2,4(5)-Diarylimidazoles: Synthesis and biological evaluation of a new class of sodium channel blockers against hNav1.2

Molecular Characterization of Membrane Steroid Receptors in Hormone-Sensitive Cancers

Cancer is one of the most common causes of death worldwide, and its development is a result of the complex interaction of genetic factors, environmental cues, and aging. Hormone-sensitive cancers depend on the action of one or more hormones for their development and progression. Sex steroids and corticosteroids can regulate different physiological functions, including metabolism, growth, and proliferation, through their interaction with specific nuclear receptors, that can transcriptionally regulate target genes via their genomic actions. Therefore, interference with hormones’ activities, e.g., deregulation of their production and downstream pathways or the exposition to exogenous hormone-active substances such as endocrine-disrupting chemicals (EDCs), can affect the regulation of their correlated pathways and trigger the neoplastic transformation. Although nuclear receptors account for most hormone-related biologic effects and their slow genomic responses are well-studied, less-known membrane receptors are emerging for their ability to mediate steroid hormones effects through the activation of rapid non-genomic responses also involved in the development of hormone-sensitive cancers. This review aims to collect pre-clinical and clinical data on these extranuclear receptors not only to draw attention to their emerging role in cancer development and progression but also to highlight their dual role as tumor microenvironment players and potential candidate drug targets.

Synthesis and Study of Prototropic Tautomerism of 2-(2-Furyl)-1-hydroxyimidazoles

Novel 2-(2-furyl)imidazole derivatives were synthesised. 2-(2-Furyl)-1-methoxyimidazoles and 2-(2-furyl)-1-methylimidazole 3-oxides were used as model compounds in the study of the prototropic tautomerism of 2-(2-furyl)-1-hydroxyimidazoles by means of 1H, 13C NMR and UV/vis spectroscopies. It was demonstrated that the interaction of the π-excessive furyl moiety with an electron-withdrawing carbonyl group in position 5 of imidazole stabilised the N-hydroxy tautomeric form in both deuterated chloroform and d6-DMSO. In ethanol the N-oxide tautomer is also present along with the prevailing N-hydroxyimidazole.

Modular Synthesis of Di- and Trisubstituted Imidazoles from Ketones and Aldehydes: A Route to Kinase Inhibitors

A one-pot and modular approach to the synthesis of 2,4(5)-disubstituted imidazoles was developed based on ketone oxidation, employing catalytic HBr and DMSO, followed by imidazole condensation with aldehydes. This methodology afforded twenty-nine disubstituted NH-imidazoles (23%–85% yield). A three-step synthesis of 20 kinase inhibitors was achieved by employing this oxidation–condensation protocol, followed by bromination and Suzuki coupling in the imidazole ring to yield trisubstituted NH-imidazoles (23%–69%, three steps). This approach was also employed in the synthesis of known inhibitor GSK3037619A.

Discovery of antitubercular 2,4-diphenyl-1H-imidazoles from chemical library repositioning and rational design

TB, caused by Mycobacterium tuberculosis, is one of the deadliest infections worldwide. The co-infection with HIV and the emergence of multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) strains have further increased the burden for this disease. In the attempt to respond to the constant need of novel therapeutic options, we herein report the discovery of 2,4-diphenyl-1H-imidazoles as effective antitubercular agents, with MIC in the low micromolar range against actively replicating and persistent M. tuberculosis strains. The good activity, along with the lack of toxicity and the feasible synthesis, underscore their value as novel scaffolds for the development of new anti-TB drugs.

Imidazoles from nitroallylic acetates and α-bromonitroalkenes with amidines: synthesis and trypanocidal activity studies

One-pot cascade reactions of amidines with nitroallylic acetates and α-bromonitroalkenes provide functionalized imidazoles that exhibit trypanocidal activity.

Synthesis of imidazoles via cascade reaction of nitroallylic acetates with amidines and studies on their trypanocidal activity

Functionalized imidazoles derived from nitroallylic acetates and amidines exhibit potent activity against T. cruzi, the etiological agent of Chagas disease.

Inhibition of NaV1.6 sodium channel currents by a novel series of 1,4-disubstituted-triazole derivatives obtained via copper-catalyzed click chemistry

We have synthesized and evaluated a series of 1,4-disubstituted-triazole derivatives for inhibition of the rat Na(V)1.6 sodium channel isoform, an isoform thought to play an important role in controlling neuronal firing. Starting from a series of 2,4(1H)-diarylimidazoles previously published, we decided to extend the SAR study by replacing the imidazole with a different heterocyclic scaffold and by varying the aryl substituents on the central aromatic ring. The 1,4-disubstituted 1,2,3-triazoles were prepared employing the copper-catalyzed azide-alkyne cycloaddition (CuAAC). Many of the new molecules were able to block the rNa(v)1.6 currents at 10 μM by over 20%, displaying IC(50) values ranging in the low micromolar, thus indicating that triazole can efficiently replace the central heterocyclic core. Moreover, the introduction of a long chain at C4 of the central triazole seems beneficial for increased rNa(v)1.6 current block, whereas the length of N1 substituent seems less crucial for inhibition, as long as a phenyl ring is not direcly connected to the triazole. These results provide additional information on the structural features necessary for block of the voltage-gated sodium channels. These new data will be exploited in the preparation of new compounds and could result in potentially useful AEDs.

Anticonvulsant activity of 2,4(1H)-diarylimidazoles in mice and rats acute seizure models

2,4(1H)-Diarylimidazoles have been previously shown to inhibit hNa(V)1.2 sodium (Na) channel currents. Since many of the clinically used anticonvulsants are known to inhibit Na channels as an important mechanism of their action, these compounds were tested in two acute rodent seizure models for anticonvulsant activity (MES and scMet) and for sedative and ataxic side effects. Compounds exhibiting antiepileptic activity were further tested to establish a dose response curve (ED(50)). The experimental data identified four compounds with anticonvulsant activity in the MES acute seizure rodent model (compound 10, ED(50)=61.7mg/kg; compound 13, ED(50)=46.8mg/kg, compound 17, ED(50)=129.5mg/kg and compound 20, ED(50)=136.7mg/kg). Protective indexes (PI=TD(50)/ED(50)) ranged from 2.1 (compound 10) to greater than 3.6 (compounds 13, 17 and 20). All four compounds were shown to inhibit hNa(V)1.2 in a dose dependant manner. Even if a correlation between sodium channel inhibition and anticonvulsant activity was unclear, these studies identify four Na channel antagonists with anticonvulsant activity, providing evidence that these derivatives could be potential drug candidates for development as safe, new and effective antiepileptic drugs (AEDs).

NMR analysis of a series of imidazobenzoxazines

The complete (1)H and (13)C NMR assignment of a series of imidazobenzoxazines by a combination of one- and two-dimensional experiments (COSY, HSQC and HMBC) is studied. Moreover, 2D NOESY and 1D selective NOESY are reported. This procedure allows the identification of the regioisomers obtained.