Synthesis and antiviral activity of some pyrrolonyl substituted heterocycles as additives to enhance inactivated Newcastle disease vaccine

Antiviral activity of pyrazole derivatives bearing a hydroxyquinoline scaffold against SARS-CoV-2, HCoV-229E, MERS-CoV, and IBV propagation

The ongoing global threat posed by coronaviruses necessitates the urgent development of effective antiviral agents. In this study, we investigated the potential of hydroxyquinoline-pyrazole candidates as antiviral agents against a range of coronaviruses, including SARS-CoV-2, MERS-CoV, and HCoV-229E. Molecular docking studies were conducted to assess the binding affinity of the synthesized compounds to key viral proteins. The compounds were prepared via condensation reactions of a pyrazolylhydrazide derivative with 2-chloro-3-formylquinoline, yielding hydrazone and pyrrolone derivatives. The cytotoxicity of compounds was evaluated using Vero E6 cells, and their antiviral activity was assessed via plaque reduction assays and viral inhibition assays using hydroxychloroquine as a positive control antiviral drug. The results revealed promising antiviral activity of the synthesized compounds against all tested coronaviruses, with selectivity indices indicating their potential as selective antiviral agents. Notably, the compounds exhibited potent inhibition of SARS-CoV-2 at lower concentrations, highlighting their promise as therapeutic candidates against this highly pathogenic virus. Likewise, the modeling pharmacokinetics approach showed its appropriate drug-likeness and bioavailability assets. These findings underscore the importance of hydroxyquinoline-pyrazole derivatives as potential antiviral agents against diverse coronaviruses, providing valuable insights for further therapeutic development.

Some pyrimidohexahydroquinoline candidates: synthesis, DFT, cytotoxic activity evaluation, molecular docking, and in silico studies

Some hexahydroquinoline candidates were prepared by reacting 2-amino-3-cyano-1-cyclohexylhexahydroquinoline with oxalyl chloride and triethyl orthoformate. The computational chemical approach agreed with the product-testing results. The produced substances were examined in vitro for their antiproliferative activity against liver carcinoma (HepG2), breast adenocarcinoma (MCF7), prostate cancer (PC3), and colon cancer (HCT116) cell lines. The highest potency against the four cell lines was exhibited by hydrazide, thiosemicarbazide, and thiazolidinone derivatives. The best docking score was presented by thiosemicarbazide and thiazolidinone derivatives as they showed the highest binding to the Mcl-1 enzyme with binding energies of -8.97 and -8.90 kcal mol-1, respectively, which were higher than that of the co-crystallized ligand (LC3) with a binding energy of -8.74 kcal mol-1. Besides, the modeling pharmacokinetics disclosed their desirable drug-likeness and oral bioavailability characteristics.

N-Heterocycles as Promising Antiviral Agents: A Comprehensive Overview

Viruses are a real threat to every organism at any stage of life leading to extensive infections and casualties. N-heterocycles can affect the viral life cycle at many points, including viral entrance into host cells, viral genome replication, and the production of novel viral species. Certain N-heterocycles can also stimulate the host's immune system, producing antiviral cytokines and chemokines that can stop the reproduction of viruses. This review focused on recent five- or six-membered synthetic N-heterocyclic molecules showing antiviral activity through SAR analyses. The review will assist in identifying robust scaffolds that might be utilized to create effective antiviral drugs with either no or few side effects.

Synthesis, antileishmanial, antimalarial evaluation and molecular docking study of some hydrazine-coupled pyrazole derivatives

Pyrazole-bearing compounds are known for their diverse pharmacological effects including potent antileishmanial and antimalarial activities. Herein, some hydrazine-coupled pyrazoles were successfully synthesized and their structures were verified by employing elemental microanalysis, FTIR, and 1H NMR techniques. The in vitro antileishmanial and in vivo antimalarial activities of the synthesized pyrazole derivatives (9-15) were evaluated against Leishmania aethiopica clinical isolate and Plasmodium berghei infected mice, respectively. The result revealed that compound 13 displayed superior antipromastigote activity (IC50 = 0.018) that was 174- and 2.6-fold more active than the standard drugs miltefosine (IC50 = 3.130) and amphotericin B deoxycholate (IC50 = 0.047). The molecular docking study conducted on Lm-PTR1, complexed with Trimethoprim was acquired from the Protein Data Bank (PDB ID:2bfm), justified the better antileishmanial activity of compound 13. Furthermore, the target compounds 14 and 15 elicited better inhibition effects against Plasmodium berghei with 70.2% and 90.4% suppression, respectively. In conclusion, the hydrazine-coupled pyrazole derivatives may be considered potential pharmacophores for the preparation of safe and effective antileishmanial and antimalarial agents.

Triphosgene and Triphenylphosphine Oxide-Mediated Cascade Heterocyclization of N-Acylated Anilines: One-Pot Synthesis of 2,4-Dichloroquinolines

A one-pot cascade chlorination/heterocyclization strategy has been developed for the synthesis of 2,4-dichloro-substituted quinolines from acylated anilines using triphosgene and triphenylphosphine oxide. Obviating the conventional harsh conditions of chlorination, synthetic useful quinolines with moderate to good yields were obtained through this reaction. The mechanism study exhibited that the formation of a β-enamine intermediate plays a vital role in the generation of the final product.

Synthesis and antioxidant, antimicrobial, and antiviral activity of some pyrazole-based heterocycles using a 2(3H)-furanone derivative

Some pyrazole-based heterocycles such as pyrrolone, pyridazinone, and imidazole derivatives were synthesized utilizing the pyrazolyl-2(3H )-furanone derivative 3 , which was obtained in a good yield via Perkin condensation of 5-chloro-4-formyl-3-methyl-1-phenylpyrazole with 3-(4-methylbenzoyl)propionic acid in the presence of cyclo-dehydrating agent (sodium acetate and acetic anhydride). Also, the acid hydrazide obtained was reacted with some carbonyl reagents such as acetic anhydride, benzoyl chloride, 4-chlorobenzaldehyde, and 1,3-diphenyl-4-formylpyrazole, aiming to achieve new pyrrolone derivatives. The antioxidant, antimicrobial, and antiviral activity screening of some synthesized compounds demonstrated that some of them offered strong potencies. An experimental trial was undertaken to explore the effect of different substances and applied against avian influenza HPAI-H5N1 (AIV) to evaluate the antiviral replication in specific pathogen-free chicken embryos. All the compounds were screened for their antimicrobial activities, and most of tested compounds showed potent inhibition growth activity toward Haemophilus (Gram-negative bacteria), Staphylococcus aureus (Gram-positive bacteria), and Candida albicans fungus. Upon antimicrobial screening, it was observed that the majority of the compounds were found to be active against Staphylococcus aureus , Haemophilus , and Candida albicans as compared to standard drugs. This experiment shows the potential usage of these compounds as antiviral agents and can be considered as a viable means to control the economically important avian influenza of poultry. These compounds can thus be recommended for their antiviral, antibacterial, and antifungal property and can very well be used as immunostimulants.

Heterocycles in Breast Cancer Treatment: The Use of Pyrazole Derivatives

Among the aromatic heterocycle rings, pyrazole -a five-membered ring with two adjacent nitrogen atoms in its structure has been postulated as a potent candidate in the pharmacological context. This moiety is an interesting therapeutic target covering a broad spectrum of biological activities due to its presence in many natural substances. Hence, the potential of the pyrazole derivatives as antitumor agents has been explored in many investigations, showing promising results in some cases. In this sense, breast cancer, which is already the leading cause of cancer mortality in women in some countries, has been the topic selected for this review, which covers a range of different research from the earliest studies published in 2003 to the most recent ones in 2021.

Synthesis, SAR studies, and insecticidal activities of certain N-heterocycles derived from 3-((2-chloroquinolin-3-yl)methylene)-5-phenylfuran-2(3H)-one against Culex pipiens L. larvae

An acid hydrazide derivative was synthesized and transformed into a variety of valuable N-heterocycles such as pyridazinone, oxadiazole, triazolopyridazinone, and triazole derivatives via reactions with certain carbon electrophiles such as 4-methoxybenzaldehyde, indole-3-carbaldehyde, pentan-2,4-dione, and carbon disulfide. The chemical structures of all prepared compounds were verified via their analytical and spectroscopic data. The insecticidal activity of the N-heterocycles was evaluated against field and lab strains of the third larval instar of Culex pipiens. All tested compounds exhibited higher larvicidal activity against the lab strains compared to the field strains, with dissimilar ratios. The obtained results demonstrate that the high toxicity achieved by oxadiazole followed the order of furanone, pyridazinone and hydrazide, with lower LC₅₀ values of the hydrazone and N-acetylpyridazinone derivatives compared to that of imidacloprid. Interestingly, these compounds are promising agents for insect pest control, especially since they are insoluble in water and can overcome the disadvantages of neonicotinoid applications in pest management programs.

A new series of N-heterocycles including pyridazinone, oxadiazole, triazolopyridazinone, and triazole derivatives were synthesized from the acid hydrazide via its reaction with certain carbon electrophiles.

Yb(OTf)3-Mediated Annulation of Cyclopropane-1,1-dicarbonitriles with 2-Aminobenzaldehydes for Synthesis of Polysubstituted Quinolines

A Yb(OTf)₃-mediated annulation of cyclopropane-1,1-dicarbonitriles and 2-aminobenzaldehydes for the synthesis of polysubstituted quinolines in generally good yields was investigated. In the cascade reaction, the protocol includes ring opening, intermolecular nuclophilic addition, intramolecular nuclophilic addition, and demalononitrile aromatization, in which the malononitrile group serves as a deciduous directing group mediated by Yb(OTf)₃.

Synthesis, DFT, and eco-friendly insecticidal activity of some N-heterocycles derived from 4-((2-oxo-1,2-dihydroquinolin-3-yl)methylene)-2-phenyloxazol-5(4H)-one

A new series of nitrogen heterocycles encompassing a quinoline scaffold such as imidazolone, benzimidazole, triazinone, triazole, and thiazole derivatives was synthesized utilizing the readily obtainable building block synthon, 4-((2-oxo-1,2-dihydroquinolin-3-yl)methylene)-2-phenyloxazol-5(4H)-one (3). It was interesting that the fused heterocycle, pyranoquinoline derivative 15 was successfully synthesized by different routes of reactions. The synthesized compounds were evaluated for their insecticidal activity and compounds 6, 17, and 20 were the most potent against both Mythimna separata and Nilaparvata lugens. The DFT study was performed for the most potent compounds.

Synthesis, antiproliferative activity, and molecular docking of some N‐heterocycles bearing a pyrazole scaffold against liver and breast tumors

A new series of some 1,3‐diphenylpyrazole‐based heterocycles were constructed from 2‐cyano‐3‐(1,3‐diphenyl‐1H‐pyrazol‐4‐yl)propenoyl chloride (1). The titled acid chloride was submitted to react with mono‐nucleophilic reagents, including oxygen, sulfur, or nitrogen, to afford new acrylate, thioacrylate, and acrylamide derivatives, respectively. Meanwhile, condensation of 1 with some 1,2‐ and 1,3‐binucleophiles led to the construction of oxadiazepine, pyridopyrimidine, and thiadiazolopyrimidine derivatives (16, 18, 20, 23). In turn, two benzoxazinone derivatives (27, 28) were synthesized upon treating 1 with substituted anthranilic acids followed by heating with acetic anhydride. The antiproliferative activity of the compounds developed against two tumors (HePG2 and MCF7) was evaluated. Compounds 4, 6, 11, 25, and 26 exhibited strong activity and compounds 3, 5, 16, 18, 27, and 28 exhibited moderate activity. A molecular modeling study was conducted by utilizing molecular modeling environment to test the binding free energies of the studied compounds toward human cyclin‐dependent kinase 2. The compounds, 4, 25, and 26, displayed the best docking score. The orientation and hydrogen bond pattern of these compounds in the active site correspond to that of PNU‐292137, which had been approved as a selective CDK2 inhibitor.