Design, synthesis and biological evaluation of novel benzimidazole-2-substituted phenyl or pyridine propyl ketene derivatives as antitumour agents

Design and synthesis of novel coumarin-benzimidazole hybrids as human galectin-1 inhibitors

Aim: To develop novel non-carbohydrate inhibitors of human galectin-1 (GAL-1), we have designed a series of coumarin-benzimidazole hybrids. Methods: We synthesized and characterized the coumarin-benzimidazole hybrids and further evaluated them using an in vitro GAL-1 enzyme-linked immunosorbent assay and in silico methods. Results: Among all, the compounds 6p and 6q were found to be potent, with GAL-1 inhibition of 37.61 and 36.92%, respectively, at 10 μM in GAL-1-expressed cell culture supernatant of MCF-7 cells. These two compounds are feasible for fluorine-18 radiolabeling to develop GAL-1 selective PET radiotracers. Computational studies revealed strong binding interactions of GAL-1 with these novel coumarin-benzimidazole hybrids. Conclusion: Coumarin-benzimidazole hybrids can serve as potential leads to develop selective non-carbohydrate GAL-1 inhibitors for cancer therapy.

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).

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.

Reinvestigation of Passerini and Ugi scaffolds as multistep apoptotic inducers via dual modulation of caspase 3/7 and P53-MDM2 signaling for halting breast cancer

Selective induction of breast cancer apoptosis is viewed as the mainstay of various ongoing oncology drug discovery programs. Passerini scaffolds have been recently exploited as selective apoptosis inducers via a caspase 3/7 dependent pathway. Herein, the optimized Passerini caspase activators were manipulated to synergistically induce P53-dependent apoptosis via modulating the closely related P53-MDM2 signaling axis. The adopted design rationale and synthetic routes relied on mimicking the general thematic features of lead MDM2 inhibitors incorporating multiple aromatic rings. Accordingly, the cyclization of representative Passerini derivatives and related Ugi compounds into the corresponding diphenylimidazolidine and spiro derivative was performed, resembling the nutlin-based and spiro MDM-2 inhibitors, respectively. The study was also extended to explore the apoptotic induction capacity of the scaffold after simplification and modifications. MTT assay on MCF-7 and MDA-MB231 breast cancer cells compared to normal fibroblasts (WI-38) revealed their promising cytotoxic activities. The flexible Ugi derivatives 3 and 4, cyclic analog 8, Passerini adduct 12, and the thiosemicarbazide derivative 17 were identified as the study hits regarding cytotoxic potency and selectivity, being over 10-folds more potent (IC50 = 0.065-0.096 μM) and safer (SI = 4.4-18.7) than doxorubicin (IC50 = 0.478 μM, SI = 0.569) on MCF-7 cells. They promoted apoptosis induction via caspase 3/7 activation (3.1-4.1 folds) and P53 induction (up to 4 folds). Further apoptosis studies revealed that these compounds enhanced gene expression of BAX by 2 folds and suppressed Bcl-2 expression by 4.29-7.75 folds in the treated MCF-7 cells. Docking simulations displayed their plausible binding modes with the molecular targets and highlighted their structural determinants of activities for further optimization studies. Finally, in silico prediction of the entire library was computationally performed, showing that most of them could be envisioned as drug-like candidates.

Rational Design, Synthesis, Separation, and Characterization of New Spiroxindoles Combined with Benzimidazole Scaffold as an MDM2 Inhibitor

Rational design for a new spiroxindoles, combined with a benzimidazole scaffold to identify a new murine double minute two (MDM2) inhibitor was synthesized and characterized. The desired spiroxindoles were achieved via a [3+2] cycloaddition reaction approach which afforded the cycloadducts with four asymmetric centers separated in an excellent regioselective and diastereoselective compound. The separated spiroxindoles were subjected to a set of biochemical assays including an NCI cell panel assay, MTT assay, and MDM2 binding analysis by a microscale thermophoresis assay. The anticancer reactivity for the tested compounds showed IC50 (µM) in the range between 3.797–6.879 µM, and compound 7d with IC50 = 3.797 ± 0.205 µM was the most active candidate between the series. The results showed promising results that identified that compound 7a could be inhibited the MDM2 with KD = 2.38 μm. Compound 7a developed a network of interactions with the MDM2 receptor studied in silico by molecular docking.

Nitrogen Containing Heterocycles as Anticancer Agents: A Medicinal Chemistry Perspective

Cancer is one of the major healthcare challenges across the globe. Several anticancer drugs are available on the market but they either lack specificity or have poor safety, severe side effects, and suffer from resistance. So, there is a dire need to develop safer and target-specific anticancer drugs. More than 85% of all physiologically active pharmaceuticals are heterocycles or contain at least one heteroatom. Nitrogen heterocycles constituting the most common heterocyclic framework. In this study, we have compiled the FDA approved heterocyclic drugs with nitrogen atoms and their pharmacological properties. Moreover, we have reported nitrogen containing heterocycles, including pyrimidine, quinolone, carbazole, pyridine, imidazole, benzimidazole, triazole, β-lactam, indole, pyrazole, quinazoline, quinoxaline, isatin, pyrrolo-benzodiazepines, and pyrido[2,3-d]pyrimidines, which are used in the treatment of different types of cancer, concurrently covering the biochemical mechanisms of action and cellular targets.

Anticancer effects of licochalcones: A review of the mechanisms

Cancer is a disease with a high fatality rate representing a serious threat to human health. Researchers have tried to identify effective anticancer drugs. Licorice is a widely used traditional Chinese medicine with various pharmacological properties, and licorice-derived flavonoids include licochalcones like licochalcone A, licochalcone B, licochalcone C, licochalcone D, licochalcone E, and licochalcone H. By regulating the expression in multiple signaling pathways such as the EGFR/ERK, PI3K/Akt/mTOR, p38/JNK, JAK2/STAT3, MEK/ERK, Wnt/β-catenin, and MKK4/JNK pathways, and their downstream proteins, licochalcones can activate the mitochondrial apoptosis pathway and death receptor pathway, promote autophagy-related protein expression, inhibit the expression of cell cycle proteins and angiogenesis factors, regulate autophagy and apoptosis, and inhibit the proliferation, migration, and invasion of cancer cells. Among the licochalcones, the largest number of studies examined licochalcone A, far more than other licochalcones. Licochalcone A not only has prominent anticancer effects but also can be used to inhibit the efflux of antineoplastic drugs from cancer cells. Moreover, derivatives of licochalcone A exhibit strong antitumor effects. Currently, most results of the anticancer effects of licochalcones are derived from cell experiments. Thus, more clinical studies are needed to confirm the antineoplastic effects of licochalcones.

Novel spirooxindole based benzimidazole scaffold: In vitro, nanoformulation and in vivo studies on anticancer and antimetastatic activity of breast adenocarcinoma

The present work provided in vitro anticancer investigation of novel spirooxindole based benzimidazole scaffold SP1 and its nanoformulation with in vivo evaluation of anticancer and antimetastatic activity as potential drug for breast adenocarcinoma. The synthesized compound SP1 exhibited potent growth inhibitory efficacy against four types of human cancer (breast, prostate, colon and lung) cell lines with IC₅₀ = 2.4, 3.4, 7.24 and 7.81 µM and selectivity index 5.79, 4.08, 1.93 and 1.78 respectively. Flow cytometric analysis illustrated that SP1 exhibited high apoptotic effect on all tested cancer cell lines (38.22-52.3 %). The mode of action of this promising compound was declared by its ability to upregulate the gene expression of p21 (2.29-3.91 folds) with suppressing cyclin D (1.9-8.93 folds) and NF-κB (1.26-1.44 fold) in the treated cancer cells. Also, it enhanced the protein expression of apoptotic marker p53 and moderate binding affinity for MDM2 (K_D;7.94 μM). Notwithstanding these promising impressive findings, its selectivity against cancer cell lines and safety on normal cells were improved by nanoformulation. Therefore, SP1 was formulated as ultra-flexible niosomal nanovesicles (transethoniosomes). The ultra-deformability is attributable to the synergism between ethanol and edge activators in improving the flexibility of the nanovesicular membrane. F8 exhibited high deformability index (DI) of (23.48 ± 1.4). It was found that % SP1 released from the optimized transethoniosomal formula (F8) after 12 h (Q_12h) was 84.17 ± 1.29 % and its entrapment efficiency (%EE) was 76.48 ± 1.44 %. Based upon the very encouraging and promising in vitro results, an in vivo study was carried out in female Balb/c mice weighing (15-25 g). SP1 did halt the proliferation of breast cancer cells as well as suppressed the metastasis in other organs like liver, lung and heart.

Electrosynthesis of 2-Substituted Benzoxazoles via Intramolecular Shono-Type Oxidative Coupling of Glycine Derivatives

Herein, an atom-economical and eco-friendly electrochemical oxidation/cyclization of glycine derivatives through intramolecular Shono-type oxidative coupling is disclosed, leading to a variety of 2-substituted benzoxazoles in 51-85% yields. This oxidative cyclization proceeded in transition metal- and oxidant-free conditions and generated H₂ as only a byproduct. Additionally, gram-scale reactions and a broad substrate scope demonstrated the synthetic usefulness of this protocol.

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.

Chalcones as Promising Antitumor Agents by Targeting the p53 Pathway: An Overview and New Insights in Drug-Likeness

The p53 protein is one of the most important tumor suppressors that are frequently inactivated in cancer cells. This inactivation occurs either because the TP53 gene is mutated or deleted, or due to the p53 protein inhibition by endogenous negative regulators, particularly murine double minute (MDM)2. Therefore, the reestablishment of p53 activity has received great attention concerning the discovery of new cancer therapeutics. Chalcones are naturally occurring compounds widely described as potential antitumor agents through several mechanisms, including those involving the p53 pathway. The inhibitory effect of these compounds in the interaction between p53 and MDM2 has also been recognized, with this effect associated with binding to a subsite of the p53 binding cleft of MDM2. In this work, a literature review of natural and synthetic chalcones and their analogues potentially interfering with p53 pathway is presented. Moreover, in silico studies of drug-likeness of chalcones recognized as p53-MDM2 interaction inhibitors were accomplished considering molecular descriptors, biophysiochemical properties, and pharmacokinetic parameters in comparison with those from p53-MDM2 in clinical trials. With this review, we expect to guide the design of new and more effective chalcones targeting the p53 pathway.

Synthesis of benzimidazole based hydrazones as non-sugar based α-glucosidase inhibitors: Structure activity relation and molecular docking

In search for α-glucosidase inhibitors used in the treatment of diabetes mellitus, a series of unique benzimidazole based hydrazones derivatives were synthesized (5a-5p), which were then investigated for their in vitro α-glucosidase inhibitory potential. The compounds of interest were characterized by modern spectroscopic approaches including CHN, ¹ HNM R, ¹³ CN MR and FTIR. The structure of compound 5n was distinctively authenticated through single crystal X-ray study. All compounds depicted potent enzyme inhibitory potential with IC₅₀ values in the range of 2.25 ± 0.01 to 81.16 ± 0.12 μM except 5n that showed IC₅₀ value of 182.75 ± 0.13 μM. A limited structure-activity correlation demonstrated that substitutions of isatin, aldehydes and ketone in hydrazones moiety had remarkable contribution in the overall activity and that was further supported by molecular docking studies carried out in elucidating the mechanism of binding interaction of these compounds in the catalytic site of α-glucosidase.

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.

Nitrogen-Containing Heterocycles as Anticancer Agents: An Overview

Background:

Cancer is spreading all over the world, and it is becoming the leading cause of major deaths. Today’s most difficult task for every researcher is to invent a new drug that can treat cancer with minimal side effects. Many factors, including pollution, modern lifestyle and food habits, exposure to oncogenic agents or radiations, enhanced industrialization, etc. can cause cancer. Treatment of cancer is done by various methods that include chemotherapy, radiotherapy, surgery and immunotherapy in combination or singly along with kinase inhibitors. Most of the anti-cancer drugs use the concept of kinase inhibition.

Objective:

The number of drugs being used in chemotherapy has heterocycles as their basic structure in spite of various side effects. Medicinal chemists are focusing on nitrogen-containing heterocyclic compounds like pyrrole, pyrrolidine, pyridine, imidazole, pyrimidines, pyrazole, indole, quinoline, oxadiazole, azole, benzimidazole, etc. as the key building blocks to develop active biological compounds. The aim of this study is to attempt to compile a dataset of nitrogen-containing heterocyclic anti-cancer drugs.

Methods:

We adopted a structural search on notorious journal publication websites and electronic databases such as Bentham Science, Science Direct, PubMed, Scopus, USFDA, etc. for the collection of peer-reviewed research and review articles for the present review. The quality papers were retrieved, studied, categorized into different sections, analyzed and used for article writing.

Conclusion:

As per FDA databases, nitrogen-based heterocycles in the drug design are almost 60% of unique small-molecule drugs. Some of the nitrogen-containing heterocyclic anti-cancer drugs are Axitinib, Bosutinib, Cediranib, Dasatanib (Sprycel®), Erlotinib (Tarceva®), Gefitinib (Iressa®), Imatinib (Gleevec®), Lapatinib (Tykerb ®), Linifanib, Sorafenib (Nexavar®), Sunitinib (Sutent®), Tivozanib, etc. In the present review, we shall focus on the overview of nitrogen-containing heterocyclic active compounds as anti-cancer agents.

p53: An Attractive Therapeutic Target for Cancer

Cancer is a leading cause of death worldwide. It initiates when cell cycle regulatory genes lose their function either by environmental and/or by internal factors. Tumor suppressor protein p53, known as "Guardian of genome", plays a central role in maintaining genomic stability of the cell. Mutation of TP53 is documented in more than 50% of human cancers, usually by overexpression of negative regulator protein MDM2. Hence, reactivation of p53 by blocking the protein-protein interaction between the murine double minute 2 (MDM2) and the tumor suppressor protein p53 has become the most promising therapeutic strategy in oncology. Several classes of small molecules have been identified as potent, selective and efficient p53-MDM2 inhibitors. Herein, we review the druggability of p53-MDM2 inhibitors and their optimization approaches as well as clinical candidates categorized by scaffold type.

Design, Synthesis, and Biological Evaluation of Aromatic Amide-Substituted Benzimidazole-Derived Chalcones. The Effect of Upregulating TP53 Protein Expression

A series of benzimidazole-derived chalcones containing aromatic amide substituent were designed and synthesized. All of the chalcone compounds were tested for their in vitro antitumor activity against human cancer cell lines (HCT116, HepG2, A549, and CRL-5908). The antiproliferative activity of compounds 3, 6, 9, 14, 15, 16 against HCT116 cells was significantly better than that that of 5-Fluorouracil (IC50: 94.63 µM). The antitumor activity of these compounds showed obvious differences between the wild type HCT116 and mutant HCT116 (TP53^−/−) cells. A preliminary mechanistic study suggested that these compounds act by upregulating the expression of TP53 protein in tumor cells without inhibiting the MDM2-TP53 interaction.

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.

Mutagenic Study of Benzimidazole Derivatives with (+S9) and without (-S9) Metabolic Activation

Benzimidazole derivatives have a diverse range of biological activities, including antiulcer, antihypertensive, antiviral, antifungal, anti-inflammatory, and anticancer. Despite these activities, previous studies have revealed that some of the derivatives can induce mutations. This study aimed to screen for potential mutagenic activities of novel benzimidazole derivatives 1–4 using the Ames test and to study their structure–activity relationship (SAR). An Ames test was carried out on two strains of Salmonella typhimurium (TA98 and TA100) in the absence and presence of metabolic activation. Genetic analysis was performed prior to the Ames test to determine the genotypes of the bacterial tester strains. Both bacterial strains showed dependency on histidine with the presence of rfa mutation, uvrB deletion, and plasmid pKM101. Further, all derivatives tested showed no mutagenic activity in the absence of metabolic activation in both tester strains. However, in the presence of metabolic activation, compound 1 appeared to induce mutation at 2.5 µg/plate when tested against the TA98 strain. These results suggest that the absence of the -OH group at the ortho-position over the phenyl ring might be the cause of increased mutagenic activity in compound 1. Additionally, the presence of mutagenic activity in compound 1 when it was metabolically activated indicates that this compound is a promutagen.

S8-Catalyzed triple cleavage of bromodifluoro compounds for the assembly of N-containing heterocycles

An unprecedented S₈-catalyzed selective triple-cleavage of bromodifluoroacetamides is disclosed for the first time.

An unprecedented S₈-catalyzed selective triple-cleavage of bromodifluoroacetamides is disclosed for the first time. Valuable 2-amido substituted benzimidazoles, benzoxazoles and benzothiazoles were obtained in good to excellent yields in a cascade protocol in this strategy. Mechanistic studies suggested that a C2 source was generated in situ by selective cleavage of three C–X bonds, including two inert C(sp³)–F bonds on bromodifluoroacetamides, while leaving C–C bonds intact. This strategy will undoubtedly further consummate the role of halo difluoro compounds and enrich both fluorine chemistry and pharmaceutical sciences.

Novel cathepsin K inhibitors block osteoclasts in vitro and increase spinal bone density in zebrafish

Cathepsin K (Cat K) is a predominant cysteine protease and highly potent collagenase expressed in osteoclasts. Cat K inhibitors are anti-resorptive agents to treat osteoporosis. A novel scaffold of cathepsin K inhibitors, exemplified by lead compound 1x, was used as the template for designing and synthesizing a total of 61 derivatives that have not been reported before. An exploratory structure–activity relationship analysis identified the potent Cat K inhibitor A22, which displayed an IC₅₀ value of 0.44 μM against Cat K. A22 was very specific for Cat K and caused a significantly higher in vitro inhibition of the enzyme as compared to that of lead compound 1x. A surface plasmon resonance analysis confirmed in vitro binding of A22 to Cat K. Molecular docking studies indicated several favourable interaction sites for A22 within the active pocket of Cat K. Furthermore, A22 also blocked active osteoclasts in vitro and increased spinal bone density in zebrafish, in which it showed an activity that was higher than that of the marketed therapeutic bone metabolizer etidronate disodium. A22 represents a very promising lead compound for the development of novel antiresorptive agents functioning as orthosteric inhibitors of Cat K.

Cathepsin K (Cat K) is a predominant cysteine protease and highly potent collagenase expressed in osteoclasts.

Design, synthesis, and in vitro biological evaluation of novel benzimidazole tethered allylidenehydrazinylmethylthiazole derivatives as potent inhibitors of Mycobacterium tuberculosis

Tuberculosis (TB) has become one of the most significant public health problems in recent years. Antibiotic therapy remains the mainstay of TB control strategies, but the increasing resistance of mycobacterial species has heightened alarm, requiring the development of novel drugs in order to improve treatment outcomes. Here, as an effort to identify novel and effective antitubercular agents, we designed and synthesized a series of novel substituted benzimidazolallylidenehydrazinylmethylthiazole derivatives via a multi-component molecular hybridization approach with single molecular architecture. Our design strategy involved assembling the antitubercular pharmacophoric fragments benzimidazole, 2-aminothiazole and substituted α,β-unsaturated ketones via condensation reactions. All the newly synthesized compounds were fully characterized via NMR and mass spectral data and evaluated for in vitro biological activity against the H37Ra strain of Mycobacterium tuberculosis. From the biological evaluation data, we identified some effective compounds, of which 8g and 7e were the most active ones (both having MIC values of 2.5 μg mL-1). In addition, compound 8g exhibited a lower cytotoxicity profile. We conceive that compound 8g may serve as a chemical probe of interest for further lead optimization studies with the general aim of developing novel and effective antitubercular agents.

Synthesis and evaluation of new benzimidazole derivatives with hydrazone moiety as anticancer agents

Objectives:

Cancer is one of the leading causes of death throughout the world. Current therapy options suffer from the major limitations of side effects and drug resistance. Thus, continuing search for newer and safer anticancer drugs remains critically important. From this point of view, in the present study benzimidazole-hydrazone derivatives were synthesized by aiming at the identification of new chemical entities as potent anticancer agents.

Material and methods:

A series of 12 new compounds of 4-(5(6)-substituted-1H-benzimidazol-2-yl)-N′thiophen/furan-2-yl-methylene) benzohydrazide derivatives were synthesized. The structures of the obtained compounds were elucidated using by IR, 1H NMR, 13C NMR, mass spectroscopy and elemental analyses. In vitro cytotoxic activity of the compounds against A549, MCF-7 and NIH/3T3 cell lines was evaluated by MTT assay.

Results:

Among the tested compounds, compound 3e showed higher cytotoxicity against MCF-7 human breast cancer cells when compared with cisplatin. Also, it has lower cytotoxicty against healthy cell line, NIH/3T3.

Conclusions:

It was determined that compound 3e showed inhibition towards MCF-7. Considering the substituent effect on cytotoxic activity, compound 3e bearing 2-methylthiophene has attracted attention with its higher anticancer activities.

Discovery of Benzimidazole-Quinolone Hybrids as New Cleaving Agents toward Drug-Resistant Pseudomonas aeruginosa DNA

A series of benzimidazole-quinolone hybrids as new potential antimicrobial agents were designed and synthesized. Bioactive assays indicated that some of the prepared compounds exhibited potent antibacterial and antifungal activities. Notably, 2-fluorobenzyl derivative 5 b (ethyl 7-chloro-6-fluoro-1-[[1-[(2-fluorophenyl)methyl]benzimidazol-2-yl]methyl]-4-oxo-quinoline-3-carboxylate) showed remarkable antimicrobial activity against resistant Pseudomonas aeruginosa and Candida tropicalis isolated from infected patients. Active molecule 5 b could not only rapidly kill the tested strains, but also exhibit low toxicity toward Hep-2 cells. It was more difficult to trigger the development of bacterial resistance of P. aeruginosa against 5 b than that against norfloxacin. Molecular docking demonstrated that 5 b could effectively bind with topoisomerase IV-DNA complexes, and quantum chemical studies theoretically elucidated the good antimicrobial activity of compound 5 b. Preliminary experimental reaction mechanism exploration suggested that derivative 5 b could not intercalate into DNA isolated from drug-resistant P. aeruginosa, but was able to cleave DNA effectively, which might further block DNA replication to exert powerful bioactivities. In addition, compound 5 b is a promising antibacterial agent with membrane disruption abilities.

Synthesis and biological evaluation of novel synthetic chalcone derivatives as anti-tumor agents targeting Cat L and Cat K

A series of chalcone derivatives bearing benzamide or benzenesulfonamide moieties were synthesized and evaluated for their anti-tumor effect on HCT116, MCF7 and 143B cell lines in vitro. SAR analysis showed that compounds bearing a benzenesulfonamide group had greater potency than those bearing a benzamide group. It was also shown that compounds with a mono-methyl or mono-halogen group at the 3-position on the terminal phenyl ring were more effective than those with trifluoromethyl or methoxy groups. Compound 8e exhibited the most potent anti-tumor activities against HCT116, MCF7 and 143B cell lines, with IC₅₀ values of 0.597, 0.886 and 0.791μM, respectively. Molecular docking studies and enzymatic assays demonstrated that the anti-tumor activity of compound 8e might be regulated by Cat L and Cat K.

Benzimidazole Scaffold as Anticancer Agent: Synthetic Approaches and Structure-Activity Relationship

Cancer, also known as malignant neoplasm, is a dreadful disease which involves abnormal cell growth having the potential to invade or spread to other parts of the body. Benzimidazole is an organic compound that is heterocyclic and aromatic in nature. It is a bicyclic compound formed by the fusion of the benzene and imidazole ring systems. It is an important pharmacophore and a privileged structure in medicinal chemistry. According to the World Health Organisation (2015 survey), one in six deaths is due to cancer around the globe, accounting for 8.8 million deaths of which 70% of the cases were from low- and middle-income countries. In the efforts to develop suitable anticancer drugs, medicinal chemists have focussed on benzimidazole derivatives. This review article covers the current development of benzimidazole-based anticancer agents along with the synthetic approaches and structure-activity relationships (SAR).

Synthesis and in vitro cytotoxic evaluation of new 1H-benzo[d]imidazole derivatives of dehydroabietic acid

A series of new 1H-benzo[d]imidazole derivatives of dehydroabietic acid were designed and synthesized as potent antitumor agents. Structures of the target molecules were characterized using MS, IR, ¹H NMR, ¹³C NMR and elemental analyses. In the in vitro cytotoxic assay, most compounds showed significant cytotoxic activities against two hepatocarcinoma cells (SMMC-7721 and HepG2) and reduced cytotoxicity against noncancerous human hepatocyte (LO2). Among them, compound 7b exhibited the best cytotoxicity against SMMC-7721 cells (IC₅₀: 0.36±0.13μM), while 7e was most potent to HepG2 cells (IC₅₀: 0.12±0.03μM). The cell cycle analysis indicated that compound 7b caused cell cycle arrest of SMMC-7721 cells at G2/M phase. Further, compound 7b also induced the apoptosis of SMMC-7721 cells in Annexin V-APC/7-AAD binding assay.

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.

Microwave-assisted rapid synthesis of sugar-based pyrazole derivatives with anticancer activity in water

A rapid, efficient and green method has been developed for the synthesis of some novel sugar-based pyrazole derivatives in eco-friendly water under microwave irradiation in good yields.