Synthesis and anticancer activity of novel water soluble benzimidazole carbamates

New tetrahydroisoquinoline-4-carbonitrile derivatives as potent agents against cyclin-dependent kinases, crystal structures, and computational studies

The synthesis of two new hexahydroisoquinoline-4-carbonitrile derivatives (3a and 3b) is reported along with spectroscopic data and their crystal structures. In compound 3a, the intramolecular O-H···O hydrogen bond constraints the acetyl and hydroxyl groups to be syn. In the crystal, inversion dimers are generated by C-H···O hydrogen bonds and are connected into layers parallel to (10-1) by additional C-H···O hydrogen bonds. The layers are stacked with Cl···S contacts 0.17 Å less than the sum of the respective van der Waals radii. The conformation of the compound 3b is partially determined by the intramolecular O-H···O hydrogen bond. A puckering analysis of the tetrahydroisoquinoline unit was performed. In the crystal, O-H···O and C-H···O hydrogen bonds together with C-H···π(ring) interactions form layers parallel to (01-1) which pack with normal van der Waals interactions. To understand the binding efficiency and stability of the title molecules, molecular docking, and 100 ns dynamic simulation analyses were performed with CDK5A1. To rationalize their structure-activity relationship(s), a DFT study at the B3LYP/6-311++G** theoretical level was also done. The 3D Hirshfled surfaces were also taken to investigate the crystal packings of both compounds. In addition, their ADMET properties were explored.Communicated by Ramaswamy H. Sarma.

A Critical Review on Therapeutic Potential of Benzimidazole Derivatives: A Privileged Scaffold

Benzimidazole nucleus is a predominant heterocycle displaying a wide spectrum of pharmacological activities. The privileged nature of the benzimidazole scaffold has been revealed by its presence in most small molecule drugs and in its ability to bind multiple receptors with high affinity. A literature review of the scaffold reveals several instances where structural modifications of the benzimidazole core have resulted in high-affinity lead compounds against a variety of biological targets. Hence, this structural moiety offers opportunities to discover novel, better, safe and highly potent biological agents. The goal of the present review is to compile the medicinal properties of benzimidazole derivatives with a focus on SAR (Structure-Activity Relationships).

Applications of oxetanes in drug discovery and medicinal chemistry

The compact and versatile oxetane motifs have gained significant attention in drug discovery and medicinal chemistry campaigns. This review presents an overview of the diverse applications of oxetanes in clinical and preclinical drug candidates targeting various human diseases, including cancer, viral infections, autoimmune disorders, neurodegenerative conditions, metabolic disorders, and others. Special attention is given to biologically active oxetane-containing compounds and their disease-related targets, such as kinases, epigenetic and non-epigenetic enzymes, and receptors. The review also details the effect of the oxetane motif on important properties, including aqueous solubility, lipophilicity, pKa, P-glycoprotein (P-gp) efflux, metabolic stability, conformational preferences, toxicity profiles (e.g., cytochrome P450 (CYP) suppression and human ether-a-go-go related gene (hERG) inhibition), pharmacokinetic (PK) properties, potency, and target selectivity. We anticipate that this work will provide valuable insights that can drive future discoveries of novel bioactive oxetane-containing small molecules, enabling their effective application in combating a wide range of human diseases.

Cationic N,S-chelate half-sandwich iridium complexes: synthesis, characterization, anticancer and antiplasmodial activity

A series of pyrazole-based ligands and their corresponding cationic N,S-chelate half-sandwich iridium complexes were successfully synthesized. All iridium complexes exhibited good anticancer activity against the MCF-7 and MDA-MB-231 human breast cancer cells. The cytotoxic activity of unsubstituted iridium complex 1 is greater than that of cisplatin against MCF-7 cells. In addition, the cationic half-sandwich iridium complexes are also efficient in antiplasmodial study and complex 1 displayed the best activity as its IC50 was observed to be approximately 0.11 μM against the CQS-NF54 strain. These iridium complexes generally exhibited enhanced activity against the CQS-NF54 strain in comparison with that against the CQR-K1 strain. An "IC50 speed assay" investigation against the CQS-NF54 strain indicated complexes 1-3 to be fast-acting complexes that reach their lowest IC50 values within 16 hours. All complexes were fully characterized by IR spectroscopy, NMR spectroscopy, and elemental analysis, and the structure of the iridium complex was confirmed by single-crystal X-ray diffraction.

Oxetanes in Drug Discovery Campaigns

The oxetane ring is an emergent, underexplored motif in drug discovery that shows attractive properties such as low molecular weight, high polarity, and marked three-dimensionality. Oxetanes have garnered further interest as isosteres of carbonyl groups and as molecular tools to fine-tune physicochemical properties of drug compounds such as pKa, LogD, aqueous solubility, and metabolic clearance. This perspective highlights recent applications of oxetane motifs in drug discovery campaigns (2017-2022), with emphasis on the effect of the oxetane on medicinally relevant properties and on the building blocks used to incorporate the oxetane ring. Based on this analysis, we provide an overview of the potential benefits of appending an oxetane to a drug compound, as well as potential pitfalls, challenges, and future directions.

Synthesis of 1-(2-Hydroxyphenyl)- and (3,5-Dichloro-2-hydroxyphenyl)-5-oxopyrrolidine-3-carboxylic Acid Derivatives as Promising Scaffolds for the Development of Novel Antimicrobial and Anticancer Agents

Increasing antimicrobial resistance among Gram-positive pathogens and pathogenic fungi remains one of the major public healthcare threats. Therefore, novel antimicrobial candidates and scaffolds are critically needed to overcome resistance in Gram-positive pathogens and drug-resistant fungal pathogens. In this study, we explored 1-(2-hydroxyphenyl)-5-oxopyrrolidine-3-carboxylic acid and its 3,5-dichloro-2-hydroxyphenyl analogue for their in vitro antimicrobial activity against multidrug-resistant pathogens. The compounds showed structure-dependent antimicrobial activity against Gram-positive pathogens (S. aureus, E. faecalis, C. difficile). Compounds 14 and 24b showed promising activity against vancomycin-intermediate S. aureus strains, and favorable cytotoxic profiles in HSAEC-1 cells, making them attractive scaffolds for further development. 5-Fluorobenzimidazole, having a 3,5-dichloro-2-hydroxyphenyl substituent, was found to be four-fold, and hydrazone, with a thien-2-yl fragment, was two-fold stronger than clindamycin against methicillin resistant S. aureus TCH 1516. Moreover, hydrazone, bearing a 5-nitrothien-2-yl moiety, showed promising activity against three tested multidrug-resistant C. auris isolates representing major genetic lineages (MIC 16 µg/mL) and azole-resistant A. fumigatus strains harboring TR34/L98H mutations in the CYP51A gene. The anticancer activity characterization demonstrated that the 5-fluorobenzimidazole derivative with a 3,5-dichloro-2-hydroxyphenyl substituent showed the highest anticancer activity in an A549 human pulmonary cancer cell culture model. Collectively these results demonstrate that 1-(2-hydroxyphenyl)-5-oxopyrrolidine-3-carboxylic acid derivatives could be further explored for the development of novel candidates targeting Gram-positive pathogens and drug-resistant fungi.

In Vitro Determination of Antileshmanial Activities of Benzimidazolium Derivatives on L. major Promastigotes and Amastigotes

PURPOSE

Leishmaniasis is a serious public health problem infecting millions of people worldwide. An effective and reliable treatment method to be used in the treatment of the disease has not been developed yet.

METHODS

In this article, the anti-leishmanial activities of two benzimidazolium derivatives (B.A and B.B) against Leishmania major promastigotes and amastigotes, which are known to cause cutaneous leishmaniasis, were investigated for the first time. The immunostimulatory activity of the developed formulations was determined using the J774 murine macrophage cell line.

RESULTS

B.A and B.B compounds were found to have a much higher cytotoxic effect than Amphotericin B (IC₅₀ value 0.75 μM ± 0.03), which is used as the reference drug. The IC₅₀ value was determined as 2.02 µM ± 0.52 for B.A and 1.83 µM ± 0.71 for B.B in Leishmania promastigotes. In addition, IC₅₀ values of B. A and B.B Leishmania amastigotes were found to be 1.01 µM and 0.67 µM, respectively. It was found that B.B was 81.12 times more selective than Amphotericin B and showed the highest selectivity against L. major promastigotes (359.09) and amastigotes (980.80). Considering the selectivity indices (SI) of B.A and B.B, both compounds tested are more promising than Amphotericin B.

CONCLUSION

The results showed that benzimidazolium derivatives have anti-leishmanial potential against L. major, which is the causative agent of cutaneous leishmaniasis. Thus, we can say that the obtained results will help the development of effective and safe antileishmanial drug formulations against cutaneous leishmaniasis.

Biologically Potent Benzimidazole-Based-Substituted Benzaldehyde Derivatives as Potent Inhibitors for Alzheimer's Disease along with Molecular Docking Study

Twenty-one analogs were synthesized based on benzimidazole, incorporating a substituted benzaldehyde moiety (1-21). These were then screened for their acetylcholinesterase and butyrylcholinesterase inhibition profiles. All the derivatives except 13, 14, and 20 showed various inhibitory potentials, ranging from IC50 values of 0.050 ± 0.001 µM to 25.30 ± 0.40 µM against acetylcholinesterase, and 0.080 ± 0.001 µM to 25.80 ± 0.40 µM against butyrylcholinesterase, when compared with the standard drug donepezil (0.016 ± 0.12 µM and 0.30 ± 0.010 µM, against acetylcholinesterase and butyrylcholinesterase, respectively). Compound 3 in both cases was found to be the most potent compound due to the presence of chloro groups at the 3 and 4 positions of the phenyl ring. A structure-activity relationship study was performed for all the analogs except 13, 14, and 20, further, molecular dynamics simulations were performed for the top two compounds as well as the reference compound in a complex with acetylcholinesterase and butyrylcholinesterase. The molecular dynamics simulation analysis revealed that compound 3 formed the most stable complex with both acetylcholinesterase and butyrylcholinesterase, followed by compound 10. As compared to the standard inhibitor donepezil both compounds revealed greater stabilities and higher binding affinities for both acetylcholinesterase and butyrylcholinesterase.

Inhibition of Wnt Signaling in Colon Cancer Cells via an Oral Drug that Facilitates TNIK Degradation

We have synthesized an oxetane derivative of the benzimidazole compound mebendazole (OBD9) with enhanced solubility and strong anticancer activity in multiple types of cancer cells, especially colorectal cancer. In this report, we provide evidence that OBD9 suppresses colorectal cancer growth by interfering with the Wnt signaling pathway, a main driver of cell growth in colorectal cancer. Specifically, we find that OBD9 induces autophagic degradation of TNIK (traf2 and Nck-interacting kinase), which promotes T-cell factor-4 (TCF4)/beta-catenin-mediated gene expression. Thus, OBD9 as a TNIK inhibitor blocks Wnt/beta-catenin signaling at the final step of transcriptional activation. We suggest that OBD9 provides a potential novel autophagy-mediated, Wnt-damping therapeutic strategy for the treatment of colorectal cancer.

Novel 1,2,5-Trisubstituted Benzimidazoles Potentiate Apoptosis by Mitochondrial Dysfunction in Panel of Cancer Cells

Synthetic small molecules have been very effective in decimating cancer cells by targeting various aberrantly overexpressed oncogenic proteins. These small molecules target proteins involved in cell cycle regulation, cell division, migration, invasion, angiogenesis, and other regulatory proteins to induce apoptosis in cancer cells. In this study, we have synthesized a novel 1,2,5-trisubstituted benzimidazole chemical library of small molecules and unveiled their anticancer potential against a panel of cancer cell lines such as Jurkat, K-562, MOLT-4, HeLa, HCT116, and MIA PaCa-2 cancer cells. The MTT assay and Trypan blue dye exclusion assay clearly unveiled the cytotoxic effect of methyl 1-benzyl-2-(4-fluoro-3-nitrophenyl)-1H-benzo[d]imidazole-5-carboxylate (TJ08) and its potential to induce apoptosis with effective IC₅₀ of 1.88 ± 0.51, 1.89 ± 0.55, 2.05 ± 0.72, 2.11 ± 0.62, 3.04 ± 0.8, and 3.82 ± 0.25 μM against Jurkat, K562, MOLT-4, HeLa, HCT116, and MIA PaCa-2 cancer cell lines, respectively. Altered mitochondrial membrane potential was observed in HeLa, HCT116, and Jurkat cells due to TJ08 treatment, which was unveiled by JC10 staining. Induction of early and late apoptosis by TJ08 treatment was also unveiled by apoptotic analysis and immunofluorescence imaging. Cell cycle analysis distribution confirms the accumulation of cells in the S-phase in a dose-dependent manner.

New Benzimidazoles Targeting Breast Cancer: Synthesis, Pin1 Inhibition, 2D NMR Binding, and Computational Studies

Benzimidazole derivatives are known to be key players in the development of novel anticancer agents. Herein, we aimed to synthesize novel derivatives to target breast cancer. A new series of benzimidazole derivatives conjugated with either six- and five-membered heterocyclic ring or pyrazanobenzimidazoles and pyridobenzimidazole linkers were synthesized yielding compounds 5–8 and 10–14, respectively. Structure elucidation of the newly synthesized compounds was achieved through microanalytical analyses and different spectroscopic techniques (¹H, ¹³C-APT and ¹H–¹H COSY and IR) in addition to mass spectrometry. A biological study for the newly synthesized compounds was performed against breast cancer cell lines (MCF-7), and the most active compounds were further subjected to normal Human lung fibroblast (WI38) which indicates their safety. It was found that most of them exhibit high cytotoxic activity against breast cancer (MCF-7) and low cytotoxic activity against normal (WI38) cell lines. Compounds 5, 8, and 12, which possess the highest anti-breast cancer activity against the MCF-7 cell line, were selected for Pin1 inhibition assay using tannic acid as a reference drug control. Compound 8 was examined for its effect on cell cycle progression and its ability to apoptosis induction. Mechanistic evaluation of apoptosis induction was demonstrated by triggering intrinsic apoptotic pathways via inducing ROS accumulation, increasing Bax, decreasing Bcl-2, and activation of caspases 6, 7, and 9. Binding to 15N-labeled Pin1 enzyme was performed using state-of-the-art ¹⁵N–¹H HSQC NMR experiments to describe targeting breast cancer on a molecular level. In conclusion, the NMR results demonstrated chemical shift perturbation (peak shifting or peak disappearance) upon adding compound 12 indicating potential binding. Molecular docking using ‘Molecular Operating Environment’ software was extremely useful to elucidate the binding mode of active derivatives via hydrogen bonding.

Synthesis and evaluation of carbamate derivatives as fatty acid amide hydrolase and monoacylglycerol lipase inhibitors

Fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) are the primary catabolic enzymes for endocannabinoids, anandamide (AEA), and 2-arachidonoyl glycerol. Numerous studies have shown that FAAH and MAGL play an important role in modulating various central nervous system activities; hence, the development of small molecule FAAH/MAGL inhibitors is an active area of research. Several small molecules possessing the carbamate scaffold are documented as potential FAAH/MAGL inhibitors. Here, we designed and synthesized a series of open chain and cyclic carbamates and evaluated their dual FAAH-MAGL inhibition properties. Phenyl [4-(piperidin-1-ylmethyl)phenyl]carbamate (2e) emerged as the most potent MAGL inhibitor (IC₅₀  = 19 nM), benzyl (1H-benzo[d]imidazol-2-yl)carbamate (3h) was the most potent FAAH inhibitor (IC₅₀  = 55 nM), and phenyl (6-fluorobenzo[d]thiazol-2-yl)carbamate (2i) egressed as a nonselective dual FAAH-MAGL inhibitor (FAAH: 82 nM, MAGL: 72 nM). The enzyme kinetics experiments revealed that the compounds inhibit FAAH/MAGL in a covalent-reversible manner, with a mixed binding mode of action. Moreover, the lead compounds were found suitable for blood-brain permeation in the parallel artificial membrane permeation assay. Furthermore, docking simulation experiments suggested that the potency of the lead compounds was governed by hydrogen bonds and hydrophobic interactions with the enzyme active sites. In silico drug-likeness and ADMETox prediction studies provided useful information on the compounds' oral absorption, metabolism, and toxicity profiles. In summary, this study afforded potent multifunctional carbamates with appreciable pharmacokinetic profiles meriting further investigation.

Oxygen- and Sulphur-Containing Heterocyclic Compounds as Potential Anticancer Agents

Oxygen- and sulphur-based heterocycles form the core structure of many biologically active molecules as well as U.S. FDA-approved drugs. Moreover, they possess broad range of biological activities, viz. anticancer, antiinflammatory, antioxidant, antitumour, antibacterial, antiviral, antidiabetic, anticonvulsant, anti-tubercular, analgesic, anti-leishmanial, antimalarial, antifungal, and anti-histaminic, Hence, O- and S-based heterocycles are gaining more attention in recent years on the road to the discovery of innovative anticancer drugs after the extensive investigation of nitrogen-based heterocycles as anticancer agents. Several attempts have been made to synthesize fused oxygen- and sulphur-based heterocyclic derivatives as joining one heterocyclic moiety with another may lead to improvement in the biological profile of a molecule. Humans have been cursed with cancer since long time. Despite the development of several heterocyclic anticancer medications such as 5-fluorouracil, doxorubicin, methotrexate, and daunorubicin, cure of cancer is difficult. Hence, researchers are trying to synthesize new fused/spiro heterocyclic molecules to discover novel anticancer drugs which may show promising anticancer effects with fewer side effects. Furthermore, fused heterocycles behave as DNA intercalating agents which have the ability to interact with DNA, leading to cell death thereby exerting anticancer effect. This review article highlights the synthesis and anticancer potentiality of oxygen- and sulphur-containing heterocyclic compounds covering the period from 2011 to 2021.

Synthesis of Benzimidazole-Sulfonyl Derivatives and Their Biological Activities

Currently, the synthesis of new compounds with potential bioactivities has become a central issue in the drug discovery arena. Among these new compounds, benzimidazole-sulfonyl scaffolds have vital applications in the fields of pharmaceuticals industries. Benzimidazole and sulfonyl compounds have remarkable biological activities, such as antibacterial, antifungal, anti-inflammatory, antiproliferative, carbonic anhydrase inhibitory, and α-amylase inhibitory activities. Furthermore, recent literature mentions the synthesis and bioactivities of some benzimidazole-sulfonyl hybrids. In this review, we focus on reviewing the synthesis of these hybrid scaffolds and their various types of biological activities of the compounds.

Benzimidazole-carbamate anthelmintics: Perspective candidates for the anticancer drug development

Cellular oncogenesis involves a complex interplay between the several synchronized, interdependent pathways that collectively determine the pathogenesis and pathophysiology of cancer. Limited therapeutic success with the existing anticancer drugs drew huge interest in the design and development of new pharmacophores with improved clinical efficacy, however despite huge investments in anticancer RD; the average number of Food and Drug Administration-approved anticancer drugs declined since the 1990s. The contemporary anticancer medications possess high attrition rates, bear substantial costs, and experience low efficacy owing to the drug resistance expressed by the aggressive tumors. Mainly, the translation of novel candidate anticancer drugs into clinical practice, their commercialization, and transformation from the bench to bedside require a long timeframe of 10-15 years and capital worth millions of dollars. The repurposing strategy substantially accelerated the anticancer drug development regime as the approved drugs with tested safety and efficacy ensure a minimal risk of failure, and nominal R&D expenses as anticipated for the newly identified candidate drugs yet to enter the clinical trials. In addition, the repurposed drugs ensure a rapid clinical translation due to a validated clinical profile and their ability to target the identified hallmarks and hitherto unknown vulnerabilities of cancer. The flagship project "Repurposing Drugs in Oncology" (ReDO) identified 268 "hard repurposing" noncancer medications as candidate drugs with a promising anticancer profile (https://www.anticancerfund.org/en/redo-db). However, the generic profile of 84% of repurposed drugs in ReDO data set discourages the commercial sponsors from funding the repurposing trials, especially the Phase III efficacy trials that require significant capital.

New Benzimidazole-, 1,2,4-Triazole-, and 1,3,5-Triazine-Based Derivatives as Potential EGFRWT and EGFRT790M Inhibitors: Microwave-Assisted Synthesis, Anticancer Evaluation, and Molecular Docking Study

A new series of benzimidazole, 1,2,4-triazole, and 1,3,5-triazine derivatives were designed and synthesized using a microwave irradiation synthetic approach utilizing 2-phenylacetyl isothiocyanate (1) as a key starting material. All the new analogues were evaluated as anticancer agents against a panel of cancer cell lines utilizing doxorubicin as a standard drug. Most of the tested derivatives exhibited selective cytotoxic activity against MCF-7 and A-549 cancer cell lines. Furthermore, the new target compounds 5, 6, and 7 as the most potent antiproliferative agents have been assessed as in vitro EGFR^WT and EGFR^T790M inhibitors compared to the reference drugs erlotinib and AZD9291. They represented more potent suppression activity against the mutated EGFR^T790M than the wild-type EGFR^WT. Moreover, the compounds 5, 6, and 7 down-regulated the oncogenic parameter p53 ubiquitination. A docking simulation of compound 6b was carried out to correlate its molecular structure with its significant EGFR inhibition potency and its possible binding interactions within the active site of EGFR^WT and the mutant EGFR^T790M.

Synthesis and antitumor activity of novel silibinin and 2,3-dehydrosilybin derivatives with carbamate groups

A novel series of silibinin and 2,3-dehydrosilybin derivatives bearing carbamate groups were designed, synthesized and their in vitro anticancer activities were screened against human cancer cell lines including MCF-7, NCI-H1299, HepG2 and HT29 by CCK-8 assay. The results showed that most of the compounds significantly suppressed the proliferation of tested cancer cells. Among them, compounds 2h, 3h and 3f demonstrated markedly higher antiproliferative activity on MCF-7 cells with IC₅₀ values of 2.08, 5.54 and 6.84 µM, respectively. Compounds 3e, 3g and 2g displayed better cytotoxic activity against NCI-H1299 cells with IC₅₀ values of 8.07, 8.45 and 9.09 µM, respectively. Compounds 3g, 3c and 3h exhibited a promising inhibitory effect against HepG2 cells with IC₅₀ values of 8.88, 9.47 and 9.99 µM, respectively. Compounds 3e, 2e and 3c revealed effective biological potency on HT29 cells with IC₅₀ values of 6.27, 9.13 and 9.32 µM, respectively. In addition, the outcomes of the docking studies between compounds 2f, 2h, 3e, 3g and Hsp90 receptor (PDB ID: 4AWO) suggest the possible mechanism of inhibition against MCF-7 cell lines.

Formulating The Structural Aspects Of Various Benzimidazole Cognates

BACKGROUND

Benzimidazole derivatives are widely used in clinical practice as potential beneficial specialists. Recently, the neuroprotective effect of derivatives of benzimidazole moiety has also shown positive outcomes.

OBJECTIVE

To develop favourable molecules for various neurodegenerative disorders using the versatile chemical behaviour of the benzimidazole scaffold.

METHODS

About 25 articles were collected that discussed various benzimidazole derivatives and categorized them under various subheadings based on the targets such as BACE 1, JNK, MAO, choline esterase enzyme, oxidative stress, mitochondrial dysfunction in which they act. The structural aspects of various benzimidazole derivatives were also studied.

CONCLUSION

To manage various neurodegenerative disorders, a multitargeted approach will be the most hopeful stratagem. Some benzimidazole derivatives can be considered for future studies, which are mentioned in the discussed articles.

A Comprehensive Account on Recent Progress in Pharmacological Activities of Benzimidazole Derivatives

Nowadays, nitrogenous heterocyclic molecules have attracted a great deal of interest among medicinal chemists. Among these potential heterocyclic drugs, benzimidazole scaffolds are considerably prevalent. Due to their isostructural pharmacophore of naturally occurring active biomolecules, benzimidazole derivatives have significant importance as chemotherapeutic agents in diverse clinical conditions. Researchers have synthesized plenty of benzimidazole derivatives in the last decades, amidst a large share of these compounds exerted excellent bioactivity against many ailments with outstanding bioavailability, safety, and stability profiles. In this comprehensive review, we have summarized the bioactivity of the benzimidazole derivatives reported in recent literature (2012-2021) with their available structure-activity relationship. Compounds bearing benzimidazole nucleus possess broad-spectrum pharmacological properties ranging from common antibacterial effects to the world's most virulent diseases. Several promising therapeutic candidates are undergoing human trials, and some of these are going to be approved for clinical use. However, notable challenges, such as drug resistance, costly and tedious synthetic methods, little structural information of receptors, lack of advanced software, and so on, are still viable to be overcome for further research.

Discovery of new 2-phenyl-1H-benzo[d]imidazole core-based potent α-glucosidase inhibitors: Synthesis, kinetic study, molecular docking, and in vivo anti-hyperglycemic evaluation

In the present study, a series of 2-phenyl-1H-benzo[d]imidazole-based α-glucosidase inhibitors were synthesized and evaluated for their in vitro and in vivo anti-diabetic potential. Screening of an in-house library revealed a moderated α-glucosidase inhibitor, 6a with 3-(1H-benzo[d]imidazol-2-yl)aniline core, and then the structural optimization was performed to obtain more efficient derivatives. Most of these derivatives showed increased activity than 6a, and the most promising inhibitors were found to be compounds 15o and 22d with IC₅₀ values of 2.09 ± 0.04 and 0.71 ± 0.02 µM, respectively. Fluorescence quenching experiment confirmed the direct binding of compounds 15o and 22d with α-glucosidase. Kinetic study revealed that both compounds were non-competitive inhibitors, that was consistent with the result of molecular docking studies where they located at the allosteric site of the enzyme. Cell viability evaluation demonstrated the non-cytotoxicity of 15o and 22d against LO2 cells. Furthermore, the in vivo pharmacodynamic study revealed that compound 15o showed significant hypoglycemic activity and improved oral sucrose tolerance, comparable to the positive control acarbose.

3-Alkenyl-2-oxindoles: Synthesis, antiproliferative and antiviral properties against SARS-CoV-2

Sets of 3-alkenyl-2-oxindoles (6,10,13) were synthesized in a facile synthetic pathway through acid dehydration (EtOH/HCl) of the corresponding 3-hydroxy-2-oxoindolines (5,9,12). Single crystal (10a,c) and powder (12a,26f) X-ray studies supported the structures. Compounds 6c and 10b are the most effective agents synthesized (about 3.4, 3.3 folds, respectively) against PaCa2 (pancreatic) cancer cell line relative to the standard reference used (Sunitinib). Additionally, compound 10b reveals antiproliferative properties against MCF7 (breast) cancer cell with IC₅₀ close to that of Sunitinib. CAM testing reveals that compounds 6 and 10 demonstrated qualitative and quantitative decreases in blood vessel count and diameter with efficacy comparable to that of Sunitinib, supporting their anti-angiogenic properties. Kinase inhibitory properties support their multi-targeted inhibitory activities against VEGFR-2 and c-kit in similar behavior to that of Sunitinib. Cell cycle analysis studies utilizing MCF7 exhibit that compound 6b arrests the cell cycle at G1/S phase while, 10b reveals accumulation of the tested cell at S phase. Compounds 6a and 10b reveal potent antiviral properties against SARS-CoV-2 with high selectivity index relative to the standards (hydroxychloroquine, chloroquine). Safe profile of the potent synthesized agents, against normal cells (VERO-E6, RPE1), support the possible development of better hits based on the attained observations.

Synthesis of Antimicrobial Benzimidazole-Pyrazole Compounds and Their Biological Activities

The synthesis of new compounds with antimicrobial and antiviral properties is a central objective today in the context of the COVID-19 pandemic. Benzimidazole and pyrazole compounds have remarkable biological properties, such as antimicrobial, antiviral, antitumor, analgesic, anti-inflammatory, anti-Alzheimer's, antiulcer, antidiabetic. Moreover, recent literature mentions the syntheses and antimicrobial properties of some benzimidazole-pyrazole hybrids, as well as other biological properties thereof. In this review, we aim to review the methods of synthesis of these hybrids, the antimicrobial activities of the compounds, their correlation with various groups present on the molecule, as well as their pharmaceutical properties.

Recent advancements on Benzimidazole: A versatile scaffold in medicinal chemistry

Benzimidazole is nitrogen containing fused heterocycle which has been extensively explored in medicinal chemistry. Benzimidizole nucleus has been found to possess various biological activities such as anticancer, antimicrobial, anti-inflammatory, antiviral, antitubercular and antidiabetic. A number of benzimidazoles such as bendamustine, pantoprazole have been approved for the treatment of various illnesses whereas galeterone and GSK461364 are in clinical trials. The present review article gives an overview about the different biological activities exhibited by the benzimidazole derivatives as well as different methods used for the synthesis of benzimidazole derivatives for the past ten years.

Unbiased Phenotype-Based Screen Identifies Therapeutic Agents Selective for Metastatic Prostate Cancer

In American men, prostate cancer is the second leading cause of cancer-related death. Dissemination of prostate cancer cells to distant organs significantly worsens patients' prognosis, and currently there are no effective treatment options that can cure advanced-stage prostate cancer. In an effort to identify compounds selective for metastatic prostate cancer cells over benign prostate cancer cells or normal prostate epithelial cells, we applied a phenotype-based in vitro drug screening method utilizing multiple prostate cancer cell lines to test 1,120 different compounds from a commercial drug library. Top drug candidates were then examined in multiple mouse xenograft models including subcutaneous tumor growth, experimental lung metastasis, and experimental bone metastasis assays. A subset of compounds including fenbendazole, fluspirilene, clofazimine, niclosamide, and suloctidil showed preferential cytotoxicity and apoptosis towards metastatic prostate cancer cells in vitro and in vivo. The bioavailability of the most discerning agents, especially fenbendazole and albendazole, was improved by formulating as micelles or nanoparticles. The enhanced forms of fenbendazole and albendazole significantly prolonged survival in mice bearing metastases, and albendazole-treated mice displayed significantly longer median survival times than paclitaxel-treated mice. Importantly, these drugs effectively targeted taxane-resistant tumors and bone metastases - two common clinical conditions in patients with aggressive prostate cancer. In summary, we find that metastatic prostate tumor cells differ from benign prostate tumor cells in their sensitivity to certain drug classes. Taken together, our results strongly suggest that albendazole, an anthelmintic medication, may represent a potential adjuvant or neoadjuvant to standard therapy in the treatment of disseminated prostate cancer.

Simple and green synthesis of benzimidazoles and pyrrolo[1,2-a]quinoxalines via Mamedov heterocycle rearrangement

This method is metal and catalyst-free and only solvent (HOAc) is required with H₂O as the sole byproduct.

Synthesis, density functional theory study and in vitro antimicrobial evaluation of new benzimidazole Mannich bases

The tri-component synthesis of novel chiral benzimidazole Mannich bases, by reaction between benzimidazole, aqueous 30% formaldehyde and an amine, the biological evaluation and DFT studies of the new compounds are reported here. The ¹H-NMR, ¹³C-NMR, FTIR spectra and elemental analysis confirm the structures of the new compounds. All synthesized compounds were screened by qualitative and quantitative methods for their in vitro antibacterial activity against 4 bacterial strains. DFT studies were accomplished using GAMESS 2012 software and HOMO-LUMO analysis allowed the calculation of electronic and structural parameters of the chiral Mannich bases. The geometry of 1-methylpiperazine, the cumulated Mullikan atomic charges of the two heteroatoms and of the methyl, and the value of the global electrophilicity index (ω = 0.0527) of the M-1 molecule is correlated with its good antimicrobial activity. It was found that the presence of saturated heterocycles from the amine molecule, 1-methyl piperazine and morpholine, respectively, contributes to an increased biological activity, compared to aromatic amino analogs, diphenylamino-, 4-nitroamino- and 4-aminobenzoic acid. The planarity of the molecules, specific bond lengths and localization of HOMO-LUMO orbitals is responsible for the best biological activities of the compounds.

Design, synthesis, biological evaluation, QSAR analysis and molecular modelling of new thiazol-benzimidazoles as EGFR inhibitors

Heterocyclic rings such as thiazole and benzimidazole are considered as privileged structures, since they constitute several FDA-approved drugs for cancer treatment. In this work, a new set of 2-(2-(substituted) hydrazinyl)-4-(1-methyl-1H-benzo[d]imidazol-2-yl) thiazoles 4a-q were designed as epidermal growth factor receptor (EGFR) inhibitors and synthesized using concise synthetic methods. The new target compounds have been evaluated in vitro for their suppression activity against EGFR TK. Compounds 4n, 4h, 4i, 4a and 4d exhibited significant potency in comparison with erlotinib which served as a reference drug (IC50, 71.67-152.59 nM; IC50 erlotinib, 152.59 nM). Furthermore, MTT assay revealed that compounds 4j, 4a, 4f, 4h, 4n produced the most promising cytotoxic potency against the human breast cancer cell line (MCF-7) (IC50; 5.96-11.91 µM; IC50 erlotinib; 4.15 µM). Compound 4a showed promising activity as EGFR TK inhibitor as well as anti-breast cancer agent. In addition, 4a induced apoptotic effect and cell cycle arrest at G2/M phase preventing the mitotic cycle in MCF-7 cells. Moreover, 4a upregulated the oncogenic parameters; caspase-3, p53, Bax/Bcl-2 as well as it inhibited the level of PARP-1 enzyme. QSAR study was carried out for the new derivatives and it revealed the goodness of the models. Furthermore, molecular docking studies represented the binding modes of the promising compounds in the active pocket of EGFR.

Synthesis, state-of-the-art NMR-binding and molecular modeling study of new benzimidazole core derivatives as Pin1 inhibitors: Targeting breast cancer

New series of benzimidazole ring core conjugated with either dithiocarbamate or thiopropyl linkers, hybridized with different secondary amines were synthesized; 5-15 and 22-31; respectively. The new compounds were characterized by different spectroscopic techniques (¹H, ¹³C 1D & 2D NMR, ESI-MS and IR). They were screened for in vitro anticancer activity against breast cancer using MCF7 cell line. The results obtained revealed that compounds 5, 12, 15 and 25 were the most active among the synthesized series exhibiting IC₅₀ < 10 µg/ml against DOX. To characterize targeting breast cancer on molecular level, binding to ¹⁵N-labeled Pin1 enzyme was conducted using state-of-the-art 2D NMR binding experiments. Results showed promising binding between compounds 5, 12, and 25 by chemical shift perturbation (peak shifting or peak disappearance). Molecular docking study were quite valuable to explain the binding mode of active derivatives via hydrogen bonding. Additional contact preferences and surface mapping studies stated the similarity pattern between active candidates which may pave the way for more precise anti breast cancer target optimization.

The Azoles in Pharmacochemistry: Perspectives on the Synthesis of New Compounds and Chemoinformatic Contributions

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Due to their versatile biological activity, Azoles are widely studied in pharmacochemistry. It is possible to use them in many applications and in studies aimed at discovering antiparasitic, antineoplastic, antiviral, antimicrobial compounds; and in the production of materials for treatment of varied pathologies. Based on their biological activity, our review presents several studies that involve this class of organic compounds. A bibliographic survey of this type can effectively contribute to pharmaceutical sciences, stimulating the discovery of new compounds, and structural improvements to biological profiles of interest. In this review, articles are discussed involving the synthesis of new compounds and chemoinformatic contributions. Current applications of azoles in both the pharmaceutical and agri-business sectors are well known, yet as this research highlights, azole compounds can also bring important contributions to the fight against many diseases. Among the heterocyclics, azoles are increasingly studied by research groups around the world for application against tuberculosis, HIV, fungal and bacterial infections; and against parasites such as leishmaniasis and trypanosomiasis. Our hope is that this work will help arouse the interest of research groups planning to develop new bioactives to fight against these and other diseases.

Synthesis and antiproliferative activity of benzimidazole-based, trinuclear neutral cyclometallated and cationic, N^N-chelated ruthenium(ii) complexes

A series of 2-phenyl and 2-pyridyl tris-benzimidazole ligands was reacted with the [Ru(p-cymene)Cl₂]₂ dimer to yield the corresponding neutral cyclometallated and cationic trinuclear organoruthenium(ii) complexes.

Toxicological effects of some antiparasitic drugs on equine liver glutathione S-Transferase enzyme activity

Benzimidazoles are antiparasitic drugs having an extensive application field like agriculture, medicine, and especially in veterinary medicine. In this study, we report the effect of some benzimidazole drugs such as ricobendazole (RBZ), thiabendazole (TBZ), albendazole (ALBA) and oxfendazole (OFZ) on glutathione s-transferase (GST) enzyme activity. The kinetics studies, IC₅₀ and Ki values of the tested drugs on GSTs enzyme activity were investigated. The obtained ranking of IC₅₀ values were found to be approximately RBZ (53.31 μM, r^2: 0.9778) < OFZ (57.75 μM, r^2: 0.9630) < ALBA (63.00 μM, r^2: 0.9443) < TBZ (69.30 μM, r^2: 0.9491). And the obtained ranking of Ki values of the tested drugs (RBZ, TBZ, ALBA, and OFZ) for GSTs enzyme activity was found to be approximately 26.37 ± 2.96, 44.01 ± 5.74, 39.82 ± 3.98 and 30.14 ± 3.03 μM, respectively. Experimental results showed that tested the benzimidazoles drugs have some significant inhibitory effect on GSTs enzyme activity. And also, it was determined that RBZ, ALBA, OFZ are competitive inhibition, but TBZ is non-competitive inhibitors on GSTs enzyme activity. RBZ drug showed the best inhibitory effect with the lowest Ki value.