Synthesis of new pyrazolyl-1,3-diazabicyclo[3.1.0]hexe-3-ene derivatives

Some Thiazolopyrimidine Derivatives: Synthesis, DFT, Cytotoxicity, and Pharmacokinetics Modeling Study

A pyrimidinethione candidate carrying pyrazole and thiophene scaffolds was produced by a Biginelli cyclocondensation reaction of a pyrazolecarbaldehyde with pentan-2,4-dione and thiourea. To create some heteroannulated thiazolopyrimidines, the pyrimidinethione was subjected to cyclocondensation reactions with ethyl chloroacetate, 1,2-dibromoethane, chloroacetonitrile, and oxalyl chloride. A DFT simulation was performed for a frontier-orbital analysis to determine the molecular geometry. Among the products, 6-acetyl-7-methyl-5-[1-phen­yl-3-(2-thienyl)-1H-pyrazol-4-yl]-5H-[1,3]thiazolo[3,2-a]pyrimidine-2,3-dione displayed the highest softness and the lowest energy gap in the DFT calculations. Moreover, it had the highest electrophilicity index, suggesting possible biological impacts. The compounds obtained were evaluated against cell lines of breast adenocarcinoma (MCF7) and hepatocellular carcinoma (HepG2) as antiproliferative agents. A simulation of the molecular docking of our compounds with the epidermal growth factor receptor demonstrated the rationality of our design and identified the binding mode. A model pharmacokinetics analysis showed that the products have the expected and desirable drug-like and bioavailability properties.

Molecular docking and simulation studies of some pyrazolone-based bioactive ligands targeting the NF- κ B signaling pathways

NF-κB has become a predominant regulator responsible for multiple physiological and pathological processes. NF-κB signaling pathway has canonical and non-canonical components which strategize the cancer-related metabolic processes. Non-canonical NF-κB pathways are known to contribute towards the chemoresistance of cancer cells. Consequently, NF-κB can be utilized as a potential therapeutic target for modifying the behaviour of tumor cells. In view of this, we herein report a series of pyrazolone-based bioactive ligands that potentially target NF- κB and, thereby, unveil their anticancer properties. The pharmacological screening of the synthesized compounds were carried out using various virtual screening techniques. The anticancer studies of synthesized pyrazolones showed that APAU exhibited the most potent effect against the MCF-7 cells with an IC50 value of 30 μg/ml. Molecular docking studies revealed that the pyrazolones inhibited cell proliferation by targeting the NFκB signaling pathway. The molecular dynamics simulation studies predicted the stability and flexibility of pyrazolone-based bioactive ligands.

Synthesis, biological evaluation, migratory inhibition and docking study of Indenopyrazolones as potential anticancer agents

Some bioactive derivatives of indeno[1,2- c ]pyrazolones were synthesized through the reaction of phenylhydrazine, different aldehydes and indan-1,2,3-trione at room temperature in acetonitrile. Analytical and spectroscopic studies have confirmed the structural characteristics of the synthesized compounds. In addition, the target compounds were screened for the in-vitro antiproliferative properties against the B16F10 melanoma cancer cell line by the standard MTT assay. The effect on inflammatory marker cyclooxygenase 2 and matrix metalloproteinase 2, 9 was also checked to determine the anti-inflammatory and anti-cell migratory properties of these compounds. The final compounds were also tested for their tyrosinase inhibitory activity. Among all compounds, screened for anticancer activity, three compounds 4e , 4f and 4h reduced the cell proliferation significantly comparable to that of the positive standard drug erlotinib (IC 50 = 418.9±1.54 µM) with IC 50 values ranging from 20.72-29.35 µM. The compounds 4c-4h decreased the COX-2 expression whereas the MMP 2, 9 expressions were significantly reduced by 4a , 4b and 4h . This was confirmed by molecular docking studies, as 4e , 4f and 4h displayed good interactions with the active site of BRAF protein. The compounds 4b , 4f and 4h exhibited moderate tyrosinase inhibition effect as compared to α-MSH. Collectively, compound 4h can be considered as a candidate for further optimization in the development of anticancer therapies based on the results of biological investigations in this study.

Synthesis, characterization and application of chitosan conjugated heterocyclic compounds

Derivatives of formyl pyrazole were synthesized by the reaction of acetophenone, 4-methyl acetophenone, 3-acetyl furan, 3-acetyl thiophen and phenyl hydrazine derivatives. The product was treated with Vilsmeier reagent producing different formyl pyrazole derivatives which were characterized by FT-IR, 1HNMR, Elemental analysis and Mass spectroscopy. The formyl pyrazole derivatives were reacted with chitosan to produce chitosan/ pyrazole Schiff base. These Schiff bases were characterized by FT-IR and TGA.The antimicrobial activity of chitosan/ pyrazol Schiff base (CSB) was evaluated against Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus), gram negative bacterium (Escherichia coli) and fungus (Aspergillus niger). Results indicated agood inhibitory activity for CSB-14 when tested against B.cereus that gave inhibition zone of 7.5 ± 0.6 (mm), however CSB-18 gave a pronounced inhibitory activity against S. aureus and recorded 25 ± 2.0 (mm). All synthesized derivatives have no inhibitory activity against Gram negative E. coli. CSB-14, and CSB-15 exhibited inhibitory activity against tested A. niger that was used as a fungal model which gave 19 ± 0.9 and 18 ± 1.0 inhibition zone (mm) respectively. Thus, these results showed that, functionalization of chitosan with the hetero-cyclic compounds created biological activities of the synthesized derivatives; hence the synthesized pyrazole derivatives have not recorded any inhibitory activity before its immobilization onto chitosan.

Synthesis and biological evaluation of 3,5-diaryl-pyrazole derivatives as potential antiprostate cancer agents

Prostate cancer is the most frequently diagnosed tumor in men and the second leading cause of cancer-associated mortality in most developed countries. 3,5-Diaryl substituted pyrazole derivatives (20-28) were prepared starting from related chalcones and biologically evaluated for in vitro growth inhibition activity against PC3 and DU145 human prostate cancer cell lines. Compounds 23, 26, and 28 were found to be more potent as compared to the other halogen-substituted derivatives. Especially, the 2-bromo-substituted pyrazole derivative (26) was found to be more potent against PC3 and DU145 cells. Epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor 2 (VEGFR2) are known to be expressed in DU145 and PC3 cancer cells. The binding mode of the most selective compound 26 toward EGFR and VEGFR2 was investigated by employing docking simulations based on GLIDE standard precision (-5.912 and -6.949 kcal/mol, respectively).

Pyrazoles and Pyrazolines as Anti-Inflammatory Agents

The five-membered heterocyclic group of pyrazoles/pyrazolines plays important role in drug discovery. Pyrazoles and pyrazolines present a wide range of biological activities. The synthesis of the pyrazolines and pyrazole derivatives was accomplished via the condensation of the appropriate substituted aldehydes and acetophenones, suitable chalcones and hydrazine hydrate in absolute ethanol in the presence of drops of glacial acetic acid. The compounds are obtained in good yields 68-99% and their structure was confirmed using IR, ¹H-NMR, ¹³C-NMR and elemental analysis. The novel derivatives were studied in vitro for their antioxidant, anti-lipid peroxidation (AAPH) activities and inhibitory activity of lipoxygenase. Both classes strongly inhibit lipid peroxidation. Compound 2g was the most potent lipoxygenase inhibitor (IC₅₀ = 80 µM). The inhibition of the carrageenin-induced paw edema (CPE) and nociception was also determined, with compounds 2d and 2e being the most potent. Compound 2e inhibited nociception higher than 2d. Pyrazoline 2d was found to be active in a preliminary test, for the investigation of anti-adjuvant-induced disease (AID) activity. Pyrazoline derivatives were found to be more potent than pyrazoles. Docking studies of the most potent LOX inhibitor 2g highlight hydrophobic interactions with VAL126, PHE143, VAL520 and LYS526 and a halogen bond between the chlorine atom and ARG182.

Review: biologically active pyrazole derivatives

Nitrogen-containing heterocyclic compounds and their derivatives have historically been invaluable as a source of therapeutic agents.