2-Aryl-3-phenylamino-4,5-dihydro-2h-benz[g]indazoles with analgesic activity

A comprehensive review on phosphatidylinositol-3-kinase (PI3K) and its inhibitors bearing pyrazole or indazole core for cancer therapy

Cancer is a complex and multifaceted group of diseases with a high mortality rate characterized by uncontrolled proliferation of abnormal cells. Dysregulation of normal signalling pathways in cancer contributes to the different hallmarks of this disease. The signalling pathway of which phosphatidylinositol 3-kinase (PI3K) is a part is not an exception. In fact, dysregulated activation of PI3K signalling pathways can result in unbridled cellular proliferation and enhanced cell survival, thereby fostering the onset and advancement of cancer. Therefore, there is substantial interest in developing targeted therapies specifically aimed at inhibiting the PI3K enzyme and its associated pathways. Also, the therapeutic interest on pyrazoles and indazoles has been growing due to their various medicinal properties, namely, anticancer activity. Derivatives of these compounds have been studied as PI3K inhibitors, and they showed promising results. There are already some PI3K inhibitors approved by Food and Drug Administration (FDA), such as Idelalisib (Zydelig®) and Alpelisib (Piqray®). In this context, this review aims to address the importance of PI3K in cellular processes and its role in cancer. Additionally, it aims to report a comprehensive literature review of PI3K inhibitors, containing the pyrazole and indazole scaffolds, published in the last fifteen years, focusing on structure-activity relationship aspects, thus providing important insights for the design of novel and more effective PI3K inhibitors.

A review of poly(ADP-ribose)polymerase-1 (PARP1) role and its inhibitors bearing pyrazole or indazole core for cancer therapy

Cancer is a disease with a high mortality rate characterized by uncontrolled proliferation of abnormal cells. The hallmarks of cancer evidence the acquired cells characteristics that promote the growth of malignant tumours, including genomic instability and mutations, the ability to evade cellular death and the capacity of sustaining proliferative signalization. Poly(ADP-ribose) polymerase-1 (PARP1) is a protein that plays key roles in cellular regulation, namely in DNA damage repair and cell survival. The inhibition of PARP1 promotes cellular death in cells with homologous recombination deficiency, and therefore, the interest in PARP protein has been rising as a target for anticancer therapies. There are already some PARP1 inhibitors approved by Food and Drug Administration (FDA), such as Olaparib and Niraparib. The last compound presents in its structure an indazole core. In fact, pyrazoles and indazoles have been raising interest due to their various medicinal properties, namely, anticancer activity. Derivatives of these compounds have been studied as inhibitors of PARP1 and presented promising results. Therefore, this review aims to address the importance of PARP1 in cell regulation and its role in cancer. Moreover, it intends to report a comprehensive literature review of PARP1 inhibitors, containing the pyrazole and indazole scaffolds, published in the last fifteen years, focusing on structure-activity relationship aspects, thus providing important insights for the design of novel and more effective PARP1 inhibitors.

Molecular and Epigenetic Aspects of Opioid Receptors in Drug Addiction and Pain Management in Sport

Opioids are substances derived from opium (natural opioids). In its raw state, opium is a gummy latex extracted from Papaver somniferum. The use of opioids and their negative health consequences among people who use drugs have been studied. Today, opioids are still the most commonly used and effective analgesic treatments for severe pain, but their use and abuse causes detrimental side effects for health, including addiction, thus impacting the user's quality of life and causing overdose. The mesocorticolimbic dopaminergic circuitry represents the brain circuit mediating both natural rewards and the rewarding aspects of nearly all drugs of abuse, including opioids. Hence, understanding how opioids affect the function of dopaminergic circuitry may be useful for better knowledge of the process and to develop effective therapeutic strategies in addiction. The aim of this review was to summarize the main features of opioids and opioid receptors and focus on the molecular and upcoming epigenetic mechanisms leading to opioid addiction. Since synthetic opioids can be effective for pain management, their ability to induce addiction in athletes, with the risk of incurring doping, is also discussed.

A review on synthetic strategy, molecular pharmacology of indazole derivatives, and their future perspective

With different nitrogen-containing heterocyclic moieties, Indazoles earn one of the places among the top investigated molecules in medicinal research. Indazole, an important fused aromatic heterocyclic system containing benzene and pyrazole ring with a chemical formula of C₇ H₆ N₂ , is also called benzopyrazole. Indazoles consist of three tautomeric forms in which 1H-tautomers (indazoles) and 2H-tautomers (isoindazoles) exist in all phases. The tautomerism in indazoles greatly influences synthesis, reactivity, physical and even the biological properties of indazoles. The thermodynamic internal energy calculation of these tautomers points view 1H-indazole as the predominant and stable form over 2H-indazole. The natural source of indazole is limited and exists in alkaloidal nature (i.e., nigellidine, nigeglanine, nigellicine, etc.) found from Nigella plants. Some of the FDA-approved drugs like Axitinib, Entrectinib, Niraparib, Benzydamine, and Granisetron are being used to treat renal cell cancer, non-small cell lung cancer (NSCLC), epithelial ovarian cancer, chronic inflammation, chemotherapy-induced nausea, vomiting, and many more uses. Besides all these advantages regarding its biological activity, the main issue about indazoles is the less abundance in plant sources, and their synthetic derivatives also often face problems with low yield. In this review article, we discuss its chemistry, tautomerism along with their effects, different schematics for the synthesis of indazole derivatives, and their different biological activities.

Direct Formation of 2-Substituted 2H-Indazoles by a Pd-Catalyzed Reaction between 2-Halobenzyl Halides and Arylhydrazines

A direct and operationally simple method for the regioselective synthesis of 2-aryl-substituted 2H-indazoles is reported. The Pd-catalyzed reaction between easily available 2-bromobenzyl bromides and arylhydrazines employing Cs₂CO₃ as the base and t-Bu₃PHBF₄ as the ligand in DMSO at 120 °C in a sealed tube delivers the 2-substituted-2H-indazoles in a single synthetic step with yields up to 79%. The new method is based on a regioselective intermolecular N-benzylation followed by intramolecular N-arylation and oxidation.

Gold-Catalyzed Bicyclic Annulations of 2-Alkynylbenzaldehydes with Vinyldiazo Carbonyls that Serve as Five-atom Building Units

This work reports gold-catalyzed bicyclic annulations of 2-alkynyl-1-carbonylbenzenes with vinyldiazo ketones that serve as five-atom building units. The importance of these reactions is to access 4,5-dihydro-benzo[g]indazoles, which form the structural cores of various bioactive molecules. According to our mechanistic analysis, we postulate initial [5+4]-cycloadditions between benzopyrilium intermediates and vinyldiazo ketones, followed by 6-π-electrocyclizations to achieve the excellent stereoselectivity.

A new 2H-benzindazole compound from Alternaria alternata Shm-1, an endophytic fungus isolated from the fresh wild fruit of Phellinus igniarius

Endophytic fungi have been shown in recent years to produce a series of bioactive secondary metabolites. Several endophytic fungi were isolated from the fresh wild body of Phellinus igniarius, and initially evaluated for their antimicrobial activity. Among which, Shm-1 extract showed moderate inhibitory activity against Clavibacter michiganense and the fungus was identified to be Alternaria alternata Shm-1 through the comparison of morphological characteristics and the sequence of the rDNA ITS with those of other Alternaria species. A new 2H-benzindazole derivative, alterindazolin A (1), has been isolated from cultures of the endophyte Alternaria alternata Shm-1. Its structure was characterized as 1-benzyl-5-p-hydroxy-phenyloxygen-benz[e]indazole by spectroscopic data analysis including 1D NMR, 2D NMR and MS spectrum.

Synthesis of a new class of pyrazole embedded spirocyclic scaffolds using magnetically separable Fe3O4@SiO2–SO3H nanoparticles as recyclable solid acid support

A green methodology for the synthesis of a new class of pyrazole embedded spirocyclic scaffolds has been developed using Fe₃O₄@SiO₂–SO₃H magnetic nanoparticles.

Synthesis and Evaluation of N-substituted Imidazole Derivatives for Antimicrobial Activity

A series of N-substituted imidazole derivatives was synthesized. Imidazole nucleus was reacted with ethylchloroacetate to form imidazole ester. Reaction of the imidazole ester (I) with different amines yields the desired products (1a- 1e). The compounds were characterized by FT-IR, ¹H-NMR and mass spectra. The synthesized compounds were evaluated for the antimicrobial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Aspergillus niger by determination of MIC (minimum inhibitory concentration) using tube dilution method. Compound (1b) was found to be the most active antimicrobial compound amongst others in the series.

Synthesis of new 5,6-dihydrobenzo[h]quinazoline 2,4-diamino substituted and antiplatelet/antiphlogistic activities evaluation

In pursuing our research on some 2,4-diamino-benzopyranopyrimidines and 2-amino-5,6-dihydrobenzo[h]quinazolines, previously reported as antiplatelet and analgesic/anti-inflammatory agents respectively, we designed and synthesized a new series of 5,6-dihydrobenzo[h]quinazoline 2,4-diamino substituted. The insertion of amino substituents at positions 2 and 4 of the benzoquinazoline scaffold resulted in compounds endowed with a potent ASA-like antiplatelet activity, combined with an anti-inflammatory activity comparable, in some cases, to that of indomethacin, used as a reference drug.

Nonsteroidal antiinflammatory agents-part 2 antiinflammatory, analgesic and antipyretic activity of some substituted 3-pyrazolin-5-ones and 1,2,4,5,6,7-3H-hexahydroindazol-3-ones

As a part of a research project on the synthesis of a number of substituted 1-(pyrimidin-2-yl)-3-pyrazolin-5-ones and 2-(pyrimidin-2-yl)hexahydroindazol-3-ones and as a result of the interesting antiinflammatory, analgesic and antipyretic activities recorded for some of these compounds, some new 3-pyrazolin-5-ones and hexahydroindazol-3-ones linked to substituted imidazolyl, pyrimidyl and tetrahydroquinazolinyl moieties were prepared and evaluated for such activity (). A structure-activity relationship (SAR) comparative study indicated that some compounds from 3-pyrazolin-5-one (2, 6-8, 10) and indazolone (18, 20, 24, 27, 29) series exhibited pronounced antiinflammatory, analgesic and antipyretic activities relative to indomethacin. Most of these compounds were found to be nearly equipotent in the antiinflammatory screen (ED(50)=16.8-19.9 mg/kg) whereas the lead compound, 2-indazolyl-4-pyrimidineacetic acid 24 (), was found to be the most potent among this series (ED(50)=9.9 mg/kg). Additionally, the most active compounds were shown to have a large safety margin (ALD(50)=3.0 g/kg, po) and devoid of ulcerogenic potentialities when administered orally at a dose of 300 mg/kg.