Antifungal activity, SAR and physicochemical correlation of some thiazole-1,3,5-triazine derivatives

Design, in silico study, synthesis and evaluation of hybrid pyrazole substituted 1,3,5-triazine derivatives for antimalarial activity

OBJECTIVES

Malaria is a significant global health challenge, particularly in Africa, Asia, and Latin America, necessitating immediate investigation into innovative and efficacious treatments. This work involves the development of pyrazole substituted 1,3,5-triazine derivatives as antimalarial agent.

METHODS

In this study, ten compounds 7(a-j) were synthesized by using nucleophilic substitution reaction, screened for in silico study and their antimalarial activity were evaluated against 3D7 (chloroquine-sensitive) strain of P. falciparum.

KEY FINDING

The present work involves the development of hybrid trimethoxy pyrazole 1,3,5-triazine derivatives 7 (a-j). Through in silico analysis, four compounds were identified with favorable binding energy and dock scores. The primary focus of the docking investigations was on the examination of hydrogen bonding and the associated interactions with certain amino acid residues, including Arg A122, Ser A108, Ser A111, Ile A164, Asp A54, and Cys A15. The IC50 values of the four compounds were measured in vitro to assess their antimalarial activity against the chloroquine sensitive 3D7 strain of P. falciparum. The IC50 values varied from 25.02 to 54.82 μg/mL.

CONCLUSION

Among the ten derivatives, compound 7J has considerable potential as an antimalarial agent, making it a viable contender for further refinement in the realm of pharmaceutical exploration, with the aim of mitigating the global malaria load.

Synthesis and molecular docking studies of new aryl imeglimin derivatives as a potent antidiabetic agent in a diabetic zebrafish model

Diabetes mellitus (DM) is a persistent, progressive, and multifaceted disease characterized by elevated blood glucose levels. Type 2 diabetes mellitus is associated with a relative deficit in insulin mainly due to beta cell dysfunction and peripheral insulin resistance. Metformin has been widely prescribed as a primary treatment option to address this condition. On the other hand, an emerging glucose-reducing agent known as imeglimin has garnered attention due to its similarity to metformin in terms of chemical structure. In this study, an innovative series of imeglimin derivatives, labeled 3(a-j), were synthesized through a one-step reaction involving an aldehyde and metformin. The chemical structures of these derivatives were thoroughly characterized using ESI-MS, 1H, and 13C NMR spectroscopy. In vivo tests on a zebrafish diabetic model were used to evaluate the efficacy of the synthesized compounds. All compounds 3(a-j) showed significant antidiabetic effects. It is worth mentioning that compounds 3b (FBS = 72.3 ± 7.2 mg/dL) and 3g (FBS = 72.7 ± 4.3 mg/dL) have antidiabetic effects comparable to those of the standard drugs metformin (FBS = 74.0 ± 5.1 mg/dL) and imeglimin (82.3 ± 5.2 mg/dL). In addition, a docking study was performed to predict the possible interactions between the synthesized compounds and both SIRT1 and GSK-3β targets. The docking results were in good agreement with the experimental assay results.

Novel synthesis of new triazine sulfonamides with antitumor, anti-microbial and anti-SARS-CoV-2 activities

Novel approach for synthesizing triazine sulfonamide derivatives is accomplished via reacting the sulfaguanidine derivatives with N-cyanodithioiminocarbonate. Further reaction of the novel triazine sulfonamide analogues with various secondary amines and anilines generated various substituted triazine sulfonamide analogues of promising broad-spectrum activities including anti-microbial, anti-tumor, and anti-viral properties. The in vitro anti-proliferative activities of most of the novel compounds were evaluated on the NCI-60 cell line panel. The antifungal and antibacterial activities of the compounds were also estimated. The anti-viral activity against SARS CoV-2 virus was performed using MTT cytotoxicity assay to evaluate the half-maximal cytotoxic concentration (CC50) and inhibitory concentration 50 (IC50) of a representative compound from the novel triazine sulfonamide category. Compound 3a demonstrated potent antiviral activity against SARS-CoV-2 with IC50 = 2.378 µM as compared to the activity of the antiviral drug remdesivir (IC50 = 10.11 µM). Our results indicate that, upon optimization, these new triazine sulfonamides could potentially serve as novel antiviral drugs.

Discovery of Lead 2-Thiazolylhydrazones with Broad-Spectrum and Potent Antifungal Activity

Opportunistic fungal infections represent a global health problem, mainly for immunocompromised individuals. New therapeutical options are needed since several fungal strains show resistance to clinically available antifungal agents. 2-Thiazolylhydrazones are well-known as potent compounds against Candida and Cryptococcus species. A scaffold-focused drug design using machine-learning models was established to optimize the 2-thiazolylhydrazone skeleton and obtain novel compounds with higher potency, better solubility in water, and enhanced absorption. Twenty-nine novel compounds were obtained and most showed low micromolar MIC values against different species of Candida and Cryptococcus spp., including Candida auris, an emerging multidrug-resistant yeast. Among the synthesized compounds, 2-thiazolylhydrazone 28 (MIC value ranging from 0.8 to 52.17 μM) was selected for further studies: cytotoxicity evaluation, permeability study in Caco-2 cell model, and in vivo efficacy against Cryptococcus neoformans in an invertebrate infection model. All results obtained indicate the great potential of 28 as a novel antifungal agent.

Exploration and Evaluation of Secondary Metabolites from Trichoderma harzianum: GC-MS Analysis, Phytochemical Profiling, Antifungal and Antioxidant Activity Assessment

In this study, we investigated in vitro the potential of Trichoderma harzianum to produce bioactive secondary metabolites that can be used as alternatives to synthetic compounds. The study focused on analyzing two extracts of T. harzianum using ethyl acetate and n-butanol solvents with different polarities. The extracts were examined using phytochemical analysis to determine the content of polyphenols, flavonoids, tannins, and alkaloids. Thin-layer chromatography (TLC) and Gas chromatography-mass spectroscopy (GC-MS) analysis were used to profile volatile organic metabolites (VOCs) present in the extracts. Furthermore, the extracts were tested for their antifungal ability using the poison food technique. For measuring antioxidant activity, the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) test was used. Trichoderma harzianum was shown to have a significantly high content of tannins and alkaloids, with a noticeable difference between the two extracts. GC-MS analysis identified 33 potential compounds with numerous benefits that could be used in agriculture and the medicinal industry. Moreover, strong antifungal activity was identified against Sclerotinia sclerotiorum by 94.44%, Alternaria sp. by 77.04%, and Fusarium solani by 51.48; similarly, the IC₅₀ of antioxidant activity was estimated for ethyl acetate extract by 71.47% and n-butanol extract by 56.01%. This leads to the conclusion that Trichoderma harzianum VOCs play a significant role as an antifungal and antioxidant agent when taking into account the advantageous bioactive chemicals noted in the extracts. However, to our knowledge, this is the first study in Algeria presenting detailed phytochemical analysis and GC-MS profiling of Trichoderma harzianum for two extracts, ethyl acetate and n-butanol.

Membrane-active substituted triazines as antibacterial agents against Staphylococcus aureus with potential for low drug resistance and broad activity

A library of new naphthalimide-triazine analogues was synthesized as broad-spectrum antibacterial agents to overcome drug resistance. Bioactivity assay reveals that derivative 8e, with benzylamine in its structure, exhibits strong antibacterial properties against multi-drug resistance Staphylococcus aureus at a concentration of 1.56 μg/ml. It was also found to be better than chloromycin and amoxicillin. The active compound 8e efficiently inhibits the development of drug resistance within 11 passages. In addition, compound 8e inhibits the formation of biofilms in S. aureus and acts rapidly in bactericidal efficacy. Furthermore, mechanistic studies reveal that compound 8e effectively destroys the cytoplasmic membrane of bacteria, leading to leakage of intercellular protein content and loss in metabolic activity. Compound 8e binds to HSA readily with a binding constant of 1.32 × 10⁵ M^-1, indicating that the compound could be delivered to the target site effectively. Compound 8e can also form a supramolecular complex with DNA to obstruct DNA replications. These results suggest that analogue 8e could be further developed as a potential antibacterial agent. Furthermore, the cytotoxicity of all the synthesized compounds was evaluated against 60 human cancer cell lines to test their potential for anticancer agents.

Molecular docking and antimalarial evaluation of hybrid para-aminobenzoic acid 1,3,5 triazine derivatives via inhibition of Pf-DHFR

In this study, a structurally guided pharmacophore hybridization strategy is used to combine the two key structural scaffolds, para-aminobenzoic acid (PABA), and 1,3,5 triazine in search of new series of antimalarial agents. A combinatorial library of 100 compounds was prepared in five different series as [4A (1-22), 4B (1-21), 4 C (1-20), 4D (1-19) and 4E (1-18)] using different primary and secondary amines, from where 10 compounds were finally screened out through molecular property filter analysis and molecular docking study as promising PABA substituted 1,3,5-triazine scaffold as an antimalarial agent. The docking results showed that compounds 4A12 and 4A20 exhibited good binding interaction with Phe58, IIe164, Ser111, Arg122, Asp54 (-424.19 to -360.34 kcal/mol) and Arg122, Phe116, Ser111, Phe58 (-506.29 to -431.75 kcal/mol) against wild (1J3I) and quadruple mutant (1J3K) type of Pf-DHFR. These compounds were synthesized by conventional as well as microwave-assisted synthesis and characterized by different spectroscopic methods. In-vitro antimalarial activity results indicated that two compounds 4A12 and 4A20 showed promising antimalarial activity against chloroquine-sensitive (3D7) and chloroquine-resistant (Dd2) strains of Plasmodium falciparum with IC50 (1.24-4.77 μg mL-1) and (2.11-3.60 μg mL-1). These hybrid PABA substituted 1,3,5-triazine derivatives might be used in the lead discovery towards a new class of Pf-DHFR inhibitors.Communicated by Ramaswamy H. Sarma.

Chimeric Tobramycin-Based Adjuvant TOB-TOB-CIP Potentiates Fluoroquinolone and β-Lactam Antibiotics against Multidrug-Resistant Pseudomonas aeruginosa

According to the World Health Organization, antibiotic resistance is a global health threat. Of particular importance are infections caused by multidrug-resistant Gram-negative bacteria including Escherichia coli, Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa for which limited treatment options exist. Multiple and simultaneously occurring resistance mechanisms including outer membrane impermeability, overexpression of efflux pumps, antibiotic-modifying enzymes, and modification of genes and antibiotic targets have made antibiotic drug development more difficult against these pathogens. One strategy to cope with these challenges is the use of outer membrane permeabilizers that increase the intracellular concentration of antibiotics when used in combination. In some circumstances, this approach can rescue antibiotics from resistance or repurpose currently marketed antibiotics. Tobramycin-based hybrid antibiotic adjuvants that combine two outer membrane-active components have been previously shown to potentiate antibiotics by facilitating transit through the outer membrane, resulting in increased antibiotic accumulation within the cell. Herein, we extended the concept of tobramycin-based hybrid antibiotic adjuvants to tobramycin-based chimeras by engineering up to three different membrane-active antibiotic warheads such as tobramycin, 1-(1-naphthylmethyl)-piperazine, ciprofloxacin, and cyclam into a central 1,3,5-triazine scaffold. Chimera 4 (TOB-TOB-CIP) consistently synergized with ciprofloxacin, levofloxacin, and moxifloxacin against wild-type and fluoroquinolone-resistant P. aeruginosa. Moreover, the susceptibility breakpoints of ceftazidime, aztreonam, and imipenem were reached using the triple combination of chimera 4 with ceftazidime/avibactam, aztreonam/avibactam, and imipenem/relebactam, respectively, against β-lactamase-harboring P. aeruginosa. Our findings demonstrate that tobramycin-based chimeras form a novel class of antibiotic potentiators capable of restoring the activity of antibiotics against P. aeruginosa.

Discovery of novel 1,3,5-triazines as potent antibacterial agent against urinary tract infection-causing clinical isolates of Escherichia coli via inhibition of DNA Gyrase

A novel series of 1,3,5-triazine-phenylthiazole-pyrazole derivatives were synthesized and subsequently tested for Escherichia coli DNA Gyrase inhibitory activity where they showed excellent inhibitory activity. The top-three ranked DNA gyrase inhibitor (4e, 4g and 4h) were further subjected to antibacterial and anti-biofilm activity against clinical isolates of resistant E. coli strains obtained from Urinary Tract Infection (UTI) patients (CREC81, CREC106, CREC163). Compound 4h was identified as most potent antibacterial agent in the above study. The compound 4h was further evaluated in murine model of E. coli UTI in BALB/c mice infected by transurethral injection of CREC106 strain. Results of the study suggest that compound 4h reduces bacterial load of CREC106 in the treated mice and found approximately equipotent to Novobiocin as standard.

Triazine-Based Small Molecules: A Potential New Class of Compounds in the Antifungal Toolbox

Invasive fungal infections caused by Candida species remain a significant public health problem worldwide. The increasing prevalence of drug-resistant infections and a limited arsenal of antifungal drugs underscore the need for novel interventions. Here, we screened several classes of pharmacologically active compounds against mammalian diseases for antifungal activity. We found that the synthetic triazine-based compound melanogenin (Mel) 56 is fungicidal in Candida albicans laboratory and clinical strains with minimal inhibitory concentrations of 8−16 µg/mL. Furthermore, Mel56 has general antifungal activity in several non-albicans Candida species and the non-pathogenic yeast Saccharomyces cerevisiae. Surprisingly, Mel56 inhibited the yeast-to-hyphae transition at sublethal concentrations, revealing a new role for triazine-based compounds in fungi. In human cancer cell lines, Mel56 targets the inner mitochondrial integral membrane prohibitin proteins, PHB1 and PHB2. However, Mel56 treatment did not impact C. albicans mitochondrial activity, and antifungal activity was similar in prohibitin single, double, and triple homozygous mutant strains compared to the wild-type parental strain. These results suggests that Mel56 has a novel mechanism-of-action in C. albicans. Therefore, Mel56 is a promising antifungal candidate warranting further analyses.

Molecular docking and antimalarial evaluation of novel N-(4-aminobenzoyl)-l-glutamic acid conjugated 1,3,5-triazine derivatives as Pf-DHFR inhibitors

Malaria has been a source of concern for humans for millennia; therefore in the present study we have utilized in-silico approach to generate diverse anti-malarial hit. Towards this, Molinspiration cheminformatics and Biovia Discovery Studio (DS) 2020 were used to conduct molecular modelling studies on 120 designed compounds. Furthermore, the TOPKAT module was used to evaluate the toxicity of the screened compounds. The CDOCKER docking technology was used to investigate protein-ligand docking against the Pf-DHFR-TS protein (PDB ID: 1J3I and 1J3K). These compounds were synthesized using a conventional and microwave-assisted nucleophilic substitution reaction, and they were characterized using a variety of physicochemical and spectroscopic methods. Among the ten compounds tested, Df3 had the highest antimalarial activity against the chloroquine-resistant (Dd2) strain, with an IC50 value of 9.54 μg mL-1 and further demonstrate, molecular dynamics (MD) simulation studies and estimation of MM-PBSA-based free binding energies of docked complexes with 1J3I and 1J3K were carried out. The discovery of a novel class of Pf-DHFR inhibitors can be accomplished using this hybrid scaffold.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03400-2.

Discovery of Novel Thiosemicarbazides Containing 1,3,5-Triazines Derivatives as Potential Synergists against Fluconazole-Resistant Candida albicans

The clinical prevalence of antifungal drug resistance has been increasing over recent years, resulting in the failure of treatments. In an attempt to overcome this critical problem, we sought novel synergistic enhancers to restore the effectiveness of fluconazole against resistant Candida albicans. Based on the structural optimization of hit compound 8 from our in-house library, a series of novel 1,3,5-triazines derivatives was designed, synthesized, and biologically evaluated for synergistic activity in combination with fluconazole. Among them, compounds 10a-o, which contain thiosemicarbazides side chains, exhibited excellent in vitro synergistic antifungal potency (MIC80 = 0.125-2.0 μg/mL, FICI range from 0.127 to 0.25). Interestingly, compound 10l exhibited moderate C. albicans activity as monotherapy with an MIC80 value of 4.0 μg/mL, and also on several Cryptococcus strains (MIC80 ranging from ≤ 0.125-0.5 μg/mL) and C. glabrata (MIC80 ≤ 0.125 μg/mL). These effects were fungal-selective, with much lower levels of cytotoxicity towards human umbilical vein endothelial cells. Here, we report a series of thiosemicarbazides containing 1,3,5-triazines derivatives as potent synergists with fluconazole, and have preliminarily validated compound 10l as a promising antifungal lead for further investigation.

Structure-Activity Design, Synthesis and Biological Activity of Newer Imidazole- Triazine Clubbed Derivatives as Antimicrobial and Antitubercular Agents

Background:

Imidazole and triazine derivatives act as antimicrobial and antitubercular agents. 2D-QSAR determination estimates the pharmacological activity based on the thermodynamic properties of the structure.

Objective:

The structural arrangements and thermodynamic properties of the imidazole derivatives are necessary for the enhancement of pharmacological activity. So,imidazole-triazine clubbed derivatives were designed based on molecular modeling 2D-QSAR study on antitubercular activity.

Methods:

PLSR method is applied for 2D-QSAR determination of the (Z)-5-ethylidene-3-(4- methoxy-6-methyl-1,3,5-triazin-2-yl)-2-phenyl-3,5-dihydro-4H-imidazol-4-one (B1-B10). The designed compounds were synthesized and spectrally evicted by IR, 1H NMR, 13C NMR, and mass spectra data as well as biologically screened against the different antitubercular and antimicrobial species.

Result:

Compounds B4, B6, and B7 were found potent against the different antimicrobial species. Compound B3 was more effective against the M. tuberculosis H37Rv. Statistically significant QSAR model generated by PLSR methods showed external r2=0.9775 and internal q2=0.2798 predictive abilities. Furthermore, the model also incorporated three parameters, Polar Surface Area Excluding Pand S, Mom Inertia Y, and SsCH3 count, with their corresponding values for each molecule.

Conclusion:

The 2D-QSAR study revealed that antitubercular activity was directly proportional to the total surface area of the polar atoms having molecules and the moment of inertia on the Y-axis. At the same time, antitubercular activity was inversely proportional to the methyl group joined with a single bond. The present study afforded favorable results, which were further used to generate lead target molecules.

Synthesis, combined theoretical and spectral characterization of some new 1,3,5 triazine compounds, and their in vitro biological analysis

New N-heterocyclic compounds with a 1,3,5 triazine core were synthesized by a nucleophilic substitution reaction.

Synthesis, and Molecular Structure Investigations of a New s-Triazine Derivatives Incorporating Pyrazole/Piperidine/Aniline Moieties

In this work, we synthesized two new s-triazine incorporates pyrazole/piperidine/aniline moieties. Molecular structure investigations in the light of X-ray crystallography combined with Hirshfeld and DFT calculations were presented. Intermolecular interactions controlling the molecular packing of 4-(3,5-dimethyl-1H-pyrazol-1-yl)-N-phenyl-6-(piperidin-1-yl)-1,3,5-triazin-2-amine; 5a and N-(4-bromophenyl)-4-(3,5-dimethyl-1H-pyrazol-1-yl)-6-(piperidin-1-yl)-1,3,5-triazin-2-amine; 5b were analyzed using Hirshfeld calculations. The most dominant interactions are the H...H, N...H and H...C contacts in both compounds. The N...H and H...C interactions in 5a and the N...H, Br...H and H...H interactions in 5b are the most important. In addition, DFT calculations were used to compute the molecular structures of 5a and 5b; then, their electronic properties, as well as the 1H- and 13C-NMR spectra, were predicted. Both compounds are polar where 5a (1.018 Debye) has lower dipole moment than 5b (4.249 Debye). The NMR chemical shifts were calculated and very good correlations between the calculated and experimental data were obtained (R2 = 0.938–0.997).

Design and development of novel fasudil derivatives as potent antibreast cancer agent that improves intestinal flora and intestinal barrier function in rats

This study was conducted to develop novel fasudil derivatives after incorporation of substituted thiazoles as potent anti-breast cancer (BC) agents. The compounds were developed using a facile synthetic route in excellent yields. The entire set of developed compounds was tested for inhibitory activity against rho-associated coiled-coil kinase (ROCK; ROCK1 and ROCK2) kinase, where they exhibit potent and selective inhibition of ROCK1 as compared to ROCK2. The most potent ROCK2 inhibitor, compound 6h significantly inhibited the viability of BC cells (MCF-7). It also causes inhibition of migration and invasion of MCF-7 cells. Moreover, the anti-BC activity of compound 6h was studied in 7,12 dimethyl Benz(a)anthracene (DMBA)-induced BC in female Sprague Dawley rats. Results suggest that it causes significant improvement in the bodyweight of the animals with a reduction in oxidative stress in the liver and mammary tissues of rats. It showed improvement in the intestinal barrier function of rats by restoring the level of Diamine oxidase, d-lactate, and endotoxin. In western blot analysis, it showed improvement in (ZO-1), occludin, and claudin-1 in the colon tissue of the rat as compared to the DMBA group. Our study demonstrated the development of the novel class of fasudil derivatives potent anti-BC agent that improves intestinal flora and intestinal barrier function in rats.

Novel 1,3,5-triazine-nicotinohydrazide derivatives induce cell arrest and apoptosis in osteosarcoma cancer cells and inhibit osteosarcoma in a patient-derived orthotopic xenograft mouse model

The present study deals with developing novel 1,3,5-triazine-nicotinohydrazide derivatives as potent CDK9 inhibitors in a straightforward synthetic route with potent anti-osteosarcoma activity. The most potent CDK9 inhibitor compound 5k inhibits proliferation of MG-63 cells via induction of apoptosis and G2/M cell cycle arrest. It reduces tumor progression in the patient-derived orthotopic xenograft (PDOX) mouse model with significant antioxidant and anti-inflammatory activity. In tumor tissue homogenates, it caused significant inhibition of CDK9 and inhibited the phosphorylation of RNAPII ser2 and reduced MCL-1 expression in Western blot analysis. Compound 5k also showed considerable bioavailability in SD mice. Our results demonstrated that compound 5k inhibits growth of OS in vitro and in vivo via inhibition of CDK9 which attenuated the downstream phosphorylation of RNAPII ser2 and represses expression of the anti-apoptotic protein, MCL-1 for the induction of apoptosis in OS.

Microwave-assisted synthesis of hybrid PABA-1,3,5-triazine derivatives as an antimalarial agent

The present manuscript deals with the development of novel p-aminobenzoic acid (PABA) associated 1,3,5-triazine derivatives as antimalarial agents. The molecules were developed via microwave-assisted synthesis and structures of compounds were ascertained via numerous analytical and spectroscopic techniques. The synthesized compounds were also subjected to ADMET analysis. In a docking analysis, the title compounds showed high and diverse binding affinities towards wild (-162.45 to -369.38 kcal/mol) and quadruple mutant (-165.36 to -209.47 kcal/mol) Pf-DHFR-TS via interacting with Phe58, Arg59, Ser111, Ile112, Phe116. The in vitro antimalarial activity suggested that compounds 4e, 4b, and 4h showed IC₅₀ ranging from 4.18 to 8.66 μg/ml against the chloroquine-sensitive (3D7) strain of Plasmodium falciparum. Moreover, compounds 4g, 4b, 4e, and 4c showed IC₅₀ ranging from 8.12 to 12.09 μg/ml against chloroquine-resistant (Dd2) strain. In conclusion, our study demonstrated the development of hybrid PABA substituted 1,3,5-triazines as a novel class of Pf-DHFR inhibitor for antimalarial drug discovery.

MM-129 as a Novel Inhibitor Targeting PI3K/AKT/mTOR and PD-L1 in Colorectal Cancer

Simple Summary

MM-129 (1,2,4-triazine derivative) is a novel promising drug candidate against colon cancer. It has the ability to inhibit intracellular pathways promoting tumorigenesis with a simultaneous reduction of PD-L1 expression, a key element of the cancer immune escape axis. MM-129 may also act as a chemosensitizer, overcoming chemoresistance against 5-FU, the first-line agent in the chemother-apy of colon cancer. Our results significantly expand knowledge and help better understand the process of tumorigenesis, the intracellular pathways involved, and the mutual interactions of in-dividual proteins, and create the possibility of their pharmacological blockade. There is a real chance that the obtained results and the conclusions drawn on their basis will help in the development of a new, effective therapy, which could be an attractive alternative to the already existing methods of colon cancer treatment.

Abstract

Background and aims: The purpose of the present study was to examine the pharmacodynamics features of MM-129 (1,2,4-triazine derivative) as a novel promising drug candidate against colon cancer. Methods: MM-129 was assessed for antitumor activity through an in vivo study on Cby.Cg-Foxn1nu/cmdb mice. The mechanistic studies investigated cellular affinity of a new 1,2,4-triazine derivative by measuring levels of intracellular/extracellular signal molecules participating in tumorigenesis. Results: The results revealed that MM-129 significantly reduced tumor growth in mice challenged with DLD-1 and HT-29 cells. It exerted the ability to inhibit intracellular molecules promoting tumorigenesis and inducing cell cycle arrest, like Akt, mTOR, and CDK2. Simultaneously, it was able to downregulate PD-L1 expression, which involves immunological self-tolerance. Combined administration of MM-129 and 5-fluorouracil (5-FU) additionally amplified these effects, which were manifest as an increase population of cells in the G0/G1 phase. Conclusions: A novel 1,2,4-triazine derivative with a dual mechanism of antitumor activity—MM-129, may act as a chemosensitizer, overcoming chemoresistance against 5-FU, the first-line agent in the chemotherapy of colon cancer.

1,3,5-Triazine: A versatile pharmacophore with diverse biological activities

1,3,5-Triazine and its derivatives have been the epicenter of chemotherapeutic molecules due to their effective biological activities, such as antibacterial, fungicidal, antimalarial, anticancer, antiviral, antimicrobial, anti-inflammatory, antiamoebic, and antitubercular activities. The present review represents a summarized report of the crucial biological activities possessed by substituted 1,3,5-triazine derivatives, with special attention to the most potent compounds.

Design and development of 1,3,5-triazine derivatives as protective agent against spinal cord injury in rat via inhibition of NF-ĸB

Spinal cord injury (SCI) is a chronic disease causing motor and sensory loss in the affected individuals. The SCI has a huge impact on the lives of patients that makes them susceptible to life-long disability. However, the current clinical modalities are ineffective to cope the aftermath of SCI. Thus, in the present study, we aimed to develop a series of 1,3,5-triazine derivatives as a protective agent against SCI. The molecules were developed by facile synthetic route and obtained in excellent yield. The compounds were tested for their efficacy to inhibit the transcription of NF-κB in RAW 264.7 cells, where they displayed mild to potent activity. Compound 8a was identified as most potent NF-κB inhibitor among the tested analogues. The effect of compound 8a was further scrutinized against the SCI injury in rats induced by contusion injury. It has been found that compound 8a improves motor function of rats together with reduction in inflammation and edema in spinal cord of rats. It also showed to inhibit oxidative stress and inflammation in the SCI rats. In a western blot analysis, after SCI induction, compound 8a inhibited NF-κB and its upstream regulator TLR4 in a dose-dependent manner. Collectively, our study provides a novel class of agent that provide protective action against SCI.

In silico study, synthesis, and evaluation of the antimalarial activity of hybrid dimethoxy pyrazole 1,3,5-triazine derivatives

Malaria continues to become a major global health problem, particularly in Sub-Saharan Africa, Asia, and Latin America. The widespread emergence of resistance to first-line drugs has further bolstered an urgent need for a new and cost-effective antimalarial(s). Thus, the present study enumerates the synthesis of novel hybrid dimethoxy pyrazole 1,3,5-triazine derivatives 7(a-j) and their in silico results short-listed three compounds with good binding energies and dock scores. Docking analysis shows that hydrogen-bonding predominates and typically involves key residues, such as Asp54, Tyr170, Ile164, and Arg122. The in vitro antimalarial evaluation of three top-ranked compounds (7e, 7g, and 7h) showed half-maximal inhibitory concentration values range from 53.85 to 100 μg/ml against chloroquine-sensitive strain 3D7 of Plasmodium falciparum. Compound 7e may be utilized as a lead for further optimization work in drug discovery due to good antimalarial activity.

A novel one-dimensional coordination polymer of cadmium(II)/triazine extending by di-chloro and di-iodo bridges

A new triazine ligand salt, 2,2′,2″-(1,3,5-triazine-2,4,6-triyl)tris(hydrazin-1-ium) chloride [THT·(HCl)3], and the one-dimensional coordination polymer of cadmium, [Cd2( µ-THT)( µ-Cl)( µ-I)I2]·2(H2O), are prepared and characterized by elemental analysis, Fourier-transform infrared spectroscopy, 1H NMR spectroscopy, and single-crystal X-ray diffraction (for the cadmium polymer). X-ray analysis revealed that the polymeric backbone is extended alternatively by di-iodo and di-chloro bridges; this type of bridge is not observed previously between any metal atoms. There are two types of cadmium atoms in the polymer: cadmium of the polymeric chain and terminal cadmiums. The geometry around the first (CdN2Cl2I2) is octahedral, while the latter (CdN3I2) has an incline to square-pyramidal geometry. The triazine ligand of this structure also bridges two cadmium atoms and acts as an N3 donor toward the terminal cadmium atoms and as an N2 donor toward the cadmium atoms of the chain. In the crystal network of the cadmium polymer, the hydrogen bonds of N–H···X (X: O, N, I) form different hydrogen bond motifs, including [Formula: see text](8), [Formula: see text](10), [Formula: see text](14), [Formula: see text](18), [Formula: see text](20), [Formula: see text](24), [Formula: see text](28), and [Formula: see text](32).

Structure-activity relationships (SAR) of triazine derivatives: Promising antimicrobial agents

The emergence of drug resistance has created unmet medical need for the development of new classes of antibiotics. Innovation of new antibacterial agents with new mode of action remains a high priority universally. Triazines are six-membered, nitrogen-containing heterocyclic scaffold with a wide range of pharmaceutical properties such as antibacterial, antifungal, anticancer, antioxidants, antitubercular, antimalarial, anti-HIV, anticonvulsant, anti-inflammatory, antiulcer, and analgesic activities. The present review focuses on the recent developments in the area of medicinal chemistry to discover various chemical structures as potential antimicrobial agents and their structure-activity relationships (SAR) studies are also discussed for further rational design of this kind of derivatives.

Recent development of leucyl-tRNA synthetase inhibitors as antimicrobial agents

Aminoacyl-tRNA synthetases (aaRSs) widely exist in organisms and mediate protein synthesis. Inhibiting these synthetases can lead to the termination of protein synthesis and subsequently achieve antibacterial and antiparasitic purposes. Moreover, the structures of aaRSs found in eukaryotes have considerable structural differences compared to those in prokaryotes, based on which it is possible to develop highly selective inhibitors. Leucyl-tRNA synthetase (LeuRS) with unique synthesis and editing sites is one of 20 kinds of aaRSs. Many inhibitors targeting LeuRS have been designed and synthesized, some of which have entered clinical use. For example, the benzoxaborole compound AN2690 has been approved by the FDA for the treatment of onychomycosis. AN3365 is suspended in the phase II clinical trial due to the rapid development of AN3365 resistance, but it may be used in combination with other antibiotics. The aaRSs, especially LeuRS, are being considered as targets of new potential anti-infective drugs for the treatment of not only bacterial or fungal infections but also infections by trypanosomes and malaria parasites. This review mainly describes the development of LeuRS inhibitors, focusing on their mechanisms of action, structure-activity relationships (SARs), and in vitro and in vivo activities.

Chloroacetamide derivatives as a promising topical treatment for fungal skin infections

The aim of this study was to evaluate the antifungal potential of 11 chloroacetamide derivatives and derivative incorporated into a film-forming system (FFS) as a potential alternative for the topical treatment of superficial and skin mycoses. The minimum inhibitory concentration (MIC) evaluation followed Clinical and Laboratory Standards Institute protocols M27-A3 (Candida) and M28-A2 (dermatophytes). Compounds 2, 3, and 4 were the most effective against Candida species (MIC range: 25-50 µg/mL) and dermatophytes (MIC range: 3.12-50 µg/mL). Compound 2 maintained its antifungal activity when incorporated in a FFS, with MIC values equivalent to the free compound. In addition, the compound does not act through complexation with ergosterol, suggesting that it may act on other targets of the fungal cell membrane. Chloroacetamide derivatives presented anti-Candida and anti-dermatophytic effectiveness. The FFS containing compound 2 has shown to be superior to traditional topical treatment of superficial and cutaneous fungal infections. It was found that these new chemical entities, with their applicability, are an excellent alternative to the topical treatment of fungal skin infections.

Cationic Amphipathic Triazines with Potent Anti-bacterial, Anti-inflammatory and Anti-atopic Dermatitis Properties

The emergence of multi-drug resistant bacteria forces the therapeutic world into a position, where the development of new and alternative kind of antibiotics is highly important. Herein, we report the development of triazine-based amphiphilic small molecular antibacterial agents as mimics of lysine- and arginine-based cationic peptide antibiotics (CPAs). These compounds were screened against a panel of both Gram-positive and Gram-negative bacterial strains. Further, anti-inflammatory evaluation of these compounds led to the identification of four efficient compounds, DG-5, DG-6, DL-5, and DL-6. These compounds displayed significant potency against drug-resistant bacteria, including methicillin-resistant S. aureus (MRSA), multidrug-resistant P. aeruginosa (MDRPA), and vancomycin-resistant E. faecium (VREF). Mechanistic studies, including cytoplasmic membrane depolarization, confocal imaging and flow cytometry suggest that DG-5, DG-6, and DL-5 kill bacteria by targeting bacterial membrane, while DL-6 follows intracellular targeting mechanism. We also demonstrate that these molecules have therapeutic potential by showing the efficiency of DG-5 in preventing the lung inflammation of lipopolysaccharide (LPS)-induced acute lung injury (ALI) mouse model. More interestingly, DL-6 exhibited impressive potency on atopic dermatitis (AD)-like skin lesions in BALB/c mice model by suppressing pro-inflammatory cytokines. Collectively, these results suggest that they can serve a new class of antimicrobial, anti-inflammatory and anti-atopic agents with promising therapeutic potential.

Exploring the Orthogonal Chemoselectivity of 2,4,6-Trichloro-1,3,5-Triazine (TCT) as a Trifunctional Linker With Different Nucleophiles: Rules of the Game

The study involves exploring the three orthogonal sites for aromatic nucleophilic substitution in cyanuric chloride (TCT). The preferential order of incorporation of different nucleophiles (such as alcohol, thiol, and amine) was addressed both experimentally and theoretically. The preferential order for incorporating nucleophiles in TCT was found to be alcohol > thiol > amine.

Anti‑breast cancer activity of selected 1,3,5‑triazines via modulation of EGFR‑TK

The present study investigated the effect of certain 1,3,5‑triazine derivatives on epidermal growth factor receptor‑tyrosine kinase (EGFR‑TK). The results suggested that 1,3,5‑triazine derivatives exhibited optimal drug likeness via molinspiration and proved to be effective drug candidates as potential anticancer agents. The molecules were demonstrated to interact with key catalytic residues of EGFR, including Asn818, Lys721, Leu694, Val702 and Met742 as demonstrated in molecular docking experiments. Compound 1d was demonstrated to be the most potent analogue with an inhibitory constant of 0.44 nM, against EGFR‑TK in in‑vitro enzyme inhibition assay. Compound 1d was further evaluated for its effect on the cellular viability of three breast cancer cell lines, including highly metastatic MDAMB231, human epidermal growth factor receptor 2‑positive BT474 and estrogen receptorpositive MCF7 cells, using an MTT assay and apoptosis analysis. Western blot analysis was performed to examine the levels of β‑catenin in the control and treated cells. Based on the findings of the current study, the chemical 1,3,5‑triazine series are potential novel inhibitors of EGFR‑TK and β‑catenin signaling, and may be potent anti‑breast cancer agents.

Synthesis and characterization of novel dimerics-triazine derivatives as potential anti-bacterial agents against MDR clinical isolates

Several dimerics-triazine Schiff bases displayed more potent anti-bacterial activity compared with ampicillin trihydrate. They revealed significantly low MIC values towards the tested MDR strains and showed a high selectivity index towards antimicrobial activity againstK. pneumoniaeandMRSA1compared to mammalian cells.

Novel 1,3,5-triazine derivatives exert potent anti-cervical cancer effects by modulating Bax, Bcl2 and Caspases expression

This study aimed to develop novel 1,3,5-triazine derivatives as potent anti-cervical cancer agents. The compounds were synthesized in short steps with an excellent yield and characterized via various spectroscopic and analytical methods. A structure-activity relationship study suggested that electron-withdrawing substituents showed greater anticancer activity than electron-donating groups. Compound 7p (p-fluoro) showed the highest activity against cervical cancer cells. In a nude mouse xenograft model inoculated with HeLa cells, 7p showed dose-dependent inhibition of cervical tumour growth. Histopathological examination of excised tumour-bearing tissues showed that 7p improved the microstructure in a dose-dependent manner. Compound 7p also increased the proportions of HeLa cells in G0/G1 and S-phase and significantly decreased that of G2/M-phase. The effects of 7p on C-caspase-3, C-caspase-9, Bcl-2 and Bax expression in HeLa cells were also determined.

Design and discovery of novel monastrol-1,3,5-triazines as potent anti-breast cancer agent via attenuating Epidermal Growth Factor Receptor tyrosine kinase

A novel series of hybrid analogues of monastrol-1,3,5-triazine were designed and developed via one-pot synthesis using Bi(NO₃)₃ as a catalyst. Entire compounds were evaluated for their anticancer activity against HeLa (cervical cancer), MCF-7 (breast cancer), HL-60 (Human promyelocytic leukemia), HepG2 (Hepatocellular carcinoma) and MCF 12A (normal epithelial breast cell line) using MTT assay, where they showed highest inhibitory activity against MCF-7. The molecules were also found to be non-toxic to MCF 12A cells. These molecules showed considerable inhibitory percentage against Epidermal Growth Factor Receptor tyrosine kinase (EGFR-TK), in in-vitro assay. Molecular docking study was carried out on the analogs and reference compound (Erlotinib) into the ATP binding site of EGFR-TK domain (PDB ID:1M17) to elucidate vital structural residues necessary for bioactivity. The effect of most active compound 7l was also estimated in-vivo in DMBA induced mammary tumor in female Sprague-Dawley rats. The effect of anti-breast cancer effect of 7l was quantified on the basis of tumour incidence, body weight and tumor volume in DMBA-induced rats. Its effect on biochemical parameters, such as antioxidant status (SOD, CAT, GPX and GSH) and lipid peroxidation was also studied. The compound 7l showed inhibition of EGFR downstream signalling in the western blot analysis.

Rational design, synthesis and biological screening of triazine-triazolopyrimidine hybrids as multitarget anti-Alzheimer agents

In our endeavor towards the development of potent multitarget ligands for the treatment of Alzheimer's disease, a series of triazine-triazolopyrimidine hybrids were designed, synthesized and characterized by various spectral techniques. Docking and scoring techniques were used to design the inhibitors and to display their interaction with key residues of active site. Organic synthesis relied upon convergent synthetic routes were mono and di-substituted triazines were connected with triazolopyrimidine using piperazine as a linker. In total, seventeen compounds were synthesized in which the di-substituted triazine-triazolopyrimidine derivatives 9a-d showed better acetylcholinesterase (AChE) inhibitory activity than the corresponding tri-substituted triazine-triazolopyrimidine derivatives 10a-f. Out of the disubstituted triazine-triazolopyrimidine based compounds, 9a and 9b showed encouraging inhibitory activity on AChE with IC₅₀ values 0.065 and 0.092 μM, respectively. Interestingly, 9a and 9b also demonstrated good inhibition selectivity towards AChE over BuChE by ∼28 folds. Furthermore, kinetic analysis and molecular modeling studies showed that 9a and 9b target both catalytic active site as well as peripheral anionic site of AChE. In addition, these derivatives effectively modulated Aβ self-aggregation as investigated through CD spectroscopy, ThT fluorescence assay and electron microscopy. Besides, these compounds exhibited potential antioxidants (2.15 and 2.91 trolox equivalent by ORAC assay) and metal chelating properties. In silico ADMET profiling highlighted that, these novel triazine derivatives have appropriate drug like properties and possess very low toxic effects in the primarily pharmacokinetic study. Overall, the multitarget profile exerted by these novel triazine molecules qualified them as potential anti-Alzheimer drug candidates in AD therapy.

Triazine as a promising scaffold for its versatile biological behavior

Among all heterocycles, the triazine scaffold occupies a prominent position, possessing a broad range of biological activities. Triazine is found in many potent biologically active molecules with promising biological potential like anti-inflammatory, anti-mycobacterial, anti-viral, anti-cancer etc. which makes it an attractive scaffold for the design and development of new drugs. The wide spectrum of biological activity of this moiety has attracted attention in the field of medicinal chemistry. Due to these biological activities, their structure-activity relationship has generated interest among medicinal chemists and this has culminated in the discovery of several lead molecules. The outstanding development of triazine derivatives in diverse diseases within very short span of time proves its magnitude for medicinal chemistry research. Therefore, these compounds have been synthesized as target structure by many researchers, and were further evaluated for their biological activities. In this review, we have compiled and discussed the biological potential of s-triazine derivatives, which could provide a low-height flying bird's eye view of the triazine derived compounds to a medicinal chemist, for a comprehensive and target oriented information for the development of clinically viable drugs.

Facile Synthesis, Characterization, and In Vitro Antimicrobial Screening of a New Series of 2,4,6-Trisubstituted-s-triazine Based Compounds

A series of new 2,4,6-trisubstituted-s-triazine was synthesized, assessed for antimicrobial activity, and characterized by FTIR, ¹HNMR, ¹³CNMR, and elemental analysis. The tested compounds, 4d, 4g, 4h, 4k, and 4n, have shown considerable in vitro antibacterial efficacy with reference to the standard drug ciprofloxacin (MIC 3.125 μgmL⁻¹ against B. subtilis, E. coli, and K. pneumoniae). It was observed that compounds 4d and 4h displayed equipotent antibacterial efficacy against B. subtilis (MIC 3.125 μgmL⁻¹) and S. aureus (MIC 6.25 μgmL⁻¹). The studies demonstrated that the para-fluorophenylpiperazine substituted s-triazine (4n) was potent and exhibited broad spectrum antibacterial activity against S. epidermidis, K. pneumoniae, and P. aeruginosa with MIC of 6.25 μgmL⁻¹ and for E. coli, it showed an MIC of 3.125 μgmL⁻¹ equipotent with reference to the standard drug. Among all the compounds under investigation, compound 4g also demonstrated significant antifungal activity (3.125 μgmL⁻¹) against C. albicans.

Discovery of novel 1,3,5-triazine-thiazolidine-2,4-diones as dipeptidyl peptidase-4 inhibitors with antibacterial activity targeting the S1 pocket for the treatment of type 2 diabetes

A novel series of 1,3,5-triazine-thiazolidine-2,4-diones was synthesized and characterized by a number of analytical and spectroscopic techniques.