Synthesis and anti-HSV-1 activity of new 1,2,3-triazole derivatives

New tetrazolopyrrolidine-1,2,3-triazole analogues as potent anticancer agents: design, synthesis and molecular docking studies

1,2,3-Triazole and tetrazole derivatives bearing pyrrolidines are found to exhibit notable biological activity and have become useful scaffolds in medicinal chemistry for application in lead discovery and optimization. We report design, synthesis and molecular docking studies of tetrazolyl-1,2,3-triazole derivatives (7a-i) bearing pyrrolidine moiety and evaluating their anticancer activity against four cancer cell lines viz. Hela, MCF-7, HCT-116 and HepG2. The structures of the new compounds were ascertained by spectral means IR, NMR: 1H &13C and Mass spectrum. From the studies compounds7a and 7i exhibited significant anticancer activity against the Hela cell line with IC50 = 0.32 ± 1.00, 1.80 ± 0.22 μM when compared to reference drug Doxorubicin (IC50 = 2.34 ± 0.11 μM), whereas 7h, 7i, and 7b were found to be active against MCF-7, HCT-116 and HepG2 cell lines with IC50 = 3.20 ± 1.40, 1.38 ± 0.06 and 0.97 ± 0.12 μM respectively. Notably 7a exhibited highest conventional hydrogen bondings TyrA:40, SerA:17, LysA:117, AlaA:146, Tyr218 with 3HB4and SerA:17, LysA:117, AlaA:146, TyrA:40 with 6IBZ and docking energy - 10.85, - 8.21 kcal/mol respectively. These compounds were further evaluated for their ADMET and physicochemical properties by using SwissADME. The results of the in vitro and in silico studies suggest that the tetrazole incorporated pyrrolidine-triazoles may possess the ideal structural requirements for further developing new anticancer agents.

HSV-1 Glycoprotein D and Its Surface Receptors: Evaluation of Protein-Protein Interaction and Targeting by Triazole-Based Compounds through In Silico Approaches

Protein-protein interactions (PPI) represent attractive targets for drug design. Thus, aiming at a deeper insight into the HSV-1 envelope glycoprotein D (gD), protein-protein docking and dynamic simulations of gD-HVEM and gD-Nectin-1 complexes were performed. The most stable complexes and the pivotal key residues useful for gD to anchor human receptors were identified and used as starting points for a structure-based virtual screening on a library of both synthetic and designed 1,2,3-triazole-based compounds. Their binding properties versus gD interface with HVEM and Nectin-1 along with their structure-activity relationships (SARs) were evaluated. Four [1,2,3]triazolo[4,5-b]pyridines were identified as potential HSV-1 gD inhibitors, for their good theoretical affinity towards all conformations of HSV-1 gD. Overall, this study suggests promising basis for the design of new antiviral agents targeting gD as a valuable strategy to prevent viral attachment and penetration into the host cell.

Synthesis of 1,2,3-triazole-thymol derivatives as potential antimicrobial agents

Background

Thymol as a natural biological template can be modified chemically since the hydroxyl group makes it a candidate for structural modification. Thus, this study incorporated the triazole moiety on thymol and the chlorination of thymol moiety to help improve its biological potency.

Materials and methods

A series of ten 1,2,3-triazole-thymol derivatives 1–10 were synthesized from thymol, by a click reaction between O-propargyl terminal alkyne of thymol and its chlorothymol with benzyl azide and substituted benzyl azides. Their structures were confirmed by spectroscopic methods (¹H-NMR, ¹³C-NMR, IR, GC-MS-EI/CI and LC-ESI-QTOF-MS). The Well diffusion method using Müeller-Hinton agar plates was used to demonstrate the antimicrobial activities of the synthesized triazole-thymol derivatives on selected bacterial strains; Escherichia coli ATCC 25922, Staphylococcus aureus ATCC25923, Methicillin resistant S. aureus (MRSA), Pseudomonas aeruginosa ATCC 29853, E. coli ESBL, Klebsiella pneumoniae NCTC 13438 and Meropenem Resistant E. coli.

Results

All the synthesized triazole-thymol derivatives showed significant but variable antibacterial activity against the seven medically important bacterial strains tested. The compound 4-((4-chloro-2-isopropyl-5-methylphenoxy)methyl)-1-(2-nitrobenzyl)-1H-1,2,3triazole (9) demonstrated a higher antibacterial activity with a mean zone of inhibition (38.7 mm) compared with ampicillin as the positive control which gave a zone size of 30.0 mm. In addition, the compound showed a three-fold potency than the parent compound, thymol (11.0 mm) against MRSA at a concentration of 100 μg/ml.

Conclusion

These results provide additional evidence of the exploitation of natural products like thymol as leads for drug development against medically important bacterial pathogens.

Design, Synthesis and Molecular Docking of Novel Acetophenone-1,2,3-Triazoles Containing Compounds as Potent Enoyl-Acyl Carrier Protein Reductase (InhA) Inhibitors

New medications are desperately needed to combat rising drug resistance among tuberculosis (TB) patients. New agents should ideally work through unique targets to avoid being hampered by preexisting clinical resistance to existing treatments. The enoyl-acyl carrier protein reductase InhA of M. tuberculosis is one of the most crucial targets since it is a promising target that has undergone extensive research for anti-tuberculosis drug development. A well-known scaffold for a variety of biological activities, including antitubercular activity, is the molecular linkage of a1,2,3-triazole with an acetamide group. As a result, in the current study, which was aided by ligand-based molecular modeling investigations, 1,2,3-triazolesweredesigned and synthesized adopting the CuAAC aided cycloaddition of 1-(4-(prop-2-yn-1-yloxy)phenyl)ethanone with appropriate acetamide azides. Standard spectroscopic methods were used to characterize the newly synthesized compounds. In vitro testing of the proposed compounds against the InhA enzyme was performed. All the synthesized inhibitors completely inhibited the InhA enzyme at a concentration of 10 µM that exceeded Rifampicin in terms of activity. Compounds 9, 10, and 14 were the most promising InhA inhibitors, with IC₅₀ values of 0.005, 0.008, and 0.002 µM, respectively. To promote antitubercular action and investigate the binding manner of the screened compounds with the target InhA enzyme’s binding site, a molecular docking study was conducted.

Synthesis, Characterization and Nanoformulation of Novel Sulfonamide-1,2,3-triazole Molecular Conjugates as Potent Antiparasitic Agents

Toxoplasma gondii (T. gondii) is a highly prevalent parasite that has no gold standard treatment due to the poor action or the numerous side effects. Focused sulfonamide-1,2,3-triazole hybrids 3a–c were wisely designed and synthesized via copper catalyzed 1,3-dipolar cycloaddition approach between prop-2-yn-1-alcohol 1 and sulfa drug azides 2a–c. The newly synthesized click products were fully characterized using different spectroscopic experiments and were loaded onto chitosan nanoparticles to form novel nanoformulations for further anti-Toxoplasma investigation. The current study proved the anti-Toxoplasma effectiveness of all examined compounds in experimentally infected mice. Relative to sulfadiazine, the synthesized sulfonamide-1,2,3-triazole (3c) nanoformulae demonstrated the most promising result for toxoplasmosis treatment as it resulted in 100% survival, 100% parasite reduction along with the remarkable histopathological improvement in all the studied organs.

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.

Diazocarbonyl and Related Compounds in the Synthesis of Azoles

Diazocarbonyl compounds have found numerous applications in many areas of chemistry. Among the most developed fields of diazo chemistry is the preparation of azoles from diazo compounds. This approach represents a useful alternative to more conventional methods of the synthesis of azoles. A comprehensive review on the preparation of various azoles (oxazoles, thiazoles, imidazoles, pyrazoles, triazoles, and tetrazoles) from diazocarbonyl and related compounds is presented for the first time along with discussion of advantages and disadvantages of «diazo» approaches to azoles.

Bioactive 1,2,3-Triazoles: An Account on their Synthesis, Structural Diversity and Biological Applications

The triazole heterocycle is a privileged scaffold in medicinal chemistry, since its structure is present in a large number of biologically active molecules, including several drugs currently in the market. Due to their vast applications, a wide variety of methods are described for their preparation, such as the 1,3-dipolar cycloaddition and processes involving diazo compounds and diazo transfer reactions. Considering the significant number of contributions from our research group to this chemistry in recent decades, in this account we discuss both the development of new methods for the synthesis of 1,2,3-triazoles and the preparation of new triazole-functionalized biologically active molecules using classical approaches.

Antiviral activity of 1,4-disubstituted-1,2,3-triazoles against HSV-1 in vitro

BACKGROUND

Herpes simplex virus 1 (HSV-1) affects a large part of the adult population. Anti-HSV-1 drugs, such as acyclovir, target thymidine kinase and viral DNA polymerase. However, the emerging of resistance of HSV-1 alerts for the urgency in developing new antivirals with other therapeutic targets. Thus, this study evaluated a series of 1,4-disubstituted-1,2,3-triazole derivatives against HSV-1 acute infection and provided deeper insights into the possible mechanisms of action.

METHODS

Human fibroblast cells (HFL-1) were infected with HSV-1 17syn+ and treated with the triazole compounds at 50 μM for 24 h. The 50% effective drug concentration (EC₅₀) was determined for the active compounds. Their cytotoxicity was also evaluated in HFL-1 with the 50% cytotoxic concentration (CC₅₀) determined using CellTiter-Glo^® solution. The most promising compounds were evaluated by virucidal activity and influence on virus egress, DNA replication and transcription, and effect on an acyclovir-resistant HSV-1 strain.

RESULTS

Compounds 3 ((E)-4-methyl-N'-(2-(4-(phenoxymethyl)-1H-1,2,3-triazol1yl)benzylidene)benzenesulfonohydrazide) and 4 (2,2'-(4,4'-((1,3-phenylenebis(oxy))bis(methylene))bis(1H-1,2,3-triazole-4,1 diyl)) dibenzaldehyde) were the most promising, with an EC₅₀ of 16 and 21 μM and CC₅₀ of 285 and 2,593 μM, respectively. Compound 3 was able to inhibit acyclovir-resistant strain replication and to interfere with virus egress. Both compounds did not affect viral DNA replication, but inhibited significantly the expression of ICP0, ICP4 and gC. Compound 4 also affected the transcription of UL30 and ICP34.5.

CONCLUSIONS

Our findings demonstrated that these compounds are promising antiviral candidates with different mechanisms of action from acyclovir and further studies are merited.

Sofosbuvir Thio-analogues: Synthesis and Antiviral Evaluation of the First Novel Pyridine- and Pyrimidine-Based Thioglycoside Phosphoramidates

The synthesis and antiviral screening of the first reported series of pyridine- and pyrimidine-based thioglycoside phosphoramidates are herein reported. They were prepared through two synthetic steps: The first step is via coupling of mercapto-derivatized heterocyclic bases with the appropriate α-bromo per-acetylated sugars. The second one is the hydrolysis of the acetate esters under basic conditions that were consequently conjugated with the phosphoramidating reagent to afford the desired thioglycoside protides. Eight compounds were evaluated for their antiviral activities against different viral cell lines, namely, adenovirus 7, HAV (hepatitis A) HM175, Coxsackievirus B4, and HSV-1 (herpes simplex virus type 1), in addition to the antiviral bioassay against ED-43/SG-Feo (VYG) replicon of HCV (hepatitis C virus) genotype 4a. Both compounds 5b and 11 showed notable antiviral activity against Coxsackie virus B4, reflected from the CC₅₀ values of 17 and 20 μg/100 μL and IC₅₀ values of 4.5 and 6.0 μg/100 μL, respectively. Same two compounds elicited remarkable activities toward herpes simplex virus type 1, represented by CC₅₀ values of 17 and 16 μg/100 μL and IC₅₀ values of 6.3 and 6.6 μg/100 μL, respectively. Combination of 11 with acyclovir elicited a notable synergistic activity in comparison with acyclovir alone, as inferred from herpes simplex polymerase enzyme inhibitory assay values of 2.64 and 4.78 μg/100 mL, respectively. Only compound 11 elicited a remarkable activity against HCV. Potential promising activities of compound 11 have been shown with respect to CC₅₀, IC₅₀, and enzyme assay inhibitory activities.

Synthesis of 1,4-Biphenyl-triazole Derivatives as Possible 17β-HSD1 Inhibitors: An in Silico Study

Triazoles occupy an important position in medicinal chemistry because of their various biological activities. The structural features of 1,2,3-triazoles enable them to act as a bioisostere of different functional groups such as amide, ester, carboxylic acid, and heterocycle, being capable of forming hydrogen bonds and π-π interactions or coordinate metal ions with biological targets. In this work, the synthesis of 1,2,3-triazole derivatives via copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) is reported. Overexpression of 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1) is often found in breast cancer cells. Molecular similarity and docking analysis were used to evaluate the potential inhibitory activity of 1,2,3-triazoles synthesized over 17β-HSD1 for the treatment of mammary tumors. Our in silico analysis shows that compounds 4c, 4d, 4f, 4g, and 4j are good molecular scaffold candidates as 17β-HSD1 inhibitors.

Neuraminidase from Influenza A and B Viruses is Susceptible to the Compound 4-(4-Phenyl-1H-1,2,3-Triazol-1-yl)-2,2,6,6-Tetramethylpiperidine-1- Oxyl

Background:

Since the influenza virus is the main cause of acute seasonal respiratory infections and pandemic outbreaks, antiviral drugs are critical to mitigate infections and impair chain of transmission. Neuraminidase inhibitors (NAIs) are the main class of anti-influenza drugs in clinical use. Nevertheless, resistance to oseltamivir (OST), the most used NAI, has been detected in circulating strains of the influenza virus. Therefore, novel compounds with anti-influenza activity are necessary.

Objective:

To verify whether the NA from influenza A and B virus is susceptible to the compound 4-(4- phenyl-1H-1,2,3-triazol-1-yl)-2,2,6,6-tetramethylpiperidine-1-oxyl (Tritempo).

Methods:

Cell-free neuraminidase inhibition assays were performed with Tritempo, using wild-type (WT) and OST-resistant influenza strains. Cell-based assays in MDCKs were performed to confirm Tritempo`s antiviral activity and cytotoxicity. Multiple passages of the influenza virus in increasing concentrations of our compound, followed by the sequencing of NA gene and molecular docking, were used to identify our Tritempo’s target.

Results/Discussion:

Indeed, Tritempo inhibited the neuraminidase activity of WT and OSTresistant strains of influenza A and B, at the nanomolar range. Tritempo bound to WT and OST-resistant influenza NA isoforms at the sialic acid binding site with low free binding energies. Cell-free assays were confirmed using a prototypic influenza A infection assay in MDCK cells, in which we found an EC50 of 0.38 µM, along with very low cytotoxicity, CC50 > 2,000 µM. When we passaged the influenza A virus in the presence of Tritempo, a mutant virus with the G248P change in the NA was detected. This mutant was resistant to Tritempo but remained sensitive to OST, indicating no cross-resistance between the studied and reference drugs.

Conclusion:

Our results suggest that Tritempo’s chemical structure is a promising one for the development of novel antivirals against influenza.

Synthesis, Anti-Varicella-Zoster Virus and Anti-Cytomegalovirus Activity of 4,5-Disubstituted 1,2,3-(1H)-Triazoles

BACKGROUND

Clinical drugs for herpesvirus exhibit high toxicity and suffer from significant drug resistance. The development of new, effective, and safe anti-herpesvirus agents with different mechanisms of action is greatly required.

OBJECTIVE

Novel inhibitors against herpesvirus with different mechanisms of action from that of clinical drugs.

METHODS

A series of novel 5-(benzylamino)-1H-1,2,3-triazole-4-carboxamides were efficiently synthesized and EC50 values against Human Cytomegalovirus (HCMV), Varicella-Zoster Virus (VZV) and Herpes Simplex Virus (HSV) were evaluated in vitro.

RESULTS

Some compounds present antiviral activity. Compounds 5s and 5t are potent against both HCMV and VZV. Compounds 5m, 5n, 5s, and 5t show similar EC50 values against both TK+ and TK- VZV strains.

CONCLUSION

5-(Benzylamino)-1H-1, 2,3-triazole-4-carboxamides are active against herpesviruses and their activity is remarkably affected by the nature and the position of substituents in the benzene ring. The results indicate that these derivatives are independent of the viral thymidine kinase (TK) for activation, which is indispensable for current drugs. Their mechanisms of action may differ from those of the clinic anti-herpesvirus drugs.

Exploring the Chemistry and Therapeutic Potential of Triazoles: A Comprehensive Literature Review

:

Triazole is a valuable platform in medicinal chemistry, possessing assorted pharmacological properties, which could play a major role in the common mechanisms associated with various disorders like cancer, infections, inflammation, convulsions, oxidative stress and neurodegeneration. Structural modification of this scaffold could be helpful in the generation of new therapeutically useful agents. Although research endeavors are moving towards the growth of synthetic analogs of triazole, there is still a lot of scope to achieve drug discovery break-through in this area. Upcoming therapeutic prospective of this moiety has captured the attention of medicinal chemists to synthesize novel triazole derivatives. The authors amalgamated the chemistry, synthetic strategies and detailed pharmacological activities of the triazole nucleus in the present review. Information regarding the marketed triazole derivatives has also been incorporated. The objective of the review is to provide insights to designing and synthesizing novel triazole derivatives with advanced and unexplored pharmacological implications.

Design, synthesis, ADME prediction and pharmacological evaluation of novel benzimidazole-1,2,3-triazole-sulfonamide hybrids as antimicrobial and antiproliferative agents

Background

Nitrogen heterocyclic rings and sulfonamides have attracted attention of several researchers.

Results

A series of regioselective imidazole-based mono- and bis-1,4-disubstituted-1,2,3-triazole-sulfonamide conjugates 4a–f and 6a–f were designed and synthesized. The first step in the synthesis was a regioselective propargylation in the presence of the appropriate basic catalyst (Et₃N and/or K₂CO₃) to afford the corresponding mono-2 and bis-propargylated imidazoles 5. Second, the ligation of the terminal C≡C bond of mono-2 and/or bis alkynes 5 to the azide building blocks of sulfa drugs 3a–f using optimized conditions for a Huisgen copper (I)-catalysed 1,3-dipolar cycloaddition reaction yielded targeted 1,2,3-triazole hybrids 4a–f and 6a–f. The newly synthesized compounds were screened for their in vitro antimicrobial and antiproliferative activities. Among the synthesized compounds, compound 6a emerged as the most potent antimicrobial agent with MIC values ranging between 32 and 64 µg/mL. All synthesized molecules were evaluated against three aggressive human cancer cell lines, PC-3, HepG2, and HEK293, and revealed sufficient antiproliferative activities with IC₅₀ values in the micromolar range (55–106 μM). Furthermore, we conducted a receptor-based electrostatic analysis of their electronic, steric and hydrophobic properties, and the results were in good agreement with the experimental results. In silico  ADMET prediction studies also supported the experimental biological results and indicated that all compounds are nonmutagenic and noncarcinogenic.

Conclusion

In summary, we have successfully synthesized novel targeted benzimidazole-1,2,3-triazole-sulfonamide hybrids through 1,3-dipolar cycloaddition reactions between the mono- or bis-alkynes based on imidazole and the appropriate sulfonamide azide under the optimized Cu(I) click conditions. The structures of newly synthesized sulfonamide hybrids were confirmed by means of spectroscopic analysis. All newly synthesized compounds were evaluated for their antimicrobial and antiproliferative activities. Our results showed that the benzimidazole-1,2,3-triazole-sulfonamide hybrids inhibited microbial and fungal strains within MIC values from 32 to 64 μg/mL. The antiproliferative evaluation of the synthesized compounds showed sufficient antiproliferative activities with IC₅₀ values in the micromolar range (55–106 μM). In conclusion, compound 6a has remarkable antimicrobial activity. Pharmacophore elucidation of the compounds was performed based on in silico ADMET evaluation of the tested compounds. Screening results of drug-likeness rules showed that all compounds follow the accepted rules, meet the criteria of drug-likeness and follow Lipinski’s rule of five. In addition, the toxicity results showed that all compounds are nonmutagenic and noncarcinogenic.

Design, synthesis, structural characterization and in vitro evaluation of new 1,4-disubstituted-1,2,3-triazole derivatives against glioblastoma cells

A new series of 1,4-disubstituted-1,2,3-triazole derivatives were synthesized through the copper-catalyzed azide-alkyne 1,3-dipolar cycloaddition (Click chemistry) and their inhibitory activities were evaluated against different human glioblastoma (GBM) cell lines, including highly drug-resistant human cell lines GBM02, GBM95. The most effective compounds were 9d, containing the methylenoxy moiety linked to triazole and the tosyl-hydrazone group, and the symmetrical bis-triazole 10a, also containing methylenoxy moiety linked to triazole. Single crystal X-ray diffraction analysis was employed for structural elucidation of compound 9d. In silico analyses of physicochemical, pharmacokinetic, and toxicological properties suggest that compounds 8a, 8b, 8c, 9d, and 10a are potential candidates for central nervous system-acting drugs.

Hetero-Diels-Alder reactions of novel 3-triazolyl-nitrosoalkenes as an approach to functionalized 1,2,3-triazoles with antibacterial profile

The generation and reactivity of 3-triazolyl-nitrosoalkenes are reported for the first time. The study showed that hetero-Diels-Alder reaction of these heterodienes is an interesting synthetic strategy to functionalized 1,2,3-triazoles, including 1,2,3-triazolyl-pyrroles, 1,2,3-triazolyl-dipyrromethanes and 1,2,3-triazolyl-indoles. The evaluation of the antibacterial profile against Gram-positive and Gram-negative strains revealed the new 5,5'-diethyldipyrromethane bearing a side chain incorporating a triazole and oxime moieties. The antibacterial profile detected was within the Clinical and Laboratory Standard Institute (CLSI) range and against important Staphylococcus species including Methicillin-resistant strain (S. aureus ATCC 25923, S. epidermidis ATCC 12228 and S. simulans ATCC 27851 and MRSA). Interestingly, this new 1,2,3-triazole presented hemocompatibility and low in silico toxicity profile similar to antibiotics current in use. It also has an usual antibiofilm activity against MRSA, which reinforced its potential as a new antibacterial prototype.

Synthesis and the Biological Activity of Phosphonylated 1,2,3-Triazolenaphthalimide Conjugates

A novel series of diethyl {4-[(5-substituted-1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)-methyl]-1H-1,2,3-triazol-1-yl}alkylphosphonates designed as analogues of amonafide was synthesized. All phosphonates were assessed for antiviral activity against a broad range of DNA and RNA viruses and several of them showed potency against varicella-zoster virus (VZV) [EC50 (50% effective concentration) = 27.6-91.5 μM]. Compound 16b exhibited the highest activity against a thymidine kinase-deficient (TK-) VZV strain (EC50 = 27.59 μM), while 16d was the most potent towards TK⁺ VZV (EC50 = 29.91 μM). Cytostatic properties of the compounds 14a-i-17a-i were studied on L1210, CEM, HeLa and HMEC-1 cell lines and most of them were slightly cytostatic for HeLa [IC50 (50% inhibitory concentration) = 29-130 µM] and L1210 cells [IC50 (50% inhibitory concentration) = 14-142 µM].

An efficient, green synthesis of novel regioselective and stereoselective indan-1,3-dione grafted spirooxindolopyrrolizidine linked 1,2,3-triazoles via a one-pot five-component condensation using PEG-400

An efficient synthesis of highly diversified novel functionalized indan-1,3-dione grafted spirooxindolopyrrolizidine linked 1,2,3-triazole conjugates is reported using Cu(i) as a catalyst in PEG-400.

Reaction of Nitrilimines with Pyruvaldehyde Hydrazones: Synthesis and Antimicrobial Evaluation of Some New 1,2,4-Triazole Derivatives

A new series of 1,3,4,5,5-pentasubstituted-1,2,4-triazoles (4a–j,6a–j) have been synthesized by the 1,3-dipolar cycloaddition of suitable nitrilimines2to pyruvaldehyde (2-oxopropanal) hydrazones having (COPh, COOMe, COOEt, Me/Me, and Me/Ph) groups3and5. Both analytical and spectroscopical data of all the synthesized compounds are in full agreement with the proposed structures. The microbial features of the synthesized compounds were studied by a known method.

Synthesis and antifungal activity of benzamidine derivatives carrying 1,2,3-triazole moieties

Eighteen novel benzamidine derivatives containing 1,2,3-triazole moieties were synthesized. The in vitro and in vivo fungicidal acitivities of the title compounds and the arylamidine intermediates against Colletotrichum lagenarium and Botrytis cinerea were tested. The synthesized benzamidines exhibited weak antifungal activities in vitro against the tested fungi, but some of the compounds showed excellent activities in vivo to the same strains. Among the compounds tested, 9b showed 79% efficacy in vivo against C. lagenarium at a concentration of 200 μg/mL, and the efficacy of compound 16d (90%) toward the same strain was even superior than that of the commercial fungicide carbendazim (85%).

Design, synthesis, antiviral and cytotoxic evaluation of novel acyclic phosphonate nucleotide analogues with a 5,6-dihydro-1H-[1,2,3]triazolo[4,5-d]pyridazine-4,7-dione system

ABSTRACT

A series of diethyl 2-(4,5-dimethoxycarbonyl-1H-1,2,3-triazol-1-yl)alkylphosphonates was synthesised from ω-azidoalkylphosphonates and dimethyl acetylenedicarboxylate and was further transformed into the respective diamides, dihydrazides, and 5,6-dihydro-1H-[1,2,3]triazolo[4,5-d]pyridazine-4,7-diones as phosphonate analogues of acyclic nucleosides having nucleobases replaced with substituted 1,2,3-triazoles. All compounds containing P-C-C-triazole or P-C-C-CH2-triazole moieties exist in single conformations in which the diethoxyphosphoryl and substituted 1,2,3-triazolyl or substituted (1,2,3-triazolyl)methyl groups are oriented anti. All phosphonates were evaluated in vitro for activity against a variety of DNA and RNA viruses. None of the compounds were endowed with antiviral activity. They were not cytostatic at 100 μM.

GRAPHICAL ABSTRACT

1-Phenyl-1H- and 2-phenyl-2H-1,2,3-triazol derivatives: design, synthesis and inhibitory effect on alpha-glycosidases

Due to aging and increasingly overweight in human population, the incidence of non-insulin dependent diabetes mellitus (NIDDM or Type 2 DM) is increasing considerably. Therefore, searching for new α-glycosidase inhibitors (GIs) capable of slowing down carbohydrate assimilation by humans is an important strategy towards control of NIDDM. In this report, we disclose the search for new easily accessible synthetic triazoles as anti-diabetic compounds. Two series of non-glycosid triazoles were synthesized (series A and B) and screened against baker's yeast α-glucosidase (MAL12) and porcine pancreatic α-amylase activity (PPA). Of the 60 compounds tested at 500 μM, were considered hits (≥60% inhibition) six triazoles against MAL12 and three against PPA, with the inhibition reaching up to 99.4% on MAL12 and 88.6% on PPA. The IC₅₀ values were calculated for both enzymes and ranged from 54 to 482 μM for MAL12 and 145 to 282 μM for PPA. These results demonstrated the potential activity of simple and non-glycosidic triazoles as an important novel class of GIs for the development of drugs to treat Type 2 DM.

Synthesis, characterization, X-ray structure and biological activities of C-5-bromo-2-hydroxyphenylcalix[4]-2-methyl resorcinarene

C-5-bromo-2-hydroxyphenylcalix[4]-2-methylresorcinarene (I) was synthesized by cyclocondensation of 5-bromo-2-hydroxybenzaldehyde and 2-methylresorcinol in the presence of concentrated HCl. Compound I was characterized by infrared and nuclear magnetic resonance spectroscopic data. X-ray analysis showed that this compound crystallized in a triclinic system with space group of Pī, a = 15.9592(16)Å, b = 16.9417(17)Å, c = 17.0974(17)Å, α = 68.656(3)°, β = 85.689(3)°, γ = 81.631(3)°, Z = 2 and V = 4258.6(7)ų. The molecule adopts a chair (C_2h) conformation. The thermal properties and antioxidant activity were also investigated. It was strongly antiviral against HSV-1 and weakly antibacterial against Gram-positive bacteria. Cytotoxicity testing on Vero cells showed that it is non-toxic, with a CC₅₀ of more than 0.4 mg/mL.

Antivenom effects of 1,2,3-triazoles against Bothrops jararaca and Lachesis muta snakes

Snake venoms are complex mixtures of proteins of both enzymes and nonenzymes, which are responsible for producing several biological effects. Human envenomation by snake bites particularly those of the viperid family induces a complex pathophysiological picture characterized by spectacular changes in hemostasis and frequently hemorrhage is also seen. The present work reports the ability of six of a series of 1,2,3-triazole derivatives to inhibit some pharmacological effects caused by the venoms of Bothrops jararaca and Lachesis muta. In vitro assays showed that these compounds were impaired in a concentration-dependent manner, the fibrinogen or plasma clotting, hemolysis, and proteolysis produced by both venoms. Moreover, these compounds inhibited biological effects in vivo as well. Mice treated with these compounds were fully protected from hemorrhagic lesions caused by such venoms. But, only the B. jararaca edema-inducing activity was neutralized by the triazoles. So the inhibitory effect of triazoles derivatives against some in vitro and in vivo biological assays of snake venoms points to promising aspects that may indicate them as molecular models to improve the production of effective antivenom or to complement antivenom neutralization, especially the local pathological effects, which are partially neutralized by antivenoms.

5-Methyl-N′-[(3Z)-2-oxo-2,3-dihydro-1H-indol-3-ylidene]-1-phenyl-1H-1,2,3-triazole-4-carbohydrazide

In the title compound, C₁₈H₁₄N₆O₂, the benzene ring is slightly twisted out of the plane of the 1,2,3-triazole ring (r.m.s. deviation = 0.010 Å), forming a dihedral angle of 6.20 (13)°. The nine non-H ring atoms of the fused five- and six-membered ring system are almost coplanar (r.m.s. deviation = 0.032 Å). The near coplanarity in the central residue is consolidated by an intra­molecular bifurcated N—H⋯(O,N) hydrogen bond. The conformation about the N=C bond is Z. In the crystal, supra­molecular chains along [101] are sustained by N—H⋯O hydrogen bonds and C—H⋯O inter­actions. These are consolidated into a three-dimensional architecture by C—H⋯π and π–π inter­actions; the latter occur between centrosymmetrically related 1,2,3-triazole rings [centroid–centroid distance = 3.6056 (14) Å].

A Facile Eco-Friendly One-Pot Five-Component Synthesis of Novel 1,2,3-Triazole-Linked Pentasubstituted 1,4-Dihydropyridines and their Biological and Photophysical Studies

An eco-friendly one-pot five-component synthesis of novel 1,2,3-triazole-linked pentasubstituted 1,4-dihydropyridines under ultrasonic and microwave irradiation in polyethylene glycol (PEG) 400 is described. All newly synthesised compounds were evaluated for antibacterial activity, antifungal activity, antioxidant activity, and photophysical properties. Antimicrobial activity was evaluated against six microbial strains. All compounds exhibited antifungal activity against Aspergillus niger and Aspergillus flavus and moderate antibacterial activity against Gram positive bacteria (Staphylococcus aureus and Bacillus subtilis). Antioxidant activity was evaluated using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay. All compounds showed good to moderate antioxidant activity. Furthermore all new compounds showed strong fluorescence in solution.