Synthesis, antitumor evaluation and 3D-QSAR studies of [1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine derivatives

Synthesis, biological evaluation and molecular docking of N, N’-bis([1,2,4]triazole[4,3-b][1,2,4,5]tetrazine-6-yl)alkylamine derivatives as potent c-Met antagonists

A series of N, N’-bis([1,2,4]triazole[4,3- b][1,2,4,5]tetrazine-6-yl)alkylamine derivatives is designed, synthesized and evaluated for their inhibition activities against three tumor cell lines and c-Met kinase activity in vitro. These compounds are fully characterized by 1H NMR, 13C NMR, MS, IR and elemental analysis. Antitumor experiments indicate that some of these compounds exhibit significant inhibition activities against A549, Bewo and MCF-7 cancer cell lines. Among them, the IC50 values of 4a indicate better antitumor activities against the A549 (1.21 μM), Bewo (0.68 μM) and MCF-7 (3.74 μM) cell lines than the positive agent cisplatin (9.97 μM for A549, 10.46 μM for Bewo, and 15.03 μM for MCF-7), respectively.

Comparison of various methods for validity evaluation of QSAR models

BACKGROUND

Quantitative structure-activity relationship (QSAR) modeling is one of the most important computational tools employed in drug discovery and development. The external validation of QSAR models is the main point to check the reliability of developed models for the prediction activity of not yet synthesized compounds. It was performed by different criteria in the literature.

METHODS

In this study, 44 reported QSAR models for biologically active compounds reported in scientific papers were collected. Various statistical parameters of external validation of a QSAR model were calculated, and the results were discussed.

RESULTS

The findings revealed that employing the coefficient of determination (r²) alone could not indicate the validity of a QSAR model. The established criteria for external validation have some advantages and disadvantages which should be considered in QSAR studies.

CONCLUSION

This study showed that these methods alone are not only enough to indicate the validity/invalidity of a QSAR model.

Synthesis of novel [1,2,4]triazolo[1,5-b][1,2,4,5]tetrazines and investigation of their fungistatic activity

A series of novel [1,2,4]triazolo[1,5-b][1,2,4,5]tetrazines has been synthesized through oxidation reaction of the corresponding 3,6-disubstituted 1,2,4,5-tetrazines bearing amidine fragments. It is shown that the heterocyclic systems obtained can be modified easily at C(3) position in the reactions with aliphatic alcohols and amines. Also, the reactivity of [1,2,4]triazolo[1,5-b][1,2,4,5]tetrazines towards CH-active compounds has been studied. The obtained triazolo[1,5-b]annulated 1,2,4,5-tetrazines proved to be active in micromolar concentrations in vitro against filamentous anthropophilic and zooanthropophilic dermatophyte fungi (Trichophyton, Microsporum and Epidermofiton), which cause skin and its appendages (hair, nails) diseases.

An insight on medicinal attributes of 1,2,4-triazoles

The present review aims to summarize the pharmacological profile of 1,2,4-triazole, one of the emerging privileged scaffold, as antifungal, antibacterial, anticancer, anticonvulsant, antituberculosis, antiviral, antiparasitic, analgesic and anti-inflammatory agents, etc. along with structure-activity relationship. The comprehensive compilation of work carried out in the last decade on 1,2,4-triazole nucleus will provide inevitable scope for researchers for the advancement of novel potential drug candidates having better efficacy and selectivity.

Synthesis, biological evaluation, and molecular docking of ((4-([1,2,4]triazolo[4,3-b][1,2,4,5]tetrazin-6-yl) piperazin-1-yl)methyl) benzohydrazide derivatives

A series of ((4-([1,2,4]triazolo[4,3- b][1,2,4,5] methyl) benzo-hydrazide derivatives was designed, synthesized, and evaluated for their inhibition activities against five tumor cells and c-Met kinase in vitro. These compounds were fully characterized by 1H NMR, 13C NMR, MS, and elemental analysis. Antitumor experiments indicated that some compounds exhibited significant inhibition activities against A549 and Bewo. Especially, the IC50 values of 5f (12 μM), 5h (7.1 μM), 6a (8.4 μM), and 6d (9.2 μM) demonstrated better antitumor activities against A549 than the positive agent cisplatin (13.3 μM), and the IC50 value of 6a (5.2 μM) exhibited better antitumor activity against Bewo than cisplatin (7.7 μM).

Synthesis and biological evaluation of novel 6-alkoxy-3-aryl-[1,2,4]triazolo[4,3-b][1,2,4,5] tetrazines

A series of 6-alkoxy-3-aryl-[1,2,4]triazolo[4,3- b][1,2,4,5] tetrazine derivatives is synthesized and evaluated for their antitumor activities. These compounds exhibit potent antiproliferative activities against A549, Bewo, and MCF-7 cells. Molecular docking is performed to study the inhibitor–c-Met kinase interactions, and the results show that 6-ethoxyl-3-phenylethyl-[1,2,4]triazolo[4,3- b][1,2,4,5] tetrazine is potently bound to c-Met kinase with two hydrogen bonds and one π–π interaction. Based on these preliminary results, it is thought that compound 6-ethoxyl-3-phenylethyl-[1,2,4]triazolo[4,3- b][1,2,4,5] tetrazine with potent inhibitory activity may be a potential anticancer agent.

Preparation of Unsymmetrical 1,2,4,5-Tetrazines via a Mild Suzuki Cross-Coupling Reaction

N-Alkyl substituted chlorotetrazines were coupled with various boronic acids under Suzuki conditions in high yield at room temperature, giving a mild and straightforward synthetic route toward diverse unsymmetrical 1,2,4,5-tetrazines, a rare heteroarene. This chemistry not only expands the known substrate scope of tetrazine cross-coupling reactions but also allows for the synthesis of novel, tetrazine-containing biologically active molecules with improved DMPK properties.