Synthesis of ferrocenyl pyrazole-containing chiral aminoethanol derivatives and their inhibition against A549 and H322 lung cancer cells

Ferrocenyl Azoles: Versatile N-Containing Heterocycles and their Anticancer Activities

The medicinal chemistry of ferrocene has gained its momentum after the discovery of biological activities of ferrocifen and ferroquine. These ferrocenyl drugs have been designed by replacing the aromatic moiety of the organic drugs, tamoxifen and chloroquine respectively, with a ferrocenyl unit. The promising biological activities of these ferrocenyl drugs have paved a path to explore the medicinal applications of several ferrocenyl conjugates. In these conjugates, the ferrocenyl moiety has played a vital role in enhancing or imparting the anticancer activity to the molecule. The ferrocenyl conjugates induce the cytotoxicity by generating reactive oxygen species and thereby damaging the DNA. In medicinal chemistry, the five membered nitrogen heterocycles (azoles) play a significant role due to their rigid ring structure and hydrogen bonding ability with the biomolecules. Several potent drug candidates with azole groups have been in use as chemotherapeutics. Considering the importance of ferrocenyl moiety and azole groups, several ferrocenyl azole conjugates have been synthesized and screened for their biological activities. Hence, in the view of a wide scope in the development of potent drugs based on ferrocenyl azole conjugates, herein we present the details of synthesis and the anticancer activities of ferrocenyl compounds bearing azole groups such as imidazole, triazoles, thiazole and isoxazoles.

Recent Advancement in Drug Design and Discovery of Pyrazole Biomolecules as Cancer and Inflammation Therapeutics

Pyrazole, an important pharmacophore and a privileged scaffold of immense significance, is a five-membered heterocyclic moiety with an extensive therapeutic profile, viz., anti-inflammatory, anti-microbial, anti-anxiety, anticancer, analgesic, antipyretic, etc. Due to the expansion of pyrazolecent red pharmacological molecules at a quicker pace, there is an urgent need to put emphasis on recent literature with hitherto available information to recognize the status of this scaffold for pharmaceutical research. The reported potential pyrazole-containing compounds are highlighted in the manuscript for the treatment of cancer and inflammation, and the results are mentioned in % inhibition of inflammation, % growth inhibition, IC50, etc. Pyrazole is an important heterocyclic moiety with a strong pharmacological profile, which may act as an important pharmacophore for the drug discovery process. In the struggle to cultivate suitable anti-inflammatory and anticancer agents, chemists have now focused on pyrazole biomolecules. This review conceals the recent expansion of pyrazole biomolecules as anti-inflammatory and anticancer agents with an aim to provide better correlation among different research going around the world.

Convenient Synthesis of N-Heterocycle-Fused Tetrahydro-1,4-diazepinones

A general approach towards the synthesis of tetrahydro-4H-pyrazolo[1,5-a][1,4]diazepin-4-one, tetrahydro[1,4]diazepino[1,2-a]indol-1-one and tetrahydro-1H-benzo[4,5]imidazo[1,2-a][1,4]diazepin-1-one derivatives was introduced. A regioselective strategy was developed for synthesizing ethyl 1-(oxiran-2-ylmethyl)-1H-pyrazole-5-carboxylates from easily accessible 3(5)-aryl- or methyl-1H-pyrazole-5(3)-carboxylates. Obtained intermediates were further treated with amines resulting in oxirane ring-opening and direct cyclisation-yielding target pyrazolo[1,5-a][1,4]diazepin-4-ones. A straightforward two-step synthetic approach was applied to expand the current study and successfully functionalize ethyl 1H-indole- and ethyl 1H-benzo[d]imidazole-2-carboxylates. The structures of fused heterocyclic compounds were confirmed by ¹H, ¹³C, and ¹⁵N-NMR spectroscopy and HRMS investigation.

Synthesis of New 1-Aryl-2-(3,5-dimethylpyrazol-1-yl)ethanone Oxime Ether Derivatives and Investigation of Their Cytotoxic Effects

In this study, 12 new 1-aryl-2-(3,5-dimethylpyrazol-1-yl)ethanone oxime ether derivatives were designed and synthesized to investigate their cytotoxic effects. The in vitro cytotoxic activities of the compounds were evaluated against cervix, colon, breast, glioma, neuroblastoma, and lung cancer cell lines, as well as a healthy cell line using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazo-lium bromide (MTT) assays with 5-fluorouracil (5-FU) as the reference compound. Compound 5f (IC50 = 5.13 µM) was found to be more effective than 5-FU (IC50 = 8.34 µM) in the C6 cancer cell line, and it had no cytotoxic effect on the L929 healthy cell line. Flow cytometry was used to investigate the mechanism of action of compound 5f on the cell cycle of the C6 cell line. The analysis showed that cell death was significantly due to apoptosis. These results indicate that compound 5f induces cell cycle arrest, and may be effective in treating glioma.

Methyl linked pyrazoles: Synthetic and Medicinal Perspective

Pyrazoles, an important and well known class of the azole family, have been found to show a large number of applications in various fields specially of medicinal chemistry. Among pyrazole derivatives, particularly, methyl substituted pyrazoles have been reported as the potent medicinal scaffolds that exhibit a wide spectrum of biological activities. The present review is an attempt to highlight the detailed synthetic approaches for methyl substituted pyrazoles along with in depth analysis of their respective medical significances till March2021. It is hoped that literature sum-up in the form of present review article would certainly be a great tool to assist the medicinal chemists for generating new leads possessing pyrazole nucleus with high efficacy and less microbial resistance.

Recent Progress on Anticancer Agents Incorporating Pyrazole Scaffold

The search of new anticancer agents is considered as a dynamic field of medicinal chemistry. In recent years, the synthesis of compounds with anticancer potential has increased and a large number of structurally varied compounds displaying potent anticancer activities have been published. Pyrazole is an important biologically active scaffold that possessed nearly all types of biological activities. The aim of this review is to collate literature work reported by researchers to provide an overview on in vivo and in vitro anticancer activities of pyrazole based derivatives among the diverse biological activities displayed by them and also presents recent efforts made on this heterocyclic moiety regarding anticancer activities. This review has been driven from the increasing number of publications, on this issue, which have been reported in the literature since the ending of the 20th century (from 1995-to date).

Pyrazoline Hybrids as Promising Anticancer Agents: An Up-to-Date Overview

Pyrazolines are five-membered heterocycles possessing two adjacent nitrogens. They have attracted significant attention from organic and medicinal chemists due to their potent biological activities and the numerous possibilities for structural diversification. In the last decade, they have been intensively studied as targets for potential anticancer therapeutics, producing a steady yearly rise in the number of published research articles. Many pyrazoline derivatives have shown remarkable cytotoxic activities in the form of heterocyclic or non-heterocyclic based hybrids, such as with coumarins, triazoles, and steroids. The enormous amount of related literature in the last 5 years prompted us to collect all these published data from screening against cancer cell lines, or protein targets like EGFR and structure activity relationship studies. Therefore, in the present review, a comprehensive account of the compounds containing the pyrazoline nucleus will be provided. The chemical groups and the structural modifications responsible for the activity will be highlighted. Moreover, emphasis will be given on recent examples from the literature and on the work of research groups that have played a key role in the development of this field.

Ferrocene-containing hybrids as potential anticancer agents: Current developments, mechanisms of action and structure-activity relationships

Cancer is one of the most fatal threatens to human health throughout the world. The major challenges in the control and eradication of cancers are the continuous emergency of drug-resistant cancer and the low specificity of anticancer agents, creating an urgent need to develop novel anticancer agents. Organometallic compounds especially ferrocene derivatives possess remarkable structural and mechanistic diversity, inherent stability towards air, heat and light, low toxicity, low cost, reversible redox, ligand exchange, and catalytic properties, making them promising drug candidates for cancer therapy. Ferrocifen, a ferrocene-phenol hybrid, has demonstrated promising anticancer properties on drug-resistant cancers. Currently, Ferrocifen is in pre-clinical trial against cancers. Obviously, ferrocene moiety is a useful template for the development of novel anticancer agents. This review will provide an overview of ferrocene-containing hybrids with potential application in the treatment of cancers covering articles published between 2010 and 2020. The mechanisms of action, the critical aspects of design and structure-activity relationships are also discussed.

Synthesis and Pharmacological Activities of Pyrazole Derivatives: A Review

Pyrazole and its derivatives are considered a pharmacologically important active scaffold that possesses almost all types of pharmacological activities. The presence of this nucleus in pharmacological agents of diverse therapeutic categories such as celecoxib, a potent anti-inflammatory, the antipsychotic CDPPB, the anti-obesity drug rimonabant, difenamizole, an analgesic, betazole, a H2-receptor agonist and the antidepressant agent fezolamide have proved the pharmacological potential of the pyrazole moiety. Owing to this diversity in the biological field, this nucleus has attracted the attention of many researchers to study its skeleton chemically and biologically. This review highlights the different synthesis methods and the pharmacological properties of pyrazole derivatives. Studies on the synthesis and biological activity of pyrazole derivatives developed by many scientists around the globe are reported.

Synthesis and Pharmacological Activities of Pyrazole Derivatives: A Review

Pyrazole and its derivatives are considered a pharmacologically important active scaffold that possesses almost all types of pharmacological activities. The presence of this nucleus in pharmacological agents of diverse therapeutic categories such as celecoxib, a potent anti-inflammatory, the antipsychotic CDPPB, the anti-obesity drug rimonabant, difenamizole, an analgesic, betazole, a H2-receptor agonist and the antidepressant agent fezolamide have proved the pharmacological potential of the pyrazole moiety. Owing to this diversity in the biological field, this nucleus has attracted the attention of many researchers to study its skeleton chemically and biologically. This review highlights the different synthesis methods and the pharmacological properties of pyrazole derivatives. Studies on the synthesis and biological activity of pyrazole derivatives developed by many scientists around the globe are reported.

Microwave-Assisted Syntheses of Bioactive Seven-Membered, Macro-Sized Heterocycles and Their Fused Derivatives

This review describes the recent advances in the microwave-assisted synthesis of 7-membered and larger heterocyclic compounds. Several types of reaction for the cyclization step are discussed: Ring Closing Metathesis (RCM), Heck and Sonogashira reactions, Suzuki-Miyaura cross-coupling, dipolar cycloadditions, multi-component reactions (Ugi, Passerini), etc. Green syntheses and solvent-free procedures have been introduced whenever possible. The syntheses discussed herein have been selected to illustrate the huge potential of microwave in the synthesis of highly functionalized molecules with potential therapeutic applications, in high yields, enhanced reaction rates and increased chemoselectivity, compared to conventional methods. More than 100 references from the recent literature are listed in this review.

Biological Evaluation of Ferrocenyl Olefins: Cancer Cell Growth Inhibition, ROS Production, and Apoptosis Activity

The antiproliferative effects of various ferrocenyl olefins were evaluated against the cell lines MCF-7 (human breast cancer cells), DLD-1 (human colon adenocarcinoma cells), HUVEC (human umbilical vein endothelial cells), and A549 (human lung carcinoma cells), using the MTT test. IC50 values were determined. Compounds 8, 9, 11, and 12 with high antiproliferative activity were tested for their reactive oxygen species (ROS) production, and cell cycle analysis was performed on A549 cells. The results show that these compounds might perform their antiproliferative activity through inducing ROS generation, apoptosis induction, and cell cycle arrest.

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.

Evaluation of the protective potential of brain microvascular endothelial cell autophagy on blood-brain barrier integrity during experimental cerebral ischemia-reperfusion injury

Brain microvascular endothelial cell (BMVEC) injury induced by ischemia-reperfusion (I/R) is the initial phase of blood-brain barrier (BBB) disruption, which results in a poor prognosis for ischemic stroke patients. Autophagy occurs in ischemic brain and has been shown to exhibit protective effects on endothelial cell against stress. However, the potential effects of BMVEC autophagy on BBB permeability during I/R and the mechanisms underlying these effects have yet to be elucidated. In the current study, we answered these questions by using chemical modulators of autophagy, including rapamycin and lithium carbonate acting, respectively, as mammalian target of rapamycin (mTOR)-dependent and mTOR-independent autophagy inducers and 3-methyladenine (3-MA) as an autophagy inhibitor. To mimic I/R injury, BMVECs were exposed to oxygen-glucose deprivation/reoxygenation (OGD/R), and a rat transient middle cerebral artery occlusion/reperfusion (MCAO/R) model was performed. All the drugs were given at 0.5 h before OGD/R or MCAO/R. First, enhancement of autophagy by rapamycin and lithium carbonate attenuated, whereas suppression of autophagy by 3-MA intensified BMVEC apoptosis and the high level of ROS induced by OGD/R. In addition, rapamycin and lithium carbonate pretreatments significantly reversed the decreased level of tight junction protein zonula occludens-1 (ZO-1) induced by OGD/R and promoted the distribution of ZO-1 on cell membranes. Finally, pretreatments with rapamycin and lithium carbonate reduced evans blue extravasation and brain water content in the ischemic hemisphere of the rat. In contrast, 3-MA pretreatment exerted opposite effects both in vitro and in vivo. These results may indicate a beneficial effect of BMVEC autophagy on BBB integrity during I/R injury.

The synthesis, characterization and optical properties of novel 5-(3-aryl-1H-pyrazol-5-yl)-2-(3-butyl-1-chloroimidazo[1,5-a]pyridin-7-yl)-1,3,4-oxadiazole

A series of novel 5-(3-aryl-1H-pyrazol-5-yl)-2-(3-butyl-1-chloroimidazo[1,5-a]- pyridin-7-yl)-1,3,4-oxadiazole derivatives has been synthesized from 3-butyl-1-chloroimidazo[1,5-a]pyridine-7-carboxylic acid and ethyl 3-aryl-1H-pyrazole-5-carboxylate. The compounds were characterized using IR, (1)H NMR, HRMS and UV-vis absorption. The fluorescence spectral characteristics of the compounds in dichloromethane were investigated. The results showed that absorption λmax and emission λmax was less correlated with substituent groups on N-1 position of pyrazole moiety and para position of benzene moiety. The calculated molecular orbital correlates well with their absorption.

Synthesis and X-ray Structure Characterisation of Novel Pyrazole Carboxamide Derivatives

A series of novel pyrazole carboxamide derivatives containing piperazine moiety was synthesised and determined by IR, 1H NMR and HRMS spectroscopy. Especially, the structure was confirmed by the X-ray crystal analysis of [1-(4- tert-butylbenzyl)-4-chloro-3-(4-chlorophenyl)-1 H-pyrazol-5-yl](4-phenylpiperazin-1-yl)methanone.