Synthesis, crystal structure determination and antiproliferative activity of novel 2-amino-4-aryl-4,10-dihydro[1,3,5]triazino[1,2-a]benzimidazoles

Therapeutic Potential of Benzimidazoisoquinoline Derivatives in Alleviating Murine Hepatic Fibrosis

Short Title: Benzimidazoisoquinoline derivatives as potent antifibrotics Hepatic fibrosis is a pathological condition of liver disease with an increasing number of cases worldwide. Therapeutic strategies are warranted to target the activated hepatic stellate cells (HSCs), the collagen-producing cells, an effective strategy for controlling the disease progression. Benzimidazoisoquinoline derivatives were synthesized as hybrid molecules by the combination of benzimidazoles and isoquinolines to evaluate their anti-fibrotic potential using an in-vitro and in-vivo model of hepatic fibrosis. A small library of benzimidazoisoquinoline derivatives (1-17 and 18-21) was synthesized from 2-aryl benzimidazole and acetylene functionalities through C-H and N-H activation. Compounds (10 and its recently synthesized derivatives 18-21) depicted a significant decrease in PDGF-BB and/or TGFβ-induced proliferation (1.7-1.9 -fold), migration (3.5-5.0 -fold), and fibrosis-related gene expressions in HSCs. These compounds could revert the hepatic damage caused by chronic exposure to hepatotoxicants, ethanol, and/or carbon tetrachloride as evident from the histological, biochemical, and molecular analysis. Anti-fibrotic effect of the compounds was supported by the decrease in the malondialdehyde level, collagen deposition, and gene expression levels of fibrosis-related markers such as α-SMA, COL1α1, PDGFRβ, and TGFRIIβ in the preclinical models of hepatic fibrosis. In conclusion, the synthesized benzimidazoisoquinoline derivatives (compounds 18, 19, 20, and 21) possess anti-fibrotic therapeutic potential against liver fibrosis.

Fused Triazinobenzimidazoles Bearing Heterocyclic Moiety: Synthesis, Structure Investigations, and In Silico and In Vitro Biological Activity

[1,3,5]Triazino[1,2-a]benzimidazole-2-amines bearing heterocyclic moiety in 4-position were synthesized. The compounds were characterized by elemental analysis, IR, ¹H-NMR, ¹³C-NMR, and HRMS spectroscopy. The molecular geometry and electron structure of these molecules were theoretically studied using density functional theory (DFT) methods. The molecular structure of the synthesized fused triazinobenzimidazole was confirmed to correspond to the 3,4-dihydrotriazinobenzimidazole structure through the analysis of spectroscopic NMR data and DFT calculations. The antinematodic activity was evaluated in vitro on isolated encapsulated muscle larvae (ML) of Trichinella spiralis. The results showed that the tested triazinobenzimidazoles exhibit significantly higher efficiency than the conventional drug used to treat trichinosis, albendazole, at a concentration of 50 μg/mL. The compound 3c substituted with a thiophen-2-yl moiety exhibited the highest anthelmintic activity, with a larvicidal effect of 58.41% at a concentration of 50 μg/mL after 24 h of incubation. Following closely behind, the pyrrole analog 3f demonstrated 49.90% effectiveness at the same concentration. The preliminary structure-anti-T. spiralis activity relationship (SAR) of the analogues in the series was discussed. The cytotoxicity of the benzimidazole derivatives against two normal fibroblast cells (3T3 and CCL-1) and two cancer human cell lines (MCF-7 breast cancer cells and chronic myeloid leukemia cells AR-230) was evaluated using the MTT-dye reduction assay. The screening results indicated that the compounds showed no cytotoxicity against the tested cell lines. An in silico study of the physicochemical and pharmacokinetic characteristics of the novel synthesized fused triazinobenzimidazoles showed that they were characterized by a significant degree of drug-likeness and optimal properties for anthelmintic agents.

Benzimidazole Derivatives as New Potential NLRP3 Inflammasome Inhibitors That Provide Neuroprotection in a Rodent Model of Neurodegeneration and Memory Impairment

Objective

The study investigated the effect of newly synthesized benzimidazole derivatives against ethanol-induced neurodegeneration. According to evidence, ethanol consumption may cause a severe insult to the central nervous system (CNS), resulting in mental retardation, neuronal degeneration, and oxidative stress. Targeting neuroinflammation and oxidative stress may be a useful strategy for preventing ethanol-induced neurodegeneration.

Methodology

Firstly, the newly synthesized compounds were subjected to molecular simulation and docking in order to predict ligand binding status. Later, for in vivo observations, adult male Sprague Dawley rats were used for studying behavioral and oxidative stress markers. ELIZA kits were used to analyse tumour necrosis factor-alpha (TNF-), nuclear factor-B (NF-B), interleukin (IL-18), and pyrin domain-containing protein 3 (NLRP3) expression, while Western blotting was used to measure IL-1 and Caspase-1 expression.

Results

Our findings suggested that altered levels of antioxidant enzymes were associated with elevated levels of TNF-α, NF-B, IL-1, IL-18, Caspase-1, and NLRP3 in the ethanol-treated group. Furthermore, ethanol also caused memory impairment in rats, as measured by behavioural tests. Pretreatment using selected benzimidazole significantly increased the combat of the brain against ethanol-induced oxidative stress. The neuroprotective effects of benzimidazole derivatives were promoted by their free radical scavenging activity, augmentation of endogenous antioxidant proteins (GST, GSH), and amelioration of lipid peroxide (LPO) and other pro-inflammatory mediators. Molecular docking and molecular simulation studies further supported our hypothesis that the synthetic compounds Ca and Cb had an excellent binding affinity with proper bond formation with their targets (TNF-α and NLRP3).

Conclusion

It is revealed that these benzimidazole derivatives can reduce ethanol-induced neuronal toxicity by regulating the expression of cytokines, antioxidant enzymes, and the inflammatory cascade.

Utility of arylglyoxal hydrates in synthesis of 4-aroyl-[1,3,5]triazino[1,2-a]benzimidazol-2(1H)-imines and 5-aryl-2-phenyl-4H-imidazol-4-imines

Nucleophilic substitution reaction for arylglyoxal hydrates (AGs-hydrate) was studied via their reaction with some mono- and multi-nucleophilic reagents in the presence of sodium ethoxide as basic catalyst. Thus, reaction of phenylglyoxal hydrate (1a) with hydrogen sulfide and/or ammonium acetate afforded the corresponding 2-hydroxy-2-mercapto-1-phenylethanone (2) and 2-oxo-2-phenylethanimidamide (3), respectively. Heterocyclization reaction of AGs-hydrate 1a-f with 1-(1H-benzimidazol-2-yl)guanidine (4) gave 4-aroyl-[1,3,5]triazino[1,2-a]benzimidazol-2(1H)-imines 5a-f. Also, a series of 5-aryl-2-phenyl-4H-imidazol-4-imines 7a-d was synthesized via one-pot multicomponent reaction of AGs-hydrate 1a-d, benzonitrile (6) and ammonium acetate. Imidazole-4-imines 7a-d can be also prepared using other route via multicomponent reaction of AGs-hydrate 1a-d, benzenecarboximidamide acetate (8) and ammonium acetate.

Apoptosis inducing properties of 3-biotinylate-6-benzimidazole B-nor-cholesterol analogues

In this work, a series of Biotin-substituted B-nor-cholesteryl benzimidazole compounds were synthesized. The antiproliferativeactivities of these compounds were evaluated in vitro using a series of human cancer cell lines, including HeLa (cervical cancer), SKOV3 (ovarian cancer), T-47D (thymus gland cancer), MCF-7 (human breast cancer) and HEK293T (normal renal epithelial) cells. These compounds displayed distinct antiproliferative activities against the currently tested cancer cells. The apoptotic properties induced by compound 6d were further investigated. Our results showed that compound 6d could induce the apoptosis of SKOV3 cells, blocking the cell growth in S-phase. Western blotting analyses revealed that compound 6d can induce cell apoptosis via the mitochondria-dependent pathway.

Alkylated benzimidazoles: Design, synthesis, docking, DFT analysis, ADMET property, molecular dynamics and activity against HIV and YFV

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New benzimidazole analogs synthesized as antivirals against HIV-1 and yellow fever virus.

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Molecular dynamics simulation studies indicated a stable ligand-protein complex of compound 3a within NNIBP of HIV-RT.

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DFT analysis confirmed the stability of hydrogen bonding interaction between the TRP 229 residue of HIV-RT and compound 3a.

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Molecules were tested for their anti-HIV and broad spectrum antiviral properties against different DNA and RNA viruses.

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Antiviral properties and cytotoxicity determined using MTT assay.

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Compound 3a showed anti-HIV activity and compound 2b showed excellent inhibition property against yellow fever virus.

A series of alkylated benzimidazole derivatives was synthesized and screened for their anti-HIV, anti-YFV, and broad-spectrum antiviral properties. The physicochemical parameters and drug-like properties of the compounds were assessed first, and then docking studies and MD simulations on HIV-RT allosteric sites were conducted to find the possible mode of their action. DFT analysis was also performed to confirm the nature of the hydrogen bonding interaction of active compounds. The in silico studies indicated that the molecules behaved like possible NNRTIs. The nature – polar or non-polar and position of the substituent present at fifth, sixth, and N-1 positions of the benzimidazole moiety played an important role in determining the antiviral properties of the compounds. Among the various compounds, 2-(5,6-dibromo-2-chloro-1H-benzimidazol-1-yl)ethan-1-ol (3a) showed anti-HIV activity with an appreciably low IC₅₀ value as 0.386 × 10⁻⁵μM. Similarly, compound 2b, 3-(2-chloro-5-nitro-1H-benzimidazol-1-yl) propan-1-ol, showed excellent inhibitory property against the yellow fever virus (YFV) with EC₅₀ value as 0.7824 × 10⁻²μM.

1,3,5-Triazine Analogs: A Potent Anticancer Scaffold

Background:

This review presents the exhaustive exploration of 1,3,5-triazine scaffold for development of analogs of anticancer drugs, over the last century. In the recent years, striazine moiety has been one of the most studied moiety, showing broad-spectrum pharmacological activities such as antibacterial, antifungal, analgesic, anti-HIV, antileishmanial, antitrypanosomal, antimalarial and antiviral. Nowadays, many boffins are have become interested in novel synthesis of s-triazine derivatives because of low cost and ease of availability.

Methods:

This scaffold has been extensively investigated mainly in the past decade. Many products have been synthesized from different starting materials and these synthetic products possess anticancer potential against various cell lines.

Results:

Many 1,3,5-triazine analogs exhibited significant anticancer activity in various models and cell lines exhibiting different mechanisms. Some analogs have also shown good pharmacokinetic parameters with less IC50 values.

Conclusion:

Various 1,3,5-triazine analogs have shown potent activities and may be regarded as clinical candidates for future anticancer formulations. This review may be helpful to those researchers seeking required information with regard to the drug design and medicinal properties of 1,3,5-triazine derivatives for selected targets. This review may also offer help to find and improve clinically viable anticancer molecules.

1,3,5-Triazines: A promising scaffold for anticancer drugs development

This review covering literature reports from the beginning of this century to 2016 describes the synthetic pathways, the antitumor activity, the structure-activity relationship and, whenever reported, the possible mechanism of action of 1,3,5-triazine derivatives as well as of their hetero-fused compounds. Many 1,3,5-triazine derivatives, both uncondensed and hetero-fused, have shown remarkable antitumor activities and some of them reached clinical development.

Therapeutic evolution of benzimidazole derivatives in the last quinquennial period

Benzimidazole, a fused heterocycle bearing benzene and imidazole has gained considerable attention in the field of contemporary medicinal chemistry. The moiety is of substantial importance because of its wide array of pharmacological activities. This nitrogen containing heterocycle is a part of a number of therapeutically used agents. Moreover, a number of patents concerning this moiety in the last few years further highlight its worth. The present review covers the recent work published by scientists across the globe during last five years.

Antitumor, antioxidant and antimicrobial studies of substituted pyridylguanidines

A series of N-pivaloyl-N′-(alkyl/aryl)-N″-pyridylguanidine of general formula C₄H₉CONHC(NR¹R²)NPy have been synthesized and characterized using elemental analysis, FT-IR, multinuclear NMR spectroscopy, and in the case of compounds 7 and 11, by single crystal X-ray diffraction (XRD). The synthesized guanidines were tested for antitumor activities against potato tumor, and showed excellent inhibition against Agrobacterium tumefaciens (AT10)-induced tumor. The antioxidant and antimicrobial activities of these new compounds against various bacterial and fungal strains were also investigated.