Synthesis and pharmacological activity of 2-(biphenyl-4-yl)imidazo[1,2-a]benzimidazoles

The medicinal panorama of benzimidazoles and their scaffolds as anticancer and antithrombotic agents: A review

Nitrogen-containing heterocyclic scaffolds have become a prospective pharmacophore with therapeutic importance due to their biological similarities with natural and synthetic drugs. Among all nitrogen heterocyclic compounds, benzimidazoles and their derivatives are privileged molecules structurally akin to naturally available nucleotides, enabling them to intercommunicate with numerous biopolymers in biological systems. This reason enlightens modern researchers worldwide to assess their potential significance in the context of synthetic and biological chemistry. Therefore, it is crucial to merge the latest data with the prior documentation to apprehend the ongoing situation of the benzimidazole moiety in various therapeutic zones of research. The current work displays that the benzimidazole center is a versatile nucleus that offers the necessary data of synthetic alterations for pre-existing compounds to provide new scaffolds to resist numerous therapeutic sectors, including those associated with anticancer and antithrombosis. Due to the potential significance of benzimidazoles, this review aims to emphasize the latest innovations in synthesizing several other notable benzimidazole substrates and their significant pharmacological prospects for the future, including anticancer and antithrombosis.

Discovery and evaluation of biphenyl derivatives of 2-iminobenzimidazoles as prototype dual PTP1B inhibitors and AMPK activators with in vivo antidiabetic activity

This work describes the synthesis of series hydrobromides of N-(4-biphenyl)methyl-N'-dialkylaminoethyl-2-iminobenzimidazoles, which, due to the presence of two privileged structural fragments (benzimidazole and biphenyl moieties), can be considered as bi-privileged structures. Compound 7a proved to activate AMP-activated kinase (AMPK) and simultaneously inhibit protein tyrosine phosphatase 1B (PTP1B) with similar potency. This renders it an interesting prototype of potential antidiabetic agents with a dual-target mechanism of action. Using prove of concept in vivo study, we show that dual-targeting compound 7a has a disease-modifying effect in a rat model of type 2 diabetes mellitus via improving insulin sensitivity and lipid metabolism.

DF-5 COMPOUND DELAYS DEVELOPMENT OF DIABETIC NEPHROPATHY IN RATS

Advanced glycation end-products play an important role in the development of diabetic complications, so slowing down of glycated proteins’ cross-links formation have been suggested as a potential therapeutic option for the treatment of vascular diabetic complications and preventing their progression.

The aim of the work was to assess the influence of novel anticrosslinking agent DF-5 on the renal advanced glycation end-products and collagen contents, body weight, blood glucose and glycated hemoglobin levels and the development of early renal disease in streptozotocin-induced diabetic rats.

Materials and methods. 40 male Sprague-Dawley rats were used in the study. Two months after inducing diabetes, the study substance was administered intragastrically once a day for 28 days (12.5 mg/kg). Measurements included the assessment of blood glucose and HbA1c levels, the evaluation of the renal function, and the results of histology and immunohistochemical staining of kidneys.

Results. A repeated intragastric administration of DF-5 for 30 days significantly reduced the level of HbA1c in the blood, but did not affect the level of fasting blood glucose. DF-5 compound significantly reduced proteinuria and prevented kidney damage in experimental animals by limiting damage of the glomeruli and tubules. It was found that DF-5 inhibits the progression of an early renal dysfunction in rats with streptozotocin-induced diabetic nephropathy. This was associated with a decreased accumulation of advanced glycation end-products in the kidney, accompanied by the improvement of both renal morphology and function.

Conclusion. The results obtained provide investigators with additional therapeutic options for the treatment of diabetic nephropathy and possibly other complications of diabetes.

Search for compounds with antioxidant and antiradical activity among N9-substituted 2-(biphenyl-4-yl)imidazo[1,2-a]benzimidazoles

Introduction: Biphenyl and imidazobenzimidazole derivatives attract ongoing attention as a combination of these two privileged substructures with promising pharmacological activities. The aim of this study was to synthesize and investigate in vitro antioxidant activity of promising novel compounds: 2-(biphenyl-4-yl)imidazo[1,2-a]benzimidazoles.

Materials and methods: The newly synthesized compounds were characterized by IR, 1H NMR and CHBr(Cl)NO analyses. All newly synthesized compounds were screened for their in vitro antioxidant activity: inhibition of lipid peroxidation (LPO), 2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) radical cation decolorization and inhibition of hemoglobin (Hb)-H2O2-induced luminol chemiluminescence.

Results and discussion: 2-Amino-3-[(2-biphenyl-4-yl)-2-oxo-ethyl)]-1-R-1Н-benzimidazolium bromides were synthesized, and their cyclization into functionalized imidazo[1,2-a]benzimidazole derivatives was studied. The resulting compounds showed LPO inhibitory activity comparable to that of dibunol. Compounds 1a and 1d (see graphical abstract), containing a methyl or dimethylaminoethyl substituent in the N9 position also proved to be equally highly active in the Hb-H2O2-induced luminol chemiluminescence model, while compound 1a was somewhat more active than 1d in the ABTS• radical scavenging assay.

Conclusion: The study showed that compounds 1a and 1d have the highest antioxidant activity. Thus, this new class of 2-(biphenyl-4-yl)imidazo[1,2-a]benzimidazole derivatives represents a valuable leading series with great potential for use as antioxidants and as promising candidates for further efficacy evaluation.

Graphical abstract: