Synthesis and investigations of reactive properties, photophysical properties and biological activities of a pyrazole-triazole hybrid molecule

Innovative Pyrazole Hybrids: A New Era in Drug Discovery and Synthesis

Heterocyclic compounds that include nitrogen and their derivatives have long been regarded as excellent sources of medicinal substances. Pyrazole is a compound with two nitrogen atoms and an aromatic structure. It has several uses and intricate stereochemistry arranged in a five-membered ring. The knowledge of different pyrazole derivatives and their range of physiological and pharmacological actions has grown significantly in recent years. The scientific community has recently increasingly focused on exploring the chemistry of various pyrazole hybrids due to their enhanced biological activities. This review investigates the chemistry of these diverse pyrazole hybrids, emphasizing their synthesis and their antidiabetic, antibacterial, anticancer, antimicrobial, antioxidant, and anti-inflammatory activities. Articles published from 2014 onward with an emphasis on the last 5 years are included in this review. This review is anticipated to be useful for future investigations and innovative concepts in the pursuit of designs for creating more promising hybrids of pyrazoles.

Inherent efficacies of pyrazole-based derivatives for cancer therapy: the interface between experiment and in silico

There has been an increasing trend in the design of novel pyrazole derivatives for desired biological applications. For a cost-effective strategy, scientists have implemented various computational drug design tools to go hand in hand with experiments for the design and discovery of potentially effective pyrazole-based therapeutics. This review highlights the milestones of pyrazole-containing inhibitors and the use of molecular modeling techniques in conjunction with experimental studies to provide a view of the binding mechanism of these compounds. The review focuses on the established targets that play a key role in cancer therapy, including proteins involved in tubulin polymerization, carbonic anhydrase and tyrosine kinase. Overall, using both experimental and computational methods in drug design represents a promising approach to cancer therapy.

New benzimidazole-oxadiazole derivatives: Synthesis, α-glucosidase, α-amylase activity, and molecular modeling studies as potential antidiabetic agents

Benzimidazole-1,3,4-oxadiazole derivatives (5a-z) were synthesized and characterized with different spectroscopic techniques such as ¹ H NMR, ¹³ C NMR, and HRMS. The synthesized analogs were examined against α-glucosidase and α-amylase enzymes to determine their antidiabetic potential. Compounds 5g and 5q showed the most activity with 35.04 ± 1.28 and 47.60 ± 2.16 µg/mL when compared with the reference drug acarbose (IC₅₀  = 54.63 ± 1.95 µg/mL). Compounds 5g, 5o, 5s, and 5x were screened against the α-amylase enzyme and were found to show excellent potential, with IC₅₀ values ranging from 22.39 ± 1.40 to 32.07 ± 1.55 µg/mL, when compared with the standard acarbose (IC₅₀  = 46.21 ± 1.49 µg/mL). The antioxidant activities of the effective compounds (5o, 5g, 5s, 5x, and 5q) were evaluated by TAS methods. A molecular docking research study was conducted to identify the active site and explain the functions of the active chemicals. To investigate the most likely binding mode of the substances 5g, 5o, 5q, 5s, and 5x, a molecular dynamics simulation was also carried out.

New2-((2-(2,4-dinitrophenyl)hydrazineeylidene) derivatives: design, synthesis, in silico, and in vitro anticancer studies

A series of novel hydrazone compounds have been synthesized by the condensation of hydrazines and different substituted salicylaldehydes at a molar ratio of 1:1 in one step reaction and characterized by FT-IR, ESI-MS, 1H NMR, and single crystal x-ray diffraction. The crystal structure of the compound shows a trans configuration around the C = N bond and triclinic system with P -1/-p 1. Synthesized compounds were screened for cytotoxicity activities against A375 (melanoma), HT-29 (Colon), and A549 (lung) cancer cell lines. Among them, compound 2 exhibited the highest cytotoxic effect against the A375 cell line (IC50 = 0.30 µM) and HT-29 cell line (1.68 µM), compared to those of apatinib as a reference standard drug (0.28, 1.49 µM, respectively). The cytocompatibility assay on the L929 normal cell line and the hemolysis assay on human RBC were used to validate the non-toxic action. From DFT calculation, the various parameters such as HOMO-LUMO energies, Hirshfeld, and MEP have been studied. Furthermore, in silico molecular docking with three receptors was studied. Among four compounds, compound 2 has the lowest binding energy against cyclin dependent kinase (ΔGb = -9.3 kcal/mol). In addition to this, molecular dynamics (MD) simulation was also performed. Based on this study, these novel hydrazones can be considered a promising anticancer agent due to their potent cytotoxicity activities and computational analysis.Communicated by Ramaswamy H. Sarma.

Evaluation of the Chemical Composition, Antioxidant and Antidiabetic Activity of Rhaponticoides iconiensis Flowers: Effects on Key Enzymes Linked to Type 2 Diabetes In Vitro, In Silico and on Alloxan-Induced Diabetic Rats In Vivo

Diabetes mellitus (DM) is one of the globally worst killer diseases. In this study, the in vitro and in vivo antidiabetic activity and antioxidant capacity were determined and the phytochemical analyses were carried out on flower extract and sub-extracts of Rhaponticoides iconiensis. The in vitro antidiabetic activity was tested with α-amylase and α-glucosidase enzyme inhibition methods and an in vivo OGTT test in healthy and alloxan-induced rats. Although, the antioxidant activity was investigated with DPPH●, ABTS●+ and FRAP tests, the phytochemical composition analysis was carried out by LC-MS/MS. The highest α-glucosidase and α-amylase activity even from positive control acarbose were found in the ethyl acetate sub-extract of R. iconiensis (IC50 = 11.737 ± 0.823 µg/mL and 84.247 ± 0.721 µg/mL, respectively). This sub-extract also was active according to the results of in vivo tests. Moreover, the highest antioxidant activity on DPPH● (IC50 = 0.126 ± 0.002 mg/mL), FRAP (at a concentration of 1 mg/mL equivalent to 3112.052 ± 2.023 mmol Fe2+) and ABTS+● (at a concentration of 0.5 mg/mL equivalent to 0.608 ± 0.005 µM Trolox) tests. In addition, LC-MS/MS analyses of the active sub-extract revealed mainly the presence of patuletin, patuletin 3,7-diglucoside, naringin and 3,4-dicaffeoylquinic acid detected in the active sub-extract. In silico molecular docking and dynamics simulations studies were performed on these compounds with α-amylase and α-glucosidase enzymes for protein-ligand interactions and stability.

Synthesis, photophysical and nonlinear optical properties of push-pull tetrazoles

A 2,5-disubstituted tetrazole with p-nitrophenyl and 3-pyridyl units as acceptors (1a), and three push–pull tetrazoles with p-nitrophenyl as an acceptor and phenyl (1b), 2-(dibenzo[b,d]furan-4-yl) (1c), and 4-(N,N-diphenylamino)phenyl (1d) as donor groups, were synthesized by copper-catalyzed aerobic C–N coupling of p-nitrophenyl tetrazole with appropriately substituted aryl boronic acids. The absorption and emission spectra of 1a–c showed minimal dependence on the polarity of the solvent; however, in the case of 1d a blue shift was noted in the longest absorption band (λ₁) as the polarity increased. The fluorescence intensity of the title compounds was found to be solvent-dependent; however, no apparent correlation to solvent polarity could be established. The absorption and emission characteristics of 1a–d were also influenced by the nature of the substituent as 1d, bearing a strong electron donating 4-(N,N-diphenylamino)phenyl group, displayed a significant red shifted absorption (λ₁) as well as emission (λ_em) bands compared to other compounds. Time dependent density functional calculations (CAM-B3LYP/6-311++G**) revealed that the longest wavelength band (λ₁) is associated with an intramolecular charge transfer (ICT) from HOMO/HOMO-1/HOMO-2 → LUMO/LUMO+1 in these molecules. The first hyperpolarizability values, β_HRS, of 1a–d were measured using the solution-based hyper-Rayleigh scattering technique using a femtosecond Ti:Sapphire laser and the highest NLO activity was measured for 1d with the greatest push–pull characteristics. A strong correlation was observed between the calculated hyperpolarizability (β_tot) and experimentally measured values (β_HRS).

A 2,5-disubstituted tetrazole with a p-nitrophenyl unit as an acceptor and a 4-(N,N-diphenylamino) phenyl group as a donor exhibits strong push–pull characteristics and displays high NLO activity.