Design, synthesis, characterization, and antioxidant activity studies of novel thienyl-pyrazoles

Abstract

In a sustained search for novel and effective antioxidants, a potential therapeutic leads against renal, and neurological disorders. Amongst the heterocycles, pyrazole and their derivatives have been extensively studied for their biological potencies, particularly to a larger extent for their antioxidant properties. Although many of pyrazole derivatives displayed antioxidant activities, still there is a need of developing efficient protocol for their synthesis, involving ecofriendly conditions, molecules of greater antioxidant efficacy and lesser toxicity, etc. In this context, the current study presents an amberlyst-15 catalysed efficient synthesis of 2-pyrazoline derivatives, 5 ( a - g ) via (3 + 2) annulation of chalcones with phenylhydrazines. Structure proofs of new pyrazoles offered by spectral studies, and the molecular structure of compound 5d of the series by crystallographic studies, which revealed an intra molecular hydrogen bond interactions (C–H⋯N type), and stabilization by C–H...π and π---π molecular interactions. Of the series, compounds 5g and 5h show excellent DPPH (IC 50 = 0.245 ± 0.01, and 0.284 ± 0.02 μM); and hydroxyl (IC 50 = 0.905 ± 0.01, and 0.892 ± 0.01μM) radical scavenging activities comparable with respective controls, ascorbic acid (IC 50 = 0.483 ± 0.01μM) and BHA (IC 50 = 1.739 ± 0.01μM). The molecular docking and ADME/Tox studies indicate that, these compounds have good antioxidant activity through π-π stacking with Catalase via Try337 and Phe140, and therefore, might be lead antioxidants for further study.

Synthesis, in silico studies and biological screening of (E)-2-(3-(substitutedstyryl)-5-(substitutedphenyl)-4,5-dihydropyrazol-1-yl)benzo[d]thiazole derivatives as an anti-oxidant, anti-inflammatory and antimicrobial agents

“…The thin-layer chromatography (TLC) was fascinated for observing the reaction progress. FT-IR (Diffuse Reflectance Method (DRS) -8000A, Shimadzu, Japan) spectrophotometer was utilized for recording infrared spectra and the Bruker Avance III, 400 MHz NMR spectrometer was employed for nuclear magnetic resonance spectra ( 1 H NMR, 13 C NMR, Chemical shift δ values-ppm). DPPH (High Media), Nutrient broth and Sabouard dextrose broth (Hi-Media) have been used for in vitro biological studies.…”

“…AutoDock Vina, the advanced docking program was employed to estimate the binding charcaterstics of synthesized compounds into the active sites of target protein [38,43]. The crystal structures of PDB: 6COX Cyclooxygenase-2 (prostaglandin synthase-2) complexed with a selective inhibitor, SC-558 IN I222 space group) [44], PDB: 2CAG (Catalase compound II) [13], PDB:1U4G, Elastase of P. aeruginosa with an inhibitor [45] and PDB:1EA1 (cytochrome P450 14 alpha-sterol demethylase (CYP51) from Mycobacterium tuberculosis in complex with fluconazole [46] were retrieved from the protein data bank (www. rcsb.…”

“…There are a huge number of heterocyclic compounds known, and the number is continually growing. Molecules containing benzothiazole moiety have broad range of biological action, encompassing antiviral [7], antibacterial [8,9], anti-inflammatory [10], antidiabetic [11], analgesic [12], antioxidant [13,14], antidepressant [15], anticonvulsant [16], antianginal [17], anticancer [18], immunomodulatory characteristics [19], antihelmintic [20], antimalarial [21], fungicidal [22][23][24], insecticidal (Melaku et al [25]) and herbicidal properties [26][27][28].…”

Dihydropyrazole Derivatives Act as Potent α-Amylase Inhibitors and Free Radical Scavengers: Synthesis, Bioactivity Evaluation, Structure–Activity Relationship, ADMET, and Molecular Docking Studies

“…Hence, diabetes complications can be controlled by a careful control of free radicals as well as by organic reactive species (ROS) generation . Given the current situation, medicinal chemists are looking for novel drug candidates to act as better antioxidants as well as to safely treat DM patients …”

“…19 Given the current situation, medicinal chemists are looking for novel drug candidates to act as better antioxidants as well as to safely treat DM patients. 20 Dihydroyrazole is an important heterocyclic scaffold in medicinal chemistry 21 and has received remarkable attention due to its diverse range of medicinal and pharmacological potentials 22 such as antimalarial, 23 antimicrobial, 24 anticancer, 25 antiviral, 26 antioxidant, 27 antidepressant, 28 antidiabetic, 29 antimycobacterial, 30 anti-HIV, 31 and anticonvulsant. 32 Furthermore, it has been found that dihydropyrazole compounds demonstrate remarkable inhibitory activities against the cancer cell line, 33 heptosyltransferase, 34 and accumulation of the prion protein.…”