Recent Progress of Benzimidazole Hybrids for Anticancer Potential.

This review presents the detailed account of factors leading to cancer and design strategy for the synthesis of benzimidazole derivatives as anticancer agents. The recent survey for cancer treatment in Cancer facts and figures 2017 American Chemical Society has shown progressive development in fighting cancer. Researchers all over the world in both developed and developing countries are in a continuous effort to tackle this serious concern. Benzimidazole and its derivatives showed a broad range of biological activities due to their resemblance with naturally occurring nitrogenous base i.e. purine. The review discussed benzimidazole derivatives showing anticancer properties through a different mechanism viz. intercalation, alkylating agents, topoisomerases, DHFR enzymes, and tubulin inhibitors. Benzimidazole derivatives act through a different mechanism and the substituents reported from the earlier and recent research articles are prerequisites for the synthesis of targeted based benzimidazole derivatives as anticancer agents. The review focuses on an easy comparison of the substituent essential for potency and selectivity through SAR presented in figures. This will further provide a better outlook or fulfills the challenges faced in the development of novel benzimidazole derivatives as anticancer.

Novel 9-(2-(1-arylethylidene)hydrazinyl)acridine derivatives: Target Topoisomerase 1 and growth inhibition of HeLa cancer cells.

A series of 9-(2-(1-arylethylidene)hydrazinyl)acridine and its analogs were designed, synthesized and evaluated for biological activities. Various biochemical assays were performed to determine the free radical scavenging capacity of synthesized compounds (4a-4j). Anticancer activity of these compounds was assessed against two different human cancer cell lines viz cervical cancer cells (HeLa) and liver cancer cells (HepG2) as well as normal human embryonic kidney cell line (HEK 293). Compounds 4b, 4d and 4e showed potential anti-proliferative effects on HeLa cells. Based on results obtained from antioxidant and cytotoxicity studies, 4b, 4d and 4e were further studied in detail for different biological activities. 4b, 4d and 4e reduced the cell growth, inhibited metastatic activity and declined the potential of cell migration in HeLa cell lines. Topoisomerase1 (Top1) treated with compounds 4b, 4d and 4e exhibited inhibition of Top1 and prevented DNA replication. Molecular docking results validate that interaction of compounds 4b, 4d and 4e with Top1-DNA complex, which might be accountable for their inhibitory effects. Further it was concluded that compounds 4b, 4d and 4e arrests the cells at S phase and consequently induces cell death through DNA damage in HeLa cells.

Synthesis of stable benzimidazole derivatives bearing pyrazole as anticancer and EGFR receptor inhibitors.

A new series of benzimidazole linked pyrazole derivatives were synthesized by cyclocondensation reaction through one-pot multicomponent reaction in absolute ethanol. All the synthesized compounds were tested for their in vitro anticancer activities on five human cancer cell lines including MCF-7, HaCaT, MDA-MB231, A549 and HepG2. EGFR receptor inhibitory activities were carried out for all the compounds. Majority of the compounds showed potent antiproliferative activity against the tested cancer cell lines. Compound 5a showed the most effective activity against the lungs cancer cell lines (IC50 = 2.2 µM) and EGFR binding (IC50 = 0.97 µM) affinity as compared to other members of the series. Compound 5a inhibited growth of A549 cancer cells by inducing a strong G2/M phase arrest. In addition, same compound inhibited growth of A549 cancer cells by inducing apoptosis. In molecular docking studies compound 5a was bound to the active pocket of the EGFR (PDB 1M17) with five key hydrogen bonds and two π-π interaction with binding energies ΔG = -34.581 Kcal/mol.

Design and synthesis of quinazoline-3,4-(4H)-diamine endowed with thiazoline moiety as new class for DPP-4 and DPPH inhibitor.

New N3-benzylidene (substituted)-2-phenyl-N4-(thiazol-2-yl)-quinazoline-3,4-(4H)-diamine derivatives were design and synthesized by a sequence of reactions starting from appropriate 6-methyl anthranilic acid. The title compounds were screened for in vitro dipeptidyl peptidase IV (DPP-4) inhibitory activity and diphenyl-2-picryl-hydrazyl (DPPH) assay and results showed significant to good activity in compared to Linagliptin for antidiabetic activity and Ascorbic acid for antioxidant activity. Compound 7g (IC50=0.76nM) exhibited most promising DPP-4 inhibitory activity and also showed good antioxid and result. Docking study was also performed to provide an insight about the binding mode into binding sites of DPP-4 enzyme. Hopefully in future, compound 7g could be used as a lead compound for developing new antidiabetic agent with good antioxidant property.

Design, Synthesis, and Biological Evaluation of Novel Quinazoline Clubbed Thiazoline Derivatives.

A novel series of quinazoline clubbed thiazoline derivatives was rationally designed and synthesized. The newly synthesized compounds were evaluated for in vitro dipeptidyl peptidase IV (DPP-4) inhibitory activity. Compounds that showed good to moderate activity were compared using linagliptin as standard. Compound 4x (IC50 = 1.12 nM) exhibited the most promising results. The special chemical feature of compound 4x also imparts good inhibition selectivity for DPP-4 over DPP-8/9. Moreover, docking of compound 4x into the active site of DPP-4 illustrates its possible binding interactions.

Structure-activity relationship (SAR) study and design strategies of nitrogen-containing heterocyclic moieties for their anticancer activities.

The present review article offers a detailed account of the design strategies employed for the synthesis of nitrogen-containing anticancer agents. The results of different studies describe the N-heterocyclic ring system is a core structure in many synthetic compounds exhibiting a broad range of biological activities. Benzimidazole, benzothiazole, indole, acridine, oxadiazole, imidazole, isoxazole, pyrazole, triazoles, quinolines and quinazolines including others drugs containing pyridazine, pyridine and pyrimidines are covered. The following studies of these compounds suggested that these compounds showed their antitumor activities through multiple mechanisms including inhibiting protein kinase (CDK, MK-2, PLK1, kinesin-like protein Eg5 and IKK), topoisomerase I and II, microtubule inhibition, and many others. Our concise representation exploits the design and anticancer potency of these compounds. The direct comparison of anticancer activities with the standard enables a systematic analysis of the structure-activity relationship among the series.

Recent Advances in the Synthesis and Anticancer Activity of Some Molecules Other Than Nitrogen Containing Heterocyclic Moeities.

OBJECTIVE: The present review article presented a detailed account of the design strategies and the structure activity relationship of different derivatives apart from the nitrogen containing ring. These scaffolds play an important part in the drug discovery which showed anticancer activity against different human cancer cell lines through apoptosis, cell cycle arrest, inhibiting kinases, angiogenesis, disruption of cell migration, modulation of nuclear receptor responsiveness and others. Naphthalenes amides/amidines, furan, podophyllotoxin, platinum compounds, steroids, and urea, which forms the core part or along with other N-heterocyclic rings are enclosed. Some of these compounds e.g. podophyllotoxin and platinum based drugs displayed anticancer activity at nanomolar range. Various substitutions from the earlier and latest information are prerequisite in the drug synthesis process. CONCLUSION: The review focused on the recent development of these derivatives, design and anticancer properties, thus providing with the most profound knowledge for the development of targeted based anticancer drugs.

Design, synthesis, docking and QSAR study of substituted benzimidazole linked oxadiazole as cytotoxic agents, EGFR and erbB2 receptor inhibitors.

The synthesis of benzimidazole linked oxadiazole derivatives designed as potential EGFR and erbB2 receptor inhibitors with anticancer and apoptotic activity were studied. Compounds 7a specifically inhibit EGFR and erbB2 receptor at 0.081 and 0.098 µM concentration. Some of the compounds showed strong, broad-spectrum antiproliferative activitiy when tested against five human cancer cell lines. Compounds 7a and 7n were more cytotoxic than 5-fluorouracil against MCF-7 cancer cell, with IC50 values of 5.0 and 2.55 µM whereas, only 7a led to cell cycle arrest at G2/M phase accompanied by an increase in apoptosis. Compounds 7a and 7n showed normal architecture of myofibrils in cardiomyopathy study whereas only compound 7a showed nearly equal biochemical parameters (SGOT and SGPT) when compared to control. Molecular docking & 3D-QSAR studies were used to establish interactions of 7a and 7n within the active site of enzyme for ATP binding site of kinase domain.

Design, Synthesis, and Biological Evaluation of 6-(2-Amino-substituted phenyl)-4-(substituted phenyl)-1,2,4-triazine-3,5(2H,4H)-dione Derivatives as Anticonvulsant Agents.

As per structural requirement essential for anticonvulsant activity, a series of new 6-(2-amino-substituted phenyl)-4-(substituted phenyl)-1,2,4-triazine-3,5-dione derivatives were designed and synthesized. All the synthesized title derivatives were assessed for in vivo anticonvulsant screening by the two most employed standard animal seizure models, maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole (scPTZ)-induced seizures, along with minimal motor impairment screening by rotarod test. Among all the synthesized compounds, the compound 4r showed excellent anticonvulsant activity with neither signs of neurotoxicity in the minimal motor impairment test nor signs of hepatotoxicity in the serum enzyme activity assay. The in silico studies of these title compounds were carried out for estimation of a pharmacophore pattern and the prediction of pharmacokinetic properties. To know the exact mechanism of our title compounds, a molecular docking study was carried out on the homology model of sodium ion (Na(+) ) channel and GABAA receptors. The results of the docking study as well as the in vitro study on both the receptors showed that our target compounds best act through the GABAA receptor rather than the Na(+) channel receptors. Additionally, GABA enzyme estimation was performed for further confirmation of the mechanism involved in its anticonvulsant activity. Conclusively, the compound 4r presents a novel scaffold in the search for safer and efficient anticonvulsants having neuroprotective as well as GABAergic effects.