Synthesis and Antioxidant Evaluation of Dihydropyrimidinone Integrated Pyrazoles

2019 ◽  
Vol 16 (12) ◽  
pp. 969-977
Author(s):  
Krishnaraj Padmavathy ◽  
Peramasivan Sutha ◽  
Kannan G. Krishnan ◽  
Chandran U. Kumar ◽  
Shunmugam Iniyaval ◽  
...  
Keyword(s):  
Density Functional ◽  
Radical Scavenging ◽  
Density Functional Theory Calculations ◽  
Basis Set ◽  
Spectral Techniques ◽  
Synthetic Strategy ◽  
B3lyp Method ◽  
Ic50 Value ◽  
Free Radical Scavenging Assay

: A series of novel ethyl 6-[2-(3-aryl-1-phenyl-1H-pyrazol-4-yl)vinyl]-2-oxo-4-phenyl- 1,2,3,4-tetrahydropyrimidine-5-carboxylates (9a-9d) has been synthesized by adopting a multistep synthetic strategy. The structure of the targets was confirmed on the basis of physical and spectral techniques. The synthetically achieved targets were evaluated for their antioxidant activity by in-vitro DPPH free radical scavenging assay. Of the chemical entities screened, most of them exhibit good to better radical scavenging profile and among those, the nitro substituent bearing molecule 9c displayed the highest activity (82%) with IC50 value 621.6 μM. Further, as a representative molecule, compound 9a has been subjected to density functional theory calculations employing B3LYP method with 6311(++G) basis set to optimize its structure.

scholarly journals Synthesis, characterization, in-vitro antimicrobial properties, molecular docking and DFT studies of 3-{(E)-[(4,6-dimethylpyrimidin-2-yl)imino]methyl} naphthalen-2-ol and Heteroleptic Mn(II), Co(II), Ni(II) and Zn(II) complexes

2018 ◽  
Vol 16 (1) ◽  
pp. 184-200 ◽  
Author(s):  
Festus Chioma ◽  
Anthony C. Ekennia ◽  
Aderoju A. Osowole ◽  
Sunday N. Okafor ◽  
Collins U. Ibeji ◽  
...  
Keyword(s):  
Schiff Base ◽  
Molecular Docking ◽  
Metal Complexes ◽  
Drug Targets ◽  
Density Functional ◽  
Radical Scavenging ◽  
Antimicrobial Properties ◽  
Density Functional Theory Calculations ◽  
Elemental Analyses

AbstractHeteroleptic divalent metal complexes [M(L) (bipy)(Y)]•nH2O (where M = Mn, Co, Ni, and Zn; L = Schiff base; bipy = 2,2’-bipyridine; Y = OAc and n = 0, 1) have been synthesized from pyrimidine Schiff base ligand 3-{(E)-[(4,6-dimethylpyrimidin-2-yl)imino]methyl} naphthalen-2-ol, 2,2’-bipyridine and metal(II) acetate salts. The Schiff base and its complexes were characterized by analytical (CHN elemental analyses, solubility, melting point, conductivity) measurements, spectral (IR, UV-vis, 1H and 13C-NMR and MS) and magnetometry. The elemental analyses, Uv-vis spectra and room temperature magnetic moment data provide evidence of six coordinated octahedral geometry for the complexes. The metal complexes’ low molar conductivity values in dimethylsulphoxide suggested that they were non-ionic in nature. The compounds displayed moderate to good antimicrobial and antifungal activities against S. aureus, P. aeruginosa, E. coli, B. cereus, P. mirabilis, K. oxytoca, A. niger, A. flevus and R. Stolonifer. The compounds also exhibited good antioxidant potentials with ferrous ion chelation and, 1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging assays. Molecular docking studies showed a good interaction with drug targets used. The structural and electronic properties of complexes were further confirmed by density functional theory calculations.

scholarly journals In Vitro and In Silico Antioxidant Activity of Novel Peptides Prepared from Paeonia Ostii ‘Feng Dan’ Hydrolysate

Antioxidants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 433 ◽  
Author(s):  
Min Wang ◽  
Cong Li ◽  
Haoyu Li ◽  
Zibo Wu ◽  
Bang Chen ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
In Silico ◽  
Density Functional ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Basis Set ◽  
Superior Performance ◽  
Antioxidant Peptides

Antioxidant peptides derived from natural products have superior performance and broader application prospects. In this study, five novel antioxidant peptides were prepared from Paeonia ostii (P. ostii) seed meal, moreover the bioactive and the relationship between structure and properties of antioxidant peptides were elucidated by quantum chemical calculations. The free radical-scavenging activities were used as indexes to purify and concentrate the antioxidant peptides through five proteases and separation techniques. FSAP (Phe-Ser-Ala-Pro), PVETVR (Pro-Val-Glu-Thr-Val-Arg), QEPLLR (Gln-Glu-Pro-Leu-Leu-Arg), EAAY (Glu-Ala-Ala-Tyr) and VLRPPLS (Val-Leu-Arg-Pro-Pro-Leu-Ser) were identified by nano liquid chromatography–tandem mass spectrometry (LC-MS/MS). In vitro antioxidant activity test, EAAY exhibited the highest 2, 2’-azino-bis (ABTS) and hydroxyl radical-scavenging activity of 98.5% ± 1.1% and 61.9% ± 1.3%, respectively (p < 0.01), at 0.5 mg/mL. In silico calculations were carried out using the density functional theory (DFT) with the B3LYP/6-31G* basis set. According to natural bond orbital (NBO) analysis, the bioactivity of free-radical scavenging of the peptides was presumed. Moreover, the antioxidant peptides demonstrated no obvious cytotoxicity to L929 fibroblast cells. Therefore, the peptides from P. ostii seed by-products might potentially have excellent uses in functional foods, nutraceuticals and pharmacological products.

scholarly journals In –vitro Antioxidant Activity of Methanolic Extract of the Roots of Bergenia ciliata

2018 ◽  
Vol 1 (4) ◽  
pp. 31-34
Author(s):  
Suman Lal Shrestha ◽  
Suresh Awale ◽  
Surya Kant Kalauni
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Methanolic Extract ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Ic50 Value ◽  
Free Radical Scavenging Assay ◽  
Radical Scavenging Assay ◽  
In Vitro Antioxidant Activity

Bergenia ciliata is an essential medicinal plant used in regions where western medicines are inaccessible due to their unavailability and high cost. The methanolic extract of Bergenia ciliataroots was separated for phytochemical elements and in-vitro antioxidant activity. The plant extract showed the rich outgrowth of secondary metabolites that play the role for biological activities. The higher antioxidant functioning of the plant is due to the occurrence of reactive elements like phenols and flavonoids. The antioxidant functioning of the plant extract was measured by DPPH free radical scavenging assay. In DPPH free radical scavenging assay the IC50 value of Bergenia ciliata was found to be 11.21μg/mL, while the IC50 value of standard ascorbic acid was found to be 45.93μg/mL

Quantum Mechanical Investigation of Geometrical Structure and Dynamic Behavior of h-BNNT (9,9-5) and h-AlNNT (9,9-5)Single-Walled Nanotubes: NBO Analysis

2019 ◽  
Vol 16 (9) ◽  
pp. 705-717
Author(s):  
Mehrnoosh Khaleghian ◽  
Fatemeh Azarakhshi
Keyword(s):  
Carbon Nanotubes ◽  
Density Functional ◽  
Structural Parameters ◽  
Energy Levels ◽  
Nbo Analysis ◽  
Electronic Energy ◽  
Boron Nitride Nanotubes ◽  
Basis Set ◽  
B3lyp Method ◽  
Mechanical Investigation

In the present research, B45H36N45 Born Nitride (9,9) nanotube (BNNT) and Al45H36N45 Aluminum nitride (9,9) nanotube (AlNNT) have been studied, both having the same length of 5 angstroms. The main reason for choosing boron nitride nanotubes is their interesting properties compared with carbon nanotubes. For example, resistance to oxidation at high temperatures, chemical and thermal stability higher rather than carbon nanotubes and conductivity in these nanotubes, unlike carbon nanotubes, does not depend on the type of nanotube chirality. The method used in this study is the density functional theory (DFT) at Becke3, Lee-Yang-Parr (B3LYP) method and 6-31G* basis set for all the calculations. At first, the samples were simulated and then the optimized structure was obtained using Gaussian 09 software. The structural parameters of each nanotube were determined in 5 layers. Frequency calculations in order to extract the thermodynamic parameters and natural bond orbital (NBO) calculations have been performed to evaluate the electron density and electrostatic environment of different layers, energy levels and related parameters, such as ionization energy and electronic energy, bond gap energy and the share of hybrid orbitals of different layers.

AlN Nanotubes: A DFT Study of Al-27 and N-14 Electric Field Gradient Tensors

2007 ◽  
Vol 62 (12) ◽  
pp. 711-715 ◽  
Author(s):  
Ahmad Seif ◽  
Mahmoud Mirzaei ◽  
Mehran Aghaie ◽  
Asadollah Boshra
Keyword(s):  
Electric Field ◽  
Electric Field Gradient ◽  
Field Gradient ◽  
Density Functional ◽  
Quadrupole Coupling Constant ◽  
Basis Set ◽  
Basis Sets ◽  
B3lyp Method ◽  
Package Program ◽  
Nqr Parameters

Density functional theory (DFT) calculations were performed to calculate the electric field gradient (EFG) tensors at the sites of aliminium (27Al) and nitrogen (14N) nuclei in an 1 nm of length (6,0) single-walled aliminium nitride nanotube (AlNNT) in three forms of the tubes, i. e. hydrogencapped, aliminium-terminated and nitrogen-terminated as representatives of zigzag AlNNTs. At first, each form was optimized at the level of the Becke3,Lee-Yang-Parr (B3LYP) method, 6-311G∗∗ basis set. After, the EFG tensors were calculated at the level of the B3LYP method, 6-311++G∗∗ and individual gauge for localized orbitals (IGLO-II and IGLO-III) types of basis sets in each of the three optimized forms and were converted to experimentally measurable nuclear quadrupole resonance (NQR) parameters, i. e. quadrupole coupling constant (qcc) and asymmetry parameter (ηQ). The evaluated NQR parameters revealed that the considered model of AlNNT can be divided into four equivalent layers with similar electrostatic properties.With the exception of Al-1, all of the three other Al layers have almost the same properties, however, N layers show significant differences in the magnitudes of the NQR parameters in the length of the nanotube. Furthermore, the evaluated NQR parameters of Al-1 in the Al-terminated form and N-1 in the N-terminated form revealed the different roles of Al (base agent) and of N (acid agent) in AlNNT. All the calculations were carried out using the GAUSSIAN 98 package program.

scholarly journals Synthesis and Antioxidant Properties of Novel 2-(2,4-Dioxothiazolidin-5-ylidene)-Acetamides Containing 1,3,4-Thia/Oxadiazole Moieties

2021 ◽  
Vol 12 (5) ◽  
pp. 6710-6722
Keyword(s):  
Ascorbic Acid ◽  
Acetyl Chloride ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Scavenging Effect ◽  
Highly Active ◽  
Ethanol Medium ◽  
Ic50 Value ◽  
Radical Scavenging Ability

A series of novel 1,3,4-thia(oxa)diazole substituted 2-(2,4-dioxothiazolidine-5-ylidene)-acetamides 3a-c, 4 and 5a-k have been synthesized following the acylation reaction of 2-amino-5-aryl-1,3,4-oxadiazoles, 5-amino-1,3,4-thiadiazole-2-thiol and it’s S-alkylated derivatives with 2-(2,4-dioxothiazolidine-5-ylidene)acetyl chloride in dioxane medium. The functionalization of compounds 3b, 3c, 5d and 5e was carried out on their N3 position under N-alkylation conditions with N-aryl-2-chloroacetamides in DMF/ethanol medium yielded the corresponding 2,4-dioxothiazolidine-3,5-diacetic acid diamides 6a-e and 7a-b. The structures of target compounds were confirmed by using 1H NMR spectroscopy and elemental analysis. The antioxidant activity evaluation in vitro of the synthesized compounds was performed by the method of scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. As a result, the highly active compound 4, namely 2-(2,4-dioxothiazolidin-5-ylidene)-N-(5-mercapto-[1,3,4]thiadiazol-2-yl)acetamide was found to be the most efficient candidate among all compounds with a radical scavenging ability of 88.9%, which was comparable that for ascorbic acid (92.7%). The experimentally calculated IC50 value of 43.1 µM for compound 4 was lower than for ascorbic acid (50.5 µM).

Synthesis, Molecular Modeling, DNA Damage Interaction, and Antioxidant Potential of Hesperidin Loaded on Gold Nanoparticles

2022 ◽  
Vol 54 ◽  
pp. 17-29
Author(s):  
Ghassan Mohammad Sulaiman ◽  
Hanaa M. Waheeba ◽  
Hanady AL-Shmgani ◽  
Hamsa A. Eassa ◽  
Ahmed A. Al-Amiery ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Density Functional ◽  
Radical Scavenging ◽  
Antioxidant Potential ◽  
Relationship Analysis ◽  
Dna Instability ◽  
Life Threatening ◽  
Antioxidant Agent ◽  
Bioactive Potential

The flavonoglycone hesperidin is recognized as a potent anti-inflammatory, anticancer, and antioxidant agent. However, its poor bioavailability is a crucial bottleneck regarding its therapeutic activity. Gold nanoparticles are widely used in drug delivery because of its unique properties that differ from bulk metal. Hesperidin loaded gold nanoparticles were successfully prepared to enhance its stability and bioactive potential, as well as to minimize the problems associated with its absorption. The free radical scavenging activities of hesperidin, gold nanoparticles, and hesperidin loaded gold nanoparticles were compared with that of Vitamin C and subsequently evaluated in vitro using 2,2-diphenyl-1-picrylhydrazyl assay. The antioxidant pharmacophore-based structure-activity relationship analysis was assessed by the density functional theory as well as quantum chemical calculations. Moreover, the structural properties were utilized using Becke’s three-parameter hybrid exchange and Lee-Yang-Parr’s correction of functional approaches. Hesperidin-loaded gold nanoparticles were found to decrease hydrogen peroxide (H2O2) and thus induce Deoxyribonucleic acid (DNA) instability. In addition, hesperidin-gold nanoparticles were observed to display important antioxidant potential as well as ameliorate the functional activity of macrophages against Escherichia coli, possibly protecting DNA. These particles might be appropriate for clinical trials and could prove useful for the treatment of various life-threatening disorders.

scholarly journals Experimental and Theoretical Studies of Novel Azo Benzene Functionalized Conjugated Polymers: In-vitro Antileishmanial Activity and Bioimaging

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Neetika Singh ◽  
Mohd. Arish ◽  
Prabhat Kumar ◽  
Abdur Rub ◽  
Ufana Riaz
Keyword(s):  
Atomic Orbital ◽  
Uv Spectra ◽  
Basis Set ◽  
Fluorescence Studies ◽  
H Nmr ◽  
Transmission Electron ◽  
B3lyp Method ◽  
Vis Spectroscopy ◽  
Experimental Findings

AbstractTo study the effect of insertion of azobenzene moiety on the spectral, morphological and fluorescence properties of conventional conducting polymers, the present work reports ultrasound-assisted polymerization of azobenzene with aniline, 1-naphthylamine, luminol and o-phenylenediamine. The chemical structure and polymerization was established via Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (1H-NMR) spectroscopy, while the electronic properties were explored via ultraviolet-visible (UV-vis) spectroscopy. Theoretical IR and UV spectra were computed using DFT/B3LYP method with 6–311G basis set while theoretical 1H-NMR spectra was obtained by gauge independent atomic orbital (GIAO) method. The theoretically computed spectra were found to be in close agreement with the experimental findings confirming the chemical as well as electronic structure of the synthesized polymers. Morphology was investigated by X-ray diffraction and transmission electron microscopy studies. Fluorescence studies revealed emission ranging between 530–570 nm. The polymers also revealed high singlet oxygen (1O2) generation characteristics. In-vitro antileishmanial efficacy as well as live cell imaging investigations reflected the potential application of these polymers in the treatment of leishmaniasis and its diagnosis.

scholarly journals Fatty Acids, Tocopherols, and Phytosterol Composition of Seed Oil and Phenolic Compounds and Antioxidant Activity of Fresh Seeds from Three Dalbergia Species Grown in Vietnam

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 542
Author(s):  
Thi Thuy Nguyen ◽  
Lan Phuong Doan ◽  
Thu Huong Trinh Thi ◽  
Hong Ha Tran ◽  
Quoc Long Pham ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Seed Oil ◽  
Radical Scavenging ◽  
Sterol Composition ◽  
Total Phenolic ◽  
Seed Oils ◽  
Free Radical Scavenging Assay ◽  
Phytosterol Composition

This research aimed to investigate the chemical composition of seed oils extracted from three Vietnamese Dalbergia species (D. tonkinensis, D. mammosa, and D. entadoides). The fatty acid profiles and contents of tocopherols and sterols of the seed oils, and total phenolic compounds extracted from the fresh seeds were characterized using different methods. Among the examined samples, D. tonkinensis seed oils showed high contents of linoleic acid (64.7%), whereas in D. mammosa, oleic acid (51.2%) was predominant. In addition, α- and γ-tocopherol and β-sitosterol were major ingredients in the seed oils, whereas ferulic acid and rosmarinic acid are usually predominant in the seeds of these species. Regarding sterol composition, the D. entadoides seed oil figured for remarkably high content of Δ5,23-stigmastadienol (1735 mg/kg) and Δ7-stigmastenol (1298 mg/kg). In addition, extracts with methanol/water (80:20, v/v) of seeds displayed significant in vitro antioxidant activity which was determined by DPPH free radical scavenging assay.

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