Computational investigation of the structure and antioxidant activity of some pyrazole and pyrazolone derivatives

Orabi, Esam A.; Orabi, Mohamed A. A.; Mahross, Mahmoud H.; Abdel-Hakim, Mohamed

doi:10.1016/j.jscs.2017.12.003

Cited by 34 publications

(31 citation statements)

References 36 publications

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“…Of their reaction mechanisms, antioxidants may transfer H or both an electron and a proton to the free radical. 6,25 It was shown that X-H (X ¼ C, N or O) bond dissociation energy (BDE) and vertical ionization potentials (IPV) can be used to compare the rate of the two mechanisms and to compare compounds' antioxidant activities. 6 BDEs are calculated as:…”

Section: Computational Detailsmentioning

confidence: 99%

“…This decrease in IPV is due to the higher stability of the radical cations in solvents as compared to gas phase. 6 Solvents affect BDEs by a maximum of 3.5 kcal mol À1 and the directionality of this change varies between compounds. For example while DMSO increases the BDE of the amine-one form of compound 1 by 1.0 kcal mol À1 , it decreases this of compound 4 by 3.4 kcal mol À1 and does not inuence this of compound 3 ( Table 1 vs. S3 †).…”

Section: Solvent Effectsmentioning

confidence: 99%

“…This indicates that the H-atom transfer mechanism is energetically more favorable than the sequential electron transfer proton transfer mechanism when these Schiff bases interact as antioxidants with free radicals. 6 Parmar et al experimentally measured the ferric reducing antioxidant power (FRAP) of compounds 1-9 and showed that compounds 4 and 1 are the strongest and weakest antioxidants.…”

Section: Antioxidant Activity Of Schiff Bases 1-9mentioning

confidence: 99%

“…1A) known as 3-pyrazolone (CH form), 4-pyrazolone (OH form), and 5-pyrazolone (NH form). 6 It was recently shown that the relative stability of these forms depends on the solvent and on substituents R 0 and R 00 , and that the presence of bulky or aromatic R 00 groups limits the formation of the CH isomer. 6 Pyrazolones in which R 00 is an acyl group (R 1 CO) were found to possess multidrug resistance-modulating activity 10 and the benzoyl derivative (R 1 ¼ Ph) was shown to be a potential antiprion agent.…”

Section: Introductionmentioning

confidence: 99%

“…6 It was recently shown that the relative stability of these forms depends on the solvent and on substituents R 0 and R 00 , and that the presence of bulky or aromatic R 00 groups limits the formation of the CH isomer. 6 Pyrazolones in which R 00 is an acyl group (R 1 CO) were found to possess multidrug resistance-modulating activity 10 and the benzoyl derivative (R 1 ¼ Ph) was shown to be a potential antiprion agent. 7 4-Acylpyrazolones represent an important class of chelating ligands known as heterocyclic b-diketones which have been employed for preparation of mono and dinuclear complexes.…”

Section: Introductionmentioning

confidence: 99%

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Tautomerism and antioxidant activity of some 4-acylpyrazolone-based Schiff bases: a theoretical study

Orabi

2018

RSC Adv.

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Section: Computational Detailsmentioning

confidence: 99%

Section: Solvent Effectsmentioning

confidence: 99%

Section: Antioxidant Activity Of Schiff Bases 1-9mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Tautomerism and antioxidant activity of some 4-acylpyrazolone-based Schiff bases: a theoretical study

Orabi

2018

RSC Adv.

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New pyrazole‐4‐carbothioamide‐based metal complexes: Synthesis, spectral characterization, computational, antimicrobial, and antitumor investigations

Ramadan

Elsamra

Bondock

2020

Applied Organom Chemis

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A series of 5‐hydroxy‐4‐(N‐substituted carbothioamide) pyrazole derivatives (HL1–HL5) and their iron(III), nickel(II), and copper(II) complexes have been synthesized. Structural elucidations of the isolated ligands and their complexes are basically accomplished by FT‐IR, 1H NMR, 13C NMR, UV–Vis, ESR, MS, and thermogravimetric analysis (TGA). The analytical data propose the stoichiometries 1:3 (M:L) for Fe(III) and 2:3 for both Ni(II) and Cu(II) complexes. The spectral data substantiate the bidentate coordination mode for all ligands towards metal ions via S and O atoms of CS of the carbothioamide group at pyrazole‐C4 and OH group at C(5) where deprotonation occurs from the enolic tautomer on chelation. Likewise, bidentate pattern of a bridged acetate group is confirmed in the case of Ni(II) and Cu(II) complexes. The magnetic moment values validate high spin octahedral geometry for Fe(III) complexes whereas the diamagnetic feature of Ni(II) complexes is in conformity with the square planar symmetry of low spin state. ESR spectra of all Cu(II) complexes support their existence in distorted square planar geometry with a considerable electron exchange between two copper ion centers of dinuclear type. TGA and DTG analysis of six complexes display their considerable thermal stability. Besides, the in vitro biological screening effects of some selected compounds are tested against various human pathogen microorganisms. Among the ligands, HL5 exhibits the greatest antibacterial activity against two Gram‐positive species (Bacillus subtilis and Staphylococcus aureus) and one Gram‐negative (Proteus vulgaris) in comparison with gentamicin drug. Furthermore, IC50 values of [Cu2(L5)3(OAc)] complex reveal its significant anticancer activity against the three tumor cell lines HCT‐116, MCF‐7, and HepG‐2 compared with imatinib and cisplatin as positive controls. Finally, the optimized structures of all ligands and their molecular electrostatic potential surfaces are established by utilizing density functional theory (DFT).

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Facile One‐Pot Three Component Synthesis, Characterization, and Molecular Docking Simulations of Novel α‐Aminophosphonate Derivatives Based Pyrazole Moiety as Potential Antimicrobial Agent

Noser,

Ibrahim,

Saad‐Allah

et al. 2023

Chemistry & Biodiversity

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An efficient method has been developed for the synthesis of novel α‐aminophosphonates (AAP) (3 a–m) through a one‐pot three‐component reaction of 1,3‐disubstituted‐1H‐pyrazol‐5‐amine, aromatic aldehydes, and phosphite using lithium perchlorate as catalyst. All newly synthesized compounds were characterized via different spectroscopic techniques. The synthesized compounds′ mode of action was investigated using molecular docking against the outer membrane protein A (OMPA) and exo‐1,3‐β‐glucanase, with interpreting their pharmacokinetics aspects. The results of the antimicrobial effectiveness of these compounds revealed a broad spectrum of their biocidal activity and this in‐vitro study was in line with the in‐ silico results. Additionally, it has been demonstrated that these compounds exhibited a minimum inhibitory concentration (MIC) with significant activity at low concentrations (7.5–30.0 mg/mL). Further, the radical scavenging (DPPH*) activity of the synthesized compounds fluctuated, with compounds 3 h, 3 a, and 3 f showing the highest antioxidant activity. Overall, the formulated compounds can be employed as antimicrobial and antioxidant agents in medical applications.

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Computational investigation of the structure and antioxidant activity of some pyrazole and pyrazolone derivatives

Cited by 34 publications

References 36 publications

Tautomerism and antioxidant activity of some 4-acylpyrazolone-based Schiff bases: a theoretical study

Tautomerism and antioxidant activity of some 4-acylpyrazolone-based Schiff bases: a theoretical study

New pyrazole‐4‐carbothioamide‐based metal complexes: Synthesis, spectral characterization, computational, antimicrobial, and antitumor investigations

Facile One‐Pot Three Component Synthesis, Characterization, and Molecular Docking Simulations of Novel α‐Aminophosphonate Derivatives Based Pyrazole Moiety as Potential Antimicrobial Agent

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