scholarly journals Theoretical Investigation on Biological Activity of Imidazole Derivatives [Carbenzim, Mebendazole] by using (DFT) and (PM3) Methods

2021 ◽  
Vol 24 (2) ◽  
pp. 1-8
Author(s):  
Amar Tuma Musa ◽  
◽  
Khalida Abaid ◽  
Keyword(s):  
Density Functional ◽  
Chemical Potential ◽  
Theoretical Study ◽  
Chemical Reactivity ◽  
Biological Activities ◽  
Biological Properties ◽  
Benzimidazole Derivatives ◽  
Log P ◽  
P Value ◽  
Reactivity Descriptors

The theoretical study represents an essential preliminary stage for the start of any industry, as it gives a theoretical description of the properties of compounds (chemical, physical and biological properties)without conducting research to find out about this and the least cost. Through the theoretical study, we extract a clear picture of the chemical compounds before starting to manufacture them to know the extent of their impact on human health and their chemical and biological effectiveness. Using the Density Functional Theory (DFT/B3LYP) with base 6-311G,throughGaussian 09 program, the optimize geometry,(bond lengths, angles bond)and vibrational spectra was calculated of the benzimidazole derivatives [Carbenzim (CZM), Mebendazole (MBZ)].Through orbital charts of HOMO and LUMO to study electronic properties. The HOMO-LUMO gap was also evaluated for chemical reactivity and determination of global reactivity descriptors (Hardness (),Softness (S), Electrophilicity(), Chemical potential(),Electronegativity(χ))] that defines compunds effectiveness and the their biological activities. In addition, (QSAR) data has been used to develop relationships between biological activities and thermophysical properties of chemicals, through the Hyper Chem8.0programbyusingSemi-empirical(SE)method at the (PM3) level. The LOG P value was calculated, binding energy, Polarizability, hydration energy, surface area, and electrostatic potential energy difference of two level.

A comparative theoretical study on the biological activity, chemical reactivity, and coordination ability of dichloro-substituted (1,3-thiazol-2-yl)acetamides

2014 ◽  
Vol 92 (3) ◽  
pp. 234-239 ◽  
Author(s):  
Ambrish Kumar Srivastava ◽  
Neeraj Misra
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Chemical Reactivity ◽  
Biological Activities ◽  
First Principle ◽  
Reactivity Descriptors ◽  
Natural Bonding Orbital ◽  
Coordination Ability ◽  
Global Reactivity Descriptors ◽  
Orbital Analysis

We present a theoretical study on three dichloro-substituted (1,3-thiazol-2-yl)acetamides using the first principle density functional approach. Natural bonding orbital analysis is used to discuss the coordination ability of molecules and various global reactivity descriptors are calculated to compare their chemical reactivity. Biological activities of all three molecules are also evaluated. We find that the present molecules show potential coordination ability and their chemical reactivity varies with the position of substitution. We also notice that all three molecules show remarkable biological activities and the (3,4)-dichloro-substituted molecule is relatively more active. The study suggests further investigations on these molecules for their pharmacological importance.

Study of the Stability and Chemical Reactivity of a Series of Tetrazole Pyrimidine Hybrids by the Density Functional Theory Method (DFT)

2021 ◽  
Vol 37 (4) ◽  
pp. 805-812
Author(s):  
Ahissandonatien Ehouman ◽  
Adjoumanirodrigue Kouakou ◽  
Fatogoma Diarrassouba ◽  
Hakim Abdel Aziz Ouattara ◽  
Paulin Marius Niamien
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Molecular Descriptors ◽  
Chemical Reactivity ◽  
Density Functional Theory Method ◽  
Functional Theory ◽  
Reactivity Descriptors ◽  
The Density Functional Theory ◽  
The Stability ◽  
Global Reactivity Descriptors

Our theoretical study of stability and reactivity was carried out on six (06) molecules of a series of pyrimidine tetrazole hybrids (PTH) substituted with H, F, Cl, Br, OCH3 and CH3 atoms and groups of atoms using the density function theory (DFT). Analysis of the thermodynamic formation quantities confirmed the formation and existence of the series of molecules studied. Quantum chemical calculations at the B3LYP / 6-311G (d, p) level of theory determined molecular descriptors. Global reactivity descriptors were also determined and analyzed. Thus, the results showed that the compound PTH_1 is the most stable, and PTH_5 is the most reactive and nucleophilic. Similarly, the compound PTH_4 is the most electrophilic. The analysis of the local descriptors and the boundary molecular orbitals allowed us to identify the preferred atoms for electrophilic and nucleophilic attacks.

scholarly journals Synthesis, Characterization, Catalytic Activity, and DFT Calculations of Zn(II) Hydrazone Complexes

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4043 ◽  
Author(s):  
Temiloluwa T. Adejumo ◽  
Nikolaos V. Tzouras ◽  
Leandros P. Zorba ◽  
Dušanka Radanović ◽  
Andrej Pevec ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Gas Phase ◽  
Molecular Orbital ◽  
Density Functional ◽  
Chemical Potential ◽  
Chemical Reactivity ◽  
Geometry Optimization ◽  
Coupling Reaction ◽  
Functional Theory ◽  
Reactivity Descriptors

Two new Zn(II) complexes with tridentate hydrazone-based ligands (condensation products of 2-acetylthiazole) were synthesized and characterized by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy and single crystal X-ray diffraction methods. The complexes 1, 2 and recently synthesized [ZnL3(NCS)2] (L3 = (E)-N,N,N-trimethyl-2-oxo-2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)ethan-1-aminium) complex 3 were tested as potential catalysts for the ketone-amine-alkyne (KA2) coupling reaction. The gas-phase geometry optimization of newly synthesized and characterized Zn(II) complexes has been computed at the density functional theory (DFT)/B3LYP/6–31G level of theory, while the highest occupied molecular orbital and lowest unoccupied molecular orbital (HOMO and LUMO) energies were calculated within the time-dependent density functional theory (TD-DFT) at B3LYP/6-31G and B3LYP/6-311G(d,p) levels of theory. From the energies of frontier molecular orbitals (HOMO–LUMO), the reactivity descriptors, such as chemical potential (μ), hardness (η), softness (S), electronegativity (χ) and electrophilicity index (ω) have been calculated. The energetic behavior of the investigated compounds (1 and 2) has been examined in gas phase and solvent media using the polarizable continuum model. For comparison reasons, the same calculations have been performed for recently synthesized [ZnL3(NCS)2] complex 3. DFT results show that compound 1 has the smaller frontier orbital gap so, it is more polarizable and is associated with a higher chemical reactivity, low kinetic stability and is termed as soft molecule.

New molecular target insights about protein kinases of the Plasmodium falciparum. Using molecular docking and DFT-based reactivity descriptors

2017 ◽  
Vol 16 (08) ◽  
pp. 1750076 ◽  
Author(s):  
Alejandro Morales-Bayuelo
Keyword(s):  
Plasmodium Falciparum ◽  
Protein Kinases ◽  
Density Functional ◽  
Chemical Potential ◽  
Chemical Reactivity ◽  
Binding Pocket ◽  
Fukui Functions ◽  
Reactivity Descriptors ◽  
Chemical Reactivity Descriptors ◽  
Hinge Zone

Currently, there is increasing interest in the potential of malaria inhibitors in Plasmodium falciparum activity. In this work, is propose a possible alternative to classifying 154 antimalarials, with P. falciparum activity. These antimalarials were synthesized by the Chibale’s group ( http://www.kellychibaleresearch.uct.ac.za/ ), with the goal of finding new insights on the binding pocket of the protein kinase PfPK5, PfPK7, PfCDPK1, PfCDPK4, PfMAP1, and PfPK6 of the malaria parasite. However, there is only information about crystallography of PfPK5 and PfPK7. The protein kinases PfCDPK1, PfCDPK4, PfMAP1, and PfPK6 were modeled using molecular homology. The validation used shows that our homology models can be an alternative for the protein kinases from P. falciparum, unknown today. The antimalarials were classified by taking into account the interactions in the hinge zone. These ligands bind to the kinase through the formation of one of two hydrogen bonds, with the backbone residues of the hinge region connecting the kinase N- and C-terminal loops. These interactions were supported by a reactivity chemistry analysis, using global chemical reactivity descriptors such as chemical potential, hardness, softness, electrophilicity, and the Fukui functions as local reactivity descriptors, within the Density Functional Theory (DFT) context.

scholarly journals Topological Model on the Inductive Effect in Alkyl Halides Using Local Quantum Similarity and Reactivity Descriptors in the Density Functional Theory

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Alejandro Morales-Bayuelo ◽  
Ricardo Vivas-Reyes
Keyword(s):  
Density Functional ◽  
Chemical Potential ◽  
Inductive Effect ◽  
Chemical Reactivity ◽  
Topological Analysis ◽  
Basis Set ◽  
Organic Chemical ◽  
Quantum Similarity ◽  
Local Exchange ◽  
Reactivity Descriptors

We present a topological analysis to the inductive effect through steric and electrostatic scales of quantitative convergence. Using the molecular similarity field based in the local guantum similarity (LQS) with the Topo-Geometrical Superposition Algorithm (TGSA) alignment method and the chemical reactivity in the density function theory (DFT) context, all calculations were carried out with Amsterdam Density Functional (ADF) code, using the gradient generalized approximation (GGA) and local exchange correlations PW91, in order to characterize the electronic effect by atomic size in the halogens group using a standard Slater-type-orbital basis set. In addition, in this study we introduced news molecular bonding relationships in the inductive effect and the nature of the polar character in the C–H bond taking into account the global and local reactivity descriptors such as chemical potential, hardness, electrophilicity, and Fukui functions, respectively. These descriptors are used to find new alternative considerations on the inductive effect, unlike to the binding energy and dipole moment performed in the traditional organic chemical.

scholarly journals Therortical Studies and Investagting of Selected Potnet CDK2 Inhibitors as Anticancer Agents

2021 ◽  
Author(s):  
Mohammad J Abunuwar ◽  
Adnan A Dahadha
Keyword(s):  
Anticancer Agents ◽  
Density Functional ◽  
Chemical Potential ◽  
Chemical Reactivity ◽  
Three Dimensional ◽  
Data Bank ◽  
Basis Set ◽  
Chemical Hardness ◽  
Cyclin Dependent Kinase ◽  
Reactivity Descriptors

Abstract In this study eight selected of the most potent cyclin dependent kinase 2 inhibitors in which targeting adenosine triphosphate -pocket site theoretically investigated to support literature information of frontier molecular orbitals, molecular electrostatic maps, and global chemical reactivity descriptors such as chemical hardness, chemical softness, chemical potential, electronegativity and electrophilicity of cyclin dependent kinase 2 inhibitors. Calculation and three-dimensional plotting were achieved through Gaussian 09W and Gausview 6 software’s utilizing density functional theory quantum modeling applying both hybrids extended and not extended basis set. Crystal structure of CDK2 with inhibitors was obtained from protein data bank and visualized through PyMol Schrödinger software to assign polar and non-polar interactions of inhibitors with enzyme. A promising conclusion trend obtained in this research regarding to molecules that could have an inhibition activity toward the cyclin dependent kinase 2 enzymes. Our theoretical investigation emphasizes that, the anti-cancer activity has directly relationship with value of chemical hardness and chemical softness, where the most potent compounds was the pyrazolopyrimidine and imidazole pyrimidine and they have higher chemical hardness value and at the same time lower value of chemical softness compared with the rest of compounds.

A THEORETICAL STUDY OF DACTYLYNE STEREOISOMERS: A MARINE NATURAL PRODUCT FROM APLYSIA DACTYLOMELA

2012 ◽  
Vol 11 (04) ◽  
pp. 833-853 ◽  
Author(s):  
MARYAM FARROKHNIA ◽  
IRAJ NABIPOUR ◽  
AFSHAR BARGAHI
Keyword(s):  
Density Functional ◽  
Chemical Potential ◽  
Theoretical Study ◽  
Nbo Analysis ◽  
Marine Natural Product ◽  
Strong Electron ◽  
Reactivity Descriptors ◽  
Interaction Sites ◽  
Aplysia Dactylomela ◽  
The Persian Gulf

Dactylyne is an acetylenic dibromochloro ether from the Persian Gulf sea hare, Aplysia dactylomela. As a result of its unique structure and nontoxic nature; it has been known as a promising pharmacological substance of marine origin. A theoretical study of dactylyne and its stereoisomers, initiated in the hope of understanding more details of its action, is reported here. In the present research, for the first time, a density functional theory (DFT) calculation has been performed on the stereoisomers of dactylyne to determine the most stable configurations in gas phase. The HOMO–LUMO gap, global softness, chemical potential, and electrophilicity index have been calculated for the most stable stereoisomers at the B3LYP level of theory. These DFT-based global reactivity descriptors have been applied to demonstrate the reactive nature of compounds. Moreover, results from the quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) analysis have been employed to support the finding of more reactive stereoisomers. The investigation has indicated that the configuration of stereoisomers has some effects on their electronic and structural properties which control their global reactivity. It is also shown that the most probable interaction sites of dactylyne are in its unsaturated region. In the second part of our study, the effects of some typical substituents on dactylyne reactivity have been investigated theoretically and it has been shown that the strong electron donor groups increase the reactivity of dactylyne more than withdrawing substituent. However, creation of an ionic compound highly influences on reactivity descriptors.

scholarly journals DFT investigations on arylsulphonyl pyrazole derivatives as potential ligands of selected kinases

2020 ◽  
Vol 18 (1) ◽  
pp. 857-873
Author(s):  
Kornelia Czaja ◽  
Jacek Kujawski ◽  
Radosław Kujawski ◽  
Marek K. Bernard
Keyword(s):  
Free Energy ◽  
Molecular Orbital ◽  
Density Functional ◽  
Chemical Reactivity ◽  
Chemical Hardness ◽  
Free Energy Of Solvation ◽  
Fukui Functions ◽  
Reactivity Descriptors ◽  
Condensed Fukui Functions ◽  
Charge Partitioning

AbstractUsing the density functional theory (DFT) formalism, we have investigated the properties of some arylsulphonyl indazole derivatives that we studied previously for their biological activity and susceptibility to interactions of azoles. This study includes the following physicochemical properties of these derivatives: electronegativity and polarisability (Mulliken charges, adjusted charge partitioning, and iterative-adjusted charge partitioning approaches); free energy of solvation (solvation model based on density model and M062X functional); highest occupied molecular orbital (HOMO)–lowest occupied molecular orbital (LUMO) gap together with the corresponding condensed Fukui functions, time-dependent DFT along with the UV spectra simulations using B3LYP, CAM-B3LYP, MPW1PW91, and WB97XD functionals, as well as linear response polarisable continuum model; and estimation of global chemical reactivity descriptors, particularly the chemical hardness factor. The charges on pyrrolic and pyridinic nitrogen (the latter one in the quinolone ring of compound 8, as well as condensed Fukui functions) reveal a significant role of these atoms in potential interactions of azole ligand–protein binding pocket. The lowest negative value of free energy of solvation can be attributed to carbazole 6, whereas pyrazole 7 has the least negative value of this energy. Moreover, the HOMO–LUMO gap and chemical hardness show that carbazole 6 and indole 5 exist as soft molecules, while fused pyrazole 7 has hard character.

scholarly journals Theoretical Study of the Reaction of Formation of Some Free Phosphines by Stereoselective Hydrophosphination through DFT Method

2018 ◽  
pp. 1-10
Author(s):  
Kouadio Valery Bohoussou ◽  
Anoubilé Bénié ◽  
Mamadou Guy-Richard Koné ◽  
N’guessan Yao Silvère Diki ◽  
Kafoumba Bamba ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Chemical Reactivity ◽  
Dft Method ◽  
Trans Form ◽  
Dft Methods ◽  
Activation Barriers ◽  
Reactivity Descriptors ◽  
Chemical Reactivity Descriptors ◽  
Theoretical Results ◽  
Cis Isomer

In this work the formation of vinylphosphines was studied through the hydrophosphination reaction. The study aims to rationalize the stereoselectivity of these compounds using quantum DFT methods. This theoretical study of chemical reactivity was conducted at B3LYP/6-311 + G (d, p) level. Global chemical reactivity descriptors, stationary point energies and activation barriers were examined to foretell the relative stability of the stereoisomers formed. The various results obtained have revealed that the addition of arylphosphine to dihalogenoacetylene is stereospecific. The Trans form of vinylphosphines is more stable than the Cis form, when the substituent on phosphorus generates less or no π-conjugations. On the other hand, the Cis isomer is predominant when the aryl radical favors more π-conjugations. The theoretical results obtained are in agreement with the experimental results.

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