Search

In this work, three N'-arylidene-5-phenyl-1H-pyrazole-3-carbohydrazide (3a-3c), derivatives have been synthesized and fully characterized by IR, 1H & 13C NMR and ESI-MS using experimental and theoretical methods. Theoretical calculations were carried out by DFT/B3LYP method using 6-311++G(d,p) basis set. For theoretical IR, 1H & 13C NMR (with GIAO method), MEP, HOMO-LUMO energies analyses of compounds 3a-3c were performed over the optimized structures. All newly synthesized compounds were screened for their cytotoxicity, proylenpeptidase and α-glucosidase inhibitory activities. Compounds 3c showed significant anticancer activity against lung cancer cell line (H460) with the IC50 value 0.15 ± 0.01 µM. The other compounds exhibited prolyl endopeptidase (PEP) activity. Compounds 3a and 3c have demonstrated a potent α-glucosidase inhibitory activity with the IC50 value 360.4 ± 0.7 µM and 370.3 ± 1.17 µM, respectively. Furthermore, in-silico based molecular docking study was performed between the title ligands and lung cancer cell line-H460 protein: 1M17. The best affinity bond was observed between compound 3c and the protein 1M17 with an energy of −8.6 (kcal/mol), an inhibition constant of 0.496769 μM and an active hydrogen bond to three.

Porphyrins are an important class of ligands with a tremendous ability to capture metal ions closely related to the rich coordination chemistry of porphyrins. Herein we use this characteristic to develop silica gel grafted derivatives for water remediation applications. Therefore, two porphyrin derivatives, one with three and the other with four mercaptopyridyl units were grafted on silica gel functionalized with 3-aminopropyltriethoxysilane. The new adsorbents Si3PyS and Si4PyS were characterized using a suitable set of techniques confirming the covalent attachment of the porphyrins to the silica surface. Additionally, microscopy and N2 adsorption analysis confirmed the structural integrity and preservation of the mesoporous structure of Si during surface modification. The results show that both hybrid materials exhibit good chemical and thermal stability and an outstanding Cu2+ removal capability, with a chemical adsorption capacity of 176.32 mg g–1 and 184.16 mg g–1, respectively. These materials have also been used in real water and industrial wastewater samples with minimal interference in their adsorption capabilities. Density Functional Theory calculations were performed to confirm the good performance of the hybrid materials Si3PyS and Si4PyS towards metal ions. The functionalization of silica surface with porphyrin-based ligands bearing additional binding motifs drastically improves the adsorption capability of the new hybrids towards metal ions. The presence of pyridyl units brings a meaningful advantage, since both porphyrin core and appended pyridyl groups are able of binding Cu2+ ions with high affinity, contributing to the enhancement of the chelating features of the adsorbents prepared when compared with other ligands supported in silica-based materials. published

This study represents the first explorative investigation on the supramolecular structural diversity in Hg(II) coordination chemistry with triazole-thiourea ligands leading to a variety of mononuclear, binuclear, and coordination polymers: {[Hg(L1)2(L1–)2]} (1), {[Hg2(L1)2(μ2-I)2I2]·DMSO} (2), {[Hg(L2)(μ2-I)I]·MeOH}∝ (3), {[Hg2(μ-L3–)4]}∝ (4), {[HgCl(L4–)L4]·MeOH} (5), {[Hg2(L4)2(μ2-I)2(I)2]·2MeOH} (6), {[Hg2(μ2-L5–)4]}∝ (7), {[Hg2(μ2-Cl)2(L6–)2(L6)2]} (8), {[Hg2(μ2-Br)2(L6–)2(L6)2]} (9), and {[Hg2(μ2-I)2(L6–)2(L6)2]} (10). A reaction mechanism was suggested for the unexpected ligand rearrangement occurring in {[Hg2I3(μ3-L5′)]}∝ (11). The ligands were fully characterized including by X-ray crystallography and computational means. This includes six new triazole-thiourea based ligands, namely, 1-R-3-(4H-1,2,4-triazol-4-yl)thiourea (where R = methyl (L1), ethyl (L2), propyl (L3), isopropyl (L4), and its polymorph (L4-poly), allyl (L5), ethyl acetate (L6), and its solvate (L6_MeOH)). Under UV light excitation, 7, 10, and 11 exhibit visible photoluminescence of wide origin, ranging from ligand-centered (LC) fluorescence combined with organic-ligand-to-metal charge transfer (LMCT) emissive states in 7 and 10, up to halide-to-metal charge transfer (XMCT) combined with halide-to-ligand charge transfer (XLCT) emissive states in 11. The variable emission mechanisms in the obtained coordination polymers were elucidated by experimental proofs confronted with theoretical calculations of the electronic densities of states, proving that Hg(II) halide coordination polymers involving flexible 1,2,4-triazole-based ligands form a promising class of luminescent molecular materials.

A new pyrazole ligand, N,N-bis(2(1′,5,5′-trimethyl-1H,1′H-[3,3′-bipyrazol]-1-yl)ethyl)propan-1-amine (L) was synthesized and characterized by 1H-NMR, 13C-NMR, FT-IR and HRMS. The coordination ability of the ligand has been employed for the construction of a new family of coordination complexes, namely: [Cu2LCl4] (1), [ML(CH3OH)(H2O)](ClO4)2 (MII = Ni (2), Co (3)) and [FeL(NCS)2] (4). The series of complexes were characterized using single-crystal X-ray diffraction, HRMS, FT-IR and UV-visible spectroscopy. Moreover, the iron(II) analogue was investigated by 57Fe Mössbauer spectroscopy and SQUID magnetometry. Single-crystal X-ray structures of the prepared complexes are debated within the framework of the cooperative effect of the hydrogen bonding network and counter anions on the supramolecular formations observed. Furthermore, within the context of biological activity surveys, these compounds were reviewed against different types of bacteria to validate their efficiency, including both Gram-positive as well as Gram-negative bacteria. Enhanced behaviour towards Fusarium oxysporum f. sp. albedinis fungi, were detected for 1 and 4.

This study aims to explore the inhibitory action of certain derivatives of Schiff’s base, namely 4-(pyridin-2-ylimino) pentan-2-one (CE5),4-(pyrimidin-2-ylimino) pentan-2-one (CE4) and 4-((1H-tetrazol-5-yl) imino) pentan-2-one (CE20) against mild steel (MS) corrosion in 1 M HCl by the gravimetric, stationary and transient method. For additional information on the inhibitory properties of the studied compounds, scanning electron microscopy (SEM) and functional density theory (DFT) calculations were also performed. The effectiveness of the Schiff’s base derivatives studied follows the order: CE20 > CE4 > CE5. The electrochemical impedance curves show that the corrosion reaction is controlled by a charge transfer process, while the potentiodynamic polarization curves indicate that the synthesized compounds act as a mixed-type inhibitor. The adsorption process follows the Langmuir isotherm. Kinetic, as well as thermodynamic parameters, were calculated and discussed. The increase in EHOMO and decrease in gap energy ΔEgap lead to an increase in the inhibition efficiency. Results obtained from quantum chemical studies are in good agreement with quantum chemical parameters and experimental inhibition efficiencies.

The complexes: [CoL2](ClO4)2 (1), [FeL2](ClO4)2 (2), [NiL2](ClO4)2 (3) and [MnLCl2] (4), with L = diethyl-1,1′-(pyridine-2,6-diyl)bis(5-methyl-1H-pyrazole-3-carboxylate), were synthesized and fully characterized. Structural analysis revealed two distinct patterns influenced by the counter ions where L acts as a tridentate chelating ligand. The in vitro antitumor activity of L and L′ (diethyl 2,2′-(pyridine-2,6-diylbis(5-methyl-1H-pyrazole-3,1-diyl)) diacetate) as well as their metal complexes, was tested by the measurement of their cytostatic and cytotoxic properties towards the blood cancer mastocytoma cell line P815. We have also investigated their interactions with the antioxidant enzyme system. As a result, [MnL′Cl2] (1′) exhibited the strongest activity compared to reference cis-platin with no cytotoxicity towards normal cells PBMCs (Peripheral Blood Mononuclear Cells). On the other hand, the antioxidant enzyme activity showed that the efficiency of metal complex 1′ against P815 tumor cells was via the rise in the SOD activity and inhibition of CAT enzyme activity. This proof of concept study allows disclosure of a new class of molecules in cancer therapeutics.

In the present study, we report the design and synthesis of new derivatives of the β-keto-enol grafted on pyridine and furan moieties (L 1 -L 11 ). Structures of compounds were fully confirmed by Fourier transform infrared spectroscopy (FT-IR), 1H NMR, 13C NMR, electrospray ionization/liquid chromatography-mass spectrometry (ESI/LC-MS), and elemental analysis. The compounds were screened for antifungal and antibacterial activities (Escherichia coli, Bacillus subtilis, and Micrococcus luteus). In vitro evaluation showed significant fungicidal activity for L 1 , L 4 , and L 5 against fungal strains (Fusarium oxysporum f.sp albedinis) compared to the reference standard. Especially, the exceptional activity has been demonstrated for L 1 with IC50 = 12.83 μg/mL. This compound and the reference benomyl molecule also showed a correlation between experimental antifungal activity and theoretical predictions by Petra/Osiris/Molinspiration (POM) calculations and molecular coupling against the Fgb1 protein. The highest inhibition of bacterial growth for L 1 is due to its strongest binding to the target protein. This report may stimulate the further synthesis of examples of this substance class for the development of new drugs.

Garcia, Yann/0000-0002-3105-0735; karrouchi, khalid/0000-0002-8075-8051; Chkirate, Karim/0000-0002-9996-4963; RADI, Smaail/0000-0002-5062-6904; Sebbar, Nada Kheira/0000-0003-4944-1010 WOS: 000514598200055 Three mononuclear coordination complexes of 1-butyl-2-((5-methyl-1H-pyrazol-3-yl)methyl)-1H-benzimidazole (L), namely [CoL]Cl-2 (C1), [Co2L2]Cl-2 center dot H2O (C2) and [Zn2L2]Cl-2 (C3), have been synthesized and characterized spectroscopically. Their single-crystal X-ray diffraction analysis revealed that C1 and C2 display pseudopolymorphism. The presence of N-H center dot center dot center dot Cl and C-H center dot center dot center dot Cl hydrogen bonding in the crystal structure of C1 and C3 assists the formation of a 2D hydrogen bonded sheet and orthogonal packing [2D sheet + a pair of 1D chains], respectively, leading to supramolecular structures. A combination of N-H center dot center dot center dot Cl, C-H center dot center dot center dot Cl, O-H center dot center dot center dot Cl, and C-H center dot center dot center dot O interactions results however in a 2D corrugated hydrogen bonded sheet with inclusion of water molecules in C2. Hirshfeld surface analysis confirms that hydrogen bonding and pi-stacking contacts stabilize the crystal structures. These metal complexes display good performance towards their antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. In particular a normalized minimum inhibitory concentration as low as 6.25 mu g mL(-1) for the bacterial strains was recorded for C2. Its structure-bioactivity correlation is discussed in detail. bilateral WBI action with Morocco (COP 22 Program); Fonds De La Recherche Scientifique - FNRSFonds de la Recherche Scientifique - FNRS [PDR T.0102.15, CDR 33694457]; [PYOFEN.1906.19.001] This work was supported by a bilateral WBI action with Morocco (COP 22 Program 2018-2022), the Fonds De La Recherche Scientifique - FNRS (PDR T.0102.15, CDR 33694457) and project No. PYOFEN.1906.19.001.

The corrosion inhibition of mild steel in 1 M hydrochloric acid solution by some bipyrazole derivatives N,N'-dimethyl-N,N'-bis(1H-pyrazol-1-ylmethyl)ethane-1,2-diamine (3a), 1-{[{2-[[(3-carboxy-5-methyl-1H-pyrazol-1-yl)methyl](methyl)amino]ethyl}(methyl)amino]methyl}-5-methyl-1H-pyrazole-3-carboxylic acid (3b) and 1-{[{2-[{[3-(methoxycarbonyl)-1H-pyrazol-1-yl]methyl}(methyl)amino]ethyl}(methyl)amino]methyl}-1H-pyrazole-3-carboxylic acid (3c) has been studied in relation to the concentration of the inhibitors as well as the temperature using chemical (weight loss) and electrochemical (ac impedance and dc polarisation) techniques. All the methods employed are in reasonable agreement. The protection efficiency increases with increasing inhibitors concentration and with increasing temperature. The thermodynamic functions of dissolution and adsorption processes were calculated from weight loss measurement and the interpretation of the results are given. Adsorption of inhibitor on the carbon steel surface is found to obey the Langmuir adsorption isotherm.

Two mononuclear coordination complexes of N-(2-aminophenyl)-2-(5-methyl-1H-pyrazol-3-yl)acetamide (L1), namely [Cd(L1)2Cl2] (C1) and [Cu(L1)2(C2H5OH)2](NO3)2 (C2) and one mononuclear complex [Fe(L2)2(H2O)2](NO3)2·2H2O (C3), obtained after in situ oxidation of L1, have been synthesized and characterized spectroscopically. As revealed by single-crystal X-ray diffraction, each coordination sphere made of two heterocycles is completed either by two chloride anions (in C1), two ethanol molecules (in C2) or two water molecules (in C3). The crystal packing analysis of C1, C2 and C3, revealed 1D and 2D supramolecular architectures, respectively, via various hydrogen bonding interactions, which are discussed in detail. Furthermore, evaluation in vitro of the ligands and their metal complexes for their antibacterial activity against Escherichia coli (ATCC 4157), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 25923) and Streptococcus fasciens (ATCC 29212) strains of bacteria, revealed outstanding results compared to chloramphenicol, a well-known antibiotic, with a normalized minimum inhibitory concentration as low as 5 μg mL−1.

Herein we report the synthesis, DFT calculations, and molecular docking studies of a pyrazole derivative, (E)-N'-benzylidene-5-methyl-1H-pyrazole-3-carbohydrazide (E-BMPC) as α-glucosidase and α-amylase inhibitor. Molecular structure of E-BMPC has been confirmed by single crystal X-ray diffraction (XRD), FTIR, 1H, and 13C NMR spectra. In addition, density functional theory (DFT) calculations on E-BMPC were carried out to obtain frontier molecular orbital energies and first-order static hyperpolarizability (β). The α-amylase and α-glucosidase enzyme inhibitory of E-BMPC was also tested. E-BMPC displayed moderate inhibitory activity with IC50 values 310.57 ± 2.67 and 182.19 ± 3.20 against α-glucosidase and α-amylase enzymes, respectively. Molecular docking analysis provided the inhibition constant of E-BMPC molecule for α-amylase enzyme as 33.60 µM. Both in vitro and in silico enzyme inhibition studies showed that E-BMPC molecule is a better inhibitor for α-amylase than α-glucosidase. The β parameter for the molecule under investigation was also calculated as 4.2 × 10−30 esu.

BackgroundHuman and veterinary antibiotics are typically discharged as parent chemicals in urine or feces and are known to be released into the environment via wastewater treatment plants (WWTPs). Several research investigations have recently been conducted on the removal and bioremediation of pharmaceutical and personal care products (PPCPs) disposed in wastewater. ResultsSiNP-Cu, a chelating matrix, was produced by delaying and slowing 1.5-dimethyl-1H-pyrazole-3-carbaldehyde on silica gel from functionalized with 3-aminopropyltrimethoxysilane. The prepared sorbent material was characterized using several techniques including BET surface area, FT-IR spectroscopy, Scanning electron microscopy (SEM), Thermogravimetric analysis (TGA), and nitrogen adsorption-desorption isotherm. The pseudo-second-order model provided the best correlation due to the big match between the experimental and theoretical of different adsorption coefficients. The Langmuir and Freundlich adsorption models were used and the study showed better match with Fruendlich model. The removal capacity was depending on pH and increased by increasing pH The adsorbent demonstrated a high percentage removal of TMP, reaching more than 94 %. The sample was simply regenerated by soaking it for a few minutes in 1N HCl and drying it. The sorbent was repeated five times with no discernible decrease in removal capacity. Thermodynamic study also showed endothermic, increasing randomness and not spontaneous in nature. The findings of the DFT B3LYP/6-31+g (d,p) local reactivity descriptors revealed that nitrogen atoms and p-electrons of the benzene and pyrimidine rings in the TMP are responsible for the adsorption process with the SiNP surface. The negative values of the adsorption energies obtained by molecular dynamic simulation indicated the spontaneity of the adsorption process. ConclusionThe global reactivity indics prove that TMP is stable and it can be removed from wastewater using SiNP surface. The results of the local reactivity indices concluded that the active centers for the adsorption process are the nitrogen atoms and the p-electrons of the pyrimidine and benzene rings. Furthermore, the positive value of the maximum charge transfer number (DN) proves that TMP has a great tendency to donate electrons to SiNP surface during the process of adsorption.

The removal of heavy metals is attracting considerable attention due to their undesirable effects on the environment. In this investigation, a new adsorbent based on silica functionalized with pyridin-2-ylmethanol (SiPy) was successfully synthesized to yield to a hybrid material. FTIR, SEM, TGA, and specific surface area analysis were used to characterize the structure and morphology of the SiPy hybrid material. Various heavy metal ions such as Cu(ii), Zn(ii), Cd(ii), and Pb(ii) were selected to examine the adsorption efficiency of the newly prepared adsorbent, optimized at varying solution pH, contact time, concentration, and temperature. The adsorbent SiPy displayed good adsorption capacity of 90.25, 75.38, 55.23, and 35.12 mg g

Removal of heavy metals from drinking water sources and rivers is of strategic health importance and is essential for sustainable ecosystem development, in particular in polluted areas around the globe. In this work, new hybrid inorganic-organic material adsorbents made of ortho- (Si-o-OR) or para-Schiff base silica (Si-p-OR) were synthesized and characterized in depth. These hybrid adsorbents show a high selectivity to Cu(II), even in the presence of competing heavy metals (Zn(II), Cd(II), and Pb(II)), and also demonstrate great reusability after five adsorption-desorption cycles. Maximum sorption capacity for Cu(II) was found for Si-o-OR (79.36 mg g−1) and Si-p-OR (36.20 mg g−1) in no less than 25 min. Energy dispersive X-ray fluorescence and Fourier transform-infrared spectroscopy studies demonstrate that this uptake occurs due to a chelating effect, which allows these adsorbents to trap Cu(II) ions on their surfaces, this result is supported by a theoretical study for Si-o-OR. The new adsorbents were tested against real water samples extracted from two rivers from the Oriental region of Morocco.

Background: Pyrazole is an important class of heterocyclic compound, has been shown to exhibit diverse biological and pharmacological activities such as anti-inflammatory, anti-cancer, antioxidant, etc. Methods: In this study, a series of novel 3,5-dimethyl-1H-pyrazole derivatives containing hydrazine 4a-l have been synthesized via the reaction of the 2-(3,5-dimethyl-1H-pyrazol-1-yl)acetohydrazide. All synthesized compounds have been tested for their in vitro antioxidant activities via utilization of 1,1-biphenyl-2-picrylhydrazyl (DPPH) as a free radical scavenging reagent. Results: The data reported herein indicates that compound 4k showed potential radical scavenging capacity and compounds 4f and 4g exhibited best activity for the iron binding while comparing with positive controls. Conclusion: Good activity was noted for some compounds. In particular, compound 4k showed the highest antioxidant activity with IC50 values of 22.79 ± 3.64 and 1.35 ± 0.66 μg/mL in the DPPH and ABTS tests, respectively.

The pollution of water resources due to the disposal of toxic heavy metals has been a growing global concern for the last decades. For this purpose, the search for effective and economic material based adsorbents is required, due to the efficiency of the process. In this work, a novel inorganic-organic hybrid material based on silica chemically modified with a porphyrin (SiNTPP), with a high metal removal efficiency, was developed. The new material was characterized using a set of suitable techniques such as 13C NMR of the solid state, elemental analysis, FTIR, nitrogen adsorption-desorption isotherm, BET surface area, BJH pore sizes and scanning electron microscopy (SEM). The new material surface exhibits good chemical and thermal stability based on the obtained thermogravimetric curves (TGA). An adsorption study was accomplished to investigate the effect of porphyrin-silica hybrid on the removal of Pb(II), Zn(II), Cd(II) and Cu(II) from aqueous solutions using a batch method. The effect of various parameters, such as initial metal concentration, pH, temperature, as well as the kinetics and thermodynamics for sorption on SiNTPP were investigated. The studies demonstrate that adsorption is fast, as proved by the equilibrium achievement within 25min. The metals removal from aqueous solution are better adapted to the Langmuir isotherm model than to the Freundlich model. The thermodynamic parameters (ΔG°, ΔH° and ΔS°) disclose that the process was endothermic and spontaneous in nature, and the adsorption process follows a pseudo-second order kinetics. The adsorbent can be regenerated continuously without affecting its extraction percentage. Its effectiveness is highly justified compared to previous described materials.

© 2018 Elsevier B.V. The synthesis, spectroscopic characterization, reactivity study and evaluation of antioxidant and α-glucosidase inhibitory activities of two Schiff bases containing 1,2,4-triazole and pyrazole rings namely: 4-((4-methoxybenzylidene)amino)-5-(5-methyl-1H-pyrazol-3-yl)-4H-1,2,4-triazole-3-thiol 3a and 4-((4-(dimethylamino)benzylidene)amino)-5-(5-methyl-1H-pyrazol-3-yl)-4H-1,2,4-triazole-3-thiol 3b were reported in the present work. Reactive properties of the two compounds have been investigated by means of combination of DFT calculations, molecular dynamics (MD) simulations and drug likeness parameters, followed by calculations of molecular electrostatic potential (MEP) and average local ionization energy (ALIE) values. Additionally, the sensitivity of 3a and 3b towards the autoxidation mechanism has been investigated by the concept of bond dissociation energies for hydrogen abstraction (H-BDE). α-glucosidase inhibition assay revealed that the two compounds displayed significant inhibitory potentials in terms of relative IC50 values as compared to that of the reference drug (Acarbose). In addition, the antioxidant activity of the synthesized compounds were determined in vitro by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) and ferric reducing antioxidant power (FRAP) methods. Results revealed that the compound 3a is a potent antioxidant agent.

In the present study, two pyrazole-acetamide derivatives namely N‑(2‑aminophenyl)‑2‑(5‑methyl‑1H‑pyrazol‑3‑yl) acetamide (L1) and (E)‑N‑(2‑(1‑(2‑hydroxy‑6‑methyl‑4‑oxo‑4H‑pyran‑3‑yl)ethylideneamino)phenyl)‑2‑(5‑methyl‑1H‑pyrazol‑3‑yl) acetamide (L2) have been synthesized and characterized by infrared spectrophotometry (IR), nuclear magnetic resonance spectroscopy (NMR) and electrospray ionization-mass spectrometry (ESI-MS). Two coordination complexes of L1 and L2, namely [Co(L1)2(EtOH)2]·Cl2 (1) and [Cu(L2)]·H2O (2), respectively have been synthesized and characterized by elemental analysis and spectroscopic studies. The solid state structure of these two complexes was established by single crystal X-ray crystallography. In complex 1, the amide O and pyrazole N atoms of two molecules of L1 take part in coordination with octahedral Co(II) ions, the remaining two coordination sites being occupied by two EtOH molecules leading to a N2O4 coordination environment. On the other hand, the imine N atoms, pyrazole N and O atoms of the 2‑hydroxy‑6‑methyl‑4H‑pyran‑4‑one function present in L2 are involved in coordination with Cu(II) ions, resulting in a distorted square planar geometry displaying a N2O4 chromophore, in complex 2. The crystal packing analysis of 1 and 2, revealed 1D and 2D supramolecular architectures respectively, via various hydrogen bonding interactions, which are discussed in the present account. Furthermore, the antioxidant activity of the ligands and their complexes were determined in vitro by 1,1‑diphenyl‑2‑picrylhydrazyl (DPPH), 2,2′‑azino‑bis(3‑ethylbenzothiazoline‑6‑sulphonic acid (ABTS) and ferric reducing antioxidant power (FRAP), showing that the ligands L1 and L2 and complexes 1 and 2 present significant antioxidant activity.