonds are essential for generation of three-dimensional structure.