Synthesis, biological evaluation, and docking study of a series of 1,4‐disubstituted 1,2,3‐triazole derivatives with an indole‐triazole‐peptide conjugate

Indole clubbed 2,4-thiazolidinedione linked 1,2,3-triazole as a potent antimalarial and antibacterial agent against drug-resistant strain and molecular modeling studies

In the face of escalating challenges of microbial resistance strains, this study describes the design and synthesis of 5-({1-[(1H-1,2,3-triazol-4-yl)methyl]-1H-indol-3-yl}methylene)thiazolidine-2,4-dione derivatives, which have demonstrated significant antimicrobial properties. Compared with the minimum inhibitory concentrations (MIC) values of ciprofloxacin on the respective strains, compounds 5a, 5d, 5g, 5l, and 5m exhibited potent antibacterial activity with MIC values ranging from 16 to 25 µM. Almost all the synthesized compounds showed lower MIC compared to standards against vancomycin-resistant enterococcus and methicillin-resistant Staphylococcus aureus strains. Additionally, the majority of the synthesized compounds demonstrated remarkable antifungal activity, against Candida albicans and Aspergillus niger, as compared to nystatin, griseofulvin, and fluconazole. Furthermore, the majority of compounds exhibited notable inhibitory effects against the Plasmodium falciparum strain, having IC50 values ranging from 1.31 to 2.79 μM as compared to standard quinine (2.71 μM). Cytotoxicity evaluation of compounds 5a-q on SHSY-5Y cells at up to 100 μg/mL showed no adverse effects. Comparison with control groups highlights their noncytotoxic characteristics. Molecular docking confirmed compound binding to target active sites, with stable protein-ligand complexes displaying drug-like molecules. Molecular dynamics simulations revealed dynamic stability and interactions. Rigorous tests and molecular modeling unveil the effectiveness of the compounds against drug-resistant microbes, providing hope for new antimicrobial compounds with potential safety.

Synthesis, Molecular Docking, and Biological Evaluation of Novel Indole-triazole Conjugates

BACKGROUND

Indole-triazole conjugates have emerged as promising candidates for new drug development. Their distinctive structural characteristics, coupled with a wide array of biological activities, render them a captivating and promising field of research for the creation of novel pharmaceutical agents.

OBJECTIVE

This study aimed to synthesize indole-triazole conjugates to investigate the influence of various substituents on the functional characteristics of indole-triazole hybrids. It also aimed to study the binding modes of new hybrids with the DNA Gyrase using molecular docking studies.

METHODS

A new set of indole-triazole hybrids was synthesized and characterized using various physicochemical and spectral analyses. All hybrids underwent in-silico pharmacokinetic prediction studies. The antimicrobial efficacy of the hybrids was assessed using tube dilution and agar diffusion methods. Additionally, the in-vitro antioxidant activity of synthesized compounds was determined using the 1,1-diphenyl-2-picryl-hydrazyl free radical scavenging assay. Furthermore, in silico molecular docking studies were performed to enhance our comprehension of how the synthesized compounds interact at the molecular level with DNA gyrase.

RESULTS

Pharmacokinetic predictions of synthesized hybrids indicated favourable pharmacokinetic profiles, and none of the compounds violated the Lipinski rule of five. Notably, compound 6, featuring a cyclohexanol substituent, demonstrated superior antimicrobial and antioxidant activity (EC50 value = 14.23 μmol). Molecular docking studies further supported the in vitro antioxidant and antimicrobial findings, revealing that all compounds adeptly fit into the binding pocket of DNA Gyrase and engaged in interactions with crucial amino acid residues.

CONCLUSION

In summary, our research underscores the efficacy of molecular hybridization in shaping the physicochemical, pharmacokinetic, and biological characteristics of novel indole-triazole derivatives.

A Review on Indole-triazole Molecular Hybrids as a Leading Edge in Drug Discovery: Current Landscape and Future Perspectives

Molecular hybridization is a rational design strategy used to create new ligands or prototypes by identifying and combining specific pharmacophoric subunits from the molecular structures of two or more known bioactive derivatives. Molecular hybridization is a valuable technique in drug discovery, enabling the modulation of unwanted side effects and the creation of potential dual-acting drugs that combine the effects of multiple therapeutic agents. Indole-triazole conjugates have emerged as promising candidates for new drug development. The indole and triazole moieties can be linked through various synthetic strategies, such as click chemistry or other coupling reactions, to generate a library of diverse compounds for biological screening. The achievable structural diversity with indole-triazole conjugates offers avenues to optimize their pharmacokinetic and pharmacodynamic attributes, amplifying their therapeutic efficacy. Researchers have extensively tailored both indole and triazole frameworks with diverse modifications to comprehend their impact on the drug's pharmacokinetic and pharmacodynamic characteristics. The current review article endeavours to explore and discuss various research strategies to design indoletriazole hybrids and elucidate their significance in a variety of pathological conditions. The insights provided herein are anticipated to be beneficial for the researchers and will likely encourage further exploration in this field.

Green Approach Toward Triazole Forming Reactions for Developing Anticancer Drugs

Compounds containing triazole have many significant applications in the dye and ink industry, corrosion inhibitors, polymers, and pharmaceutical industries. These compounds possess many antimicrobial, antioxidant, anticancer, antiviral, anti-HIV, antitubercular, and anticancer activities. Several synthetic methods have been reported for reducing time, minimizing synthetic steps, and utilizing less hazardous and toxic solvents and reagents to improve the yield of triazoles and their analogues synthesis. Among the improvement in methods, green approaches towards triazole forming biologically active compounds, especially anticancer compounds, would be very important for pharmaceutical industries as well as global research community. In this article, we have reviewed the last five years of green chemistry approaches on click reaction between alkyl azide and alkynes to install 1,2,3-triazole moiety in natural products and synthetic drug-like molecules, such as in colchicine, flavanone cardanol, bisphosphonates, thiabendazoles, piperazine, prostanoid, flavonoid, quinoxalines, C-azanucleoside, dibenzylamine, and aryl-azotriazole. The cytotoxicity of triazole hybrid analogues was evaluated against a panel of cancer cell lines, including multidrug-resistant cell lines.

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

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

Mechanosynthesis of Triazolyl-bis(indolyl)methane Pharmacophores via Gold Catalysis: A Prelude to Their Molecular Electronic Properties and Biological Potency

Chemical structures possessing both 1,2,3-triazole and bis(indolyl)methane fragments gained considerable interest in drug synthesis owing to their established biological efficacies. However, 1,2,3-triazoles linked at the bridging position of bis(indolyl)methane is a logical and unexplored design approach. In this regard, nine new triazolyl-bis(indolyl)methane conjugates under AuCl catalyzed ball-milling conditions were accomplished. Comparative evaluation on absorptive and emissive properties of the synthesized dyads were also analyzed. To unravel the influence of different peripheral substituents on the electronic structure and π-orbital properties, theoretical investigations were performed. Screening of molecules for free radical scavenging, anti-inflammatory and antidiabetic showed comparable potency against reference drugs. In particular, compounds 7 h, 7 d and 7 a displayed good efficiency of α-amylase inhibition. The DNA gyrase inhibitory potential of all compounds were assessed in silico which revealed high binding affinity (ΔG=-8.99 Kcal/mol) for 7 i followed by 7 h (ΔG=-7.80 Kcal/mol) with the targeted protein.

Synthesis and bioactivities of new N-terminal dipeptide mimetics with aromatic amide moiety: Broad-spectrum antibacterial activity and high antineoplastic activity

The increasingly growing epidemics of multidrug-resistant bacteria are becoming severe public health threat. There is in an urgent need to develop new antibacterial agents with broad-spectrum antibacterial activity and high selectivity. Here, a series of N-terminal dipeptide mimetics with an aromatic amide moiety were synthesized from amino acids. The effects of amino acid type and aromatic moiety on the biological activities of the mimetics were evaluated. The dipeptide mimetics not only showed significant broad-spectrum antibacterial activity against Gram-negative (Escherichia coli and Klebsiella pneumoniae), Gram-positive (Staphylococcus aureus) and drug-resistant bacterium MRSA (methicillin-resistant S. aureus) but also demonstrated high selectivity for S. aureus versus mammalian erythrocytes. The coupling product of L-valine with p-alkynylaniline (dipeptide mimetic 7) exhibited the best antibacterial activities with minimum inhibitory concentration (MIC) ranging from 2.5 to 5 μg/mL. Moreover, the bactericidal kinetics and multi-passage resistance tests indicated that the mimetic 7 both rapidly killed bacteria and had a low probability of emergence of antimalarial resistance. Meanwhile, the mimetic 7 possessed the ability to both inhibit bacterial biofilm formation and eradicate mature biofilm. The depolarization and destruction of the bacterial cell membrane is the main sterilization mechanism, which hinders the propensity to develop bacterial resistance. Furthermore, the mimetic 7 also showed good antineoplastic activity against gastric cancer cell (SGC 7901, IC₅₀ = 70.8 μg/mL), while it had very low toxicity to mammalian cell (L929). The mimetics bear considerable potential to be used as antibacterial and anticancer agents to combat antibiotic resistance.

1,2,3-Triazole hybrids as anticancer agents: A review

Despite the advancements in the development of anticancer agents, more effective and safer anticancer drugs still need to be developed as the current agents cause unwanted side effects and many patients have become drug resistant. 1,2,3-Triazoles, due to their remarkable biological potential, have received considerable attention in drug discovery for the development of anticancer agents. The present review article presents an overview of the recent advances in 1,2,3-triazole hybrids with anticancer potential over the last 2 years, their chemical structures, structure-activity relationships, and mechanisms of action, as well as insights into the docking studies.

1,2,3-Triazole-Containing Compounds as Anti-Lung Cancer Agents: Current Developments, Mechanisms of Action, and Structure-Activity Relationship

Lung cancer is the most common malignancy and leads to around one-quarter of all cancer deaths. Great advances have been achieved in the treatment of lung cancer with novel anticancer agents and improved technology. However, morbidity and mortality rates remain extremely high, calling for an urgent need to develop novel anti-lung cancer agents. 1,2,3-Triazole could be readily interact with diverse enzymes and receptors in organisms through weak interaction. 1,2,3-Triazole can not only be acted as a linker to tether different pharmacophores but also serve as a pharmacophore. This review aims to summarize the recent advances in 1,2,3-triazole-containing compounds with anti-lung cancer potential, and their structure-activity relationship (SAR) together with mechanisms of action is also discussed to pave the way for the further rational development of novel anti-lung cancer candidates.

Simultaneous ultrasound- and microwave-assisted one-pot 'click' synthesis of 3-formyl-indole clubbed 1,2,3-triazole derivatives and their biological evaluation

An environment friendly, high yielding, promising one-pot protocol for the click reaction of N-propargyl-3-formylindole 2(a-b), chloroacetic acid/ester 3(a-b) and sodium azide, leading to the formation of 3-formyl-indole clubbed 1,4-disubstituted-1,2,3-triazole derivatives 4(a-b), 5(a-b) and 6(a-f) aided by CuI catalyst accomplished under acceleration of simultaneous ultrasound and microwave irradiation in a very short reaction time has been described. Further, acid derivative 4(a-b) is subjected to acid-amine coupling reaction with secondary amine (p-t) in the presence of HATU to afford 6(p-t) and 7(p-t). The perspective of this protocol is to get rid of the hectic preparation and handling of organic azide which are generated in situ. Consequently, this protocol blossoms the click process by making it environment benign, user-friendly, safe and clean technique. All the synthesized compounds have been preliminarily screen for their in vitro antimicrobial activity against a panel of pathogenic strains. The majority of compounds possess noticeably inhibitory action against E. Coli, S. Typhi, P. Aeruginosa, C. tetani, S. aureus and B. subtillis. Among all compounds, 6p and 7q exhibit excellent inhibitory action against E.Coli and P. Aeruginosa strain, respectively, as compared to standard drug. One compound 5b shows remarkable potency against fungal strain. Molecular docking study was carried out to understand binding of compound with protein. In silico ADME prediction was carried out to check physicochemical properties of synthesized compound.

Insights into the antibacterial activity of cottonseed protein-derived peptide against Escherichia coli

In the study, antibacterial peptides were separated and identified from cottonseed protein hydrolysates and the interactions between antibacterial peptides and Escherichia coli were further investigated. Firstly, by using a combined strategy of Amberlite CG-50 ion exchange chromatography and reversed-phase high-performance liquid chromatography, three peptides with antibacterial activity were purified and identified, including HHRRFSLY, KFMPT, and RRLFSDY. Interestingly, HHRRFSLY and RRLFSDY exhibited higher inhibition activity with the IC50 value of 0.26 mg mL-1 and 0.58 mg mL-1 (p < 0.05), respectively. Flow cytometry results showed that the incubation of antibacterial peptides with E. coli could cause damage to the integrity of the E. coli cell membrane. Transmission electron microscopy and scanning electron microscopy results revealed the damage caused to the bacterial cell surface and the leakage of cytoplasmic content by the antibacterial peptides. Molecular docking studies indicated that HHRRFSLY, KFMPT, and RRLFSDY have a good binding affinity to the active sites of the surface protein (OmpF) mainly through a hydrogen bond and salt bridge. The results here showed that the antibacterial peptides derived from cottonseed protein could be used as a good choice for functional foods or related drugs, and also shed light on further studies of antibacterial mechanism.