scholarly journals Reactivity of O-Drug Bond in some Suggested Voltarine Carriers: Semiempirical and ab Initio Methods

2021 ◽  
Vol 18 (4) ◽  
pp. 1249
Author(s):  
Rehab M. Kubba ◽  
Mustafa mohammed Kadhim
Keyword(s):  
Biological Activity ◽  
Quantum Mechanics ◽  
Geometrical Structure ◽  
Reaction Path ◽  
Bond Rupture ◽  
Ab Initio Methods ◽  
Calculation Methods ◽  
Nlo Properties ◽  
Total Energies ◽  
Optimized Geometries

In this work, the possibility to use new suggested carriers (D= Aspirin, Ibuprofen, Paracetamol, Tramal) is discussed for diclofenac drug (voltarine) by using quantum mechanics calculations. The calculation methods (PM3) and (DFT) have been used for determination the reaction path of (O-D) bond rupture energies. Different groups of drugs as a carrier for diclofenac prodrugs (in a vacuum) have been used; at their optimized geometries. The calculations included the geometrical structure and some of the physical properties, in addition to the toxicity, biological activity, and NLO properties of the prodrugs, investigated using HF method. The calculations were done by Gaussian 09 program. The comparison was made for total energies of reactants, activation energies, and transition states to final products. The suggested prodrugs aim to improve the diclofenac carrier's properties and obtain new alternatives for the approved carriers theoretically.

scholarly journals Quantum-Mechanical Assessment of the Energetics of Silver Decahedron Nanoparticles

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 767 ◽  
Author(s):  
Svatava Polsterová ◽  
Martin Friák ◽  
Monika Všianská ◽  
Mojmír Šob
Keyword(s):  
Ab Initio ◽  
Phenomenological Approach ◽  
Excess Energy ◽  
Quantum Mechanical ◽  
Ab Initio Methods ◽  
Surface Energies ◽  
Mechanical Study ◽  
Quantum Mechanical Study ◽  
Total Energies ◽  
Infinite Planar

We present a quantum-mechanical study of silver decahedral nanoclusters and nanoparticles containing from 1 to 181 atoms in their static atomic configurations corresponding to the minimum of the ab initio computed total energies. Our thermodynamic analysis compares T = 0 K excess energies (without any excitations) obtained from a phenomenological approach, which mostly uses bulk-related properties, with excess energies from ab initio calculations of actual nanoclusters/nanoparticles. The phenomenological thermodynamic modeling employs (i) the bulk reference energy, (ii) surface energies obtained for infinite planar (bulk-related) surfaces and (iii) the bulk atomic volume. We show that it can predict the excess energy (per atom) of nanoclusters/nanoparticles containing as few as 7 atoms with the error lower than 3%. The only information related to the nanoclusters/nanoparticles of interest, which enters the phenomenological modeling, is the number of atoms in the nanocluster/nanoparticle, the shape and the crystallographic orientation(s) of facets. The agreement between both approaches is conditioned by computing the bulk-related properties with the same computational parameters as in the case of the nanoclusters/nanoparticles but, importantly, the phenomenological approach is much less computationally demanding. Our work thus indicates that it is possible to substantially reduce computational demands when computing excess energies of nanoclusters and nanoparticles by ab initio methods.

scholarly journals Theoretical Study to Predict the Ability to Use Different Organic Substituents as Carrier Linkages for Diclofenac

2021 ◽  
Vol 33 (9) ◽  
pp. 2105-2118
Author(s):  
Rehab Majed Kubba ◽  
Aisha Muthana Shanshal
Keyword(s):  
Physical Properties ◽  
Theoretical Study ◽  
Reaction Path ◽  
Activation Energies ◽  
Quantum Mechanical ◽  
Quantum Mechanical Calculations ◽  
Geometrical Structures ◽  
Program Comparison ◽  
Total Energies ◽  
Sodium And Potassium

The research includes unrestricted (UDFT) and (UPM3) quantum mechanical calculations for studying the reaction path of bonds rupture energies of (O-R) and (C-OAr) in twelve diclofenac derivatives containing different substituted organic groups. All the calculations were performed at the optimize geometries in vacuum phase by using Gaussian 09 program. Comparison was done between the studied diclofenac derivatives and the standard ionic diclofenac of sodium and potassium included geometrical structures, physical properties, total energies of the reactants and products, activation energies and transition states. The results showed that some substituted organic groups could be used to form good carrier bonds for the acidic drug diclofenac, while others were less efficient depending on the nature of the substituted carrier, and that there is a preference for carriers of the type (–R) over the carriers of the type (–Ar).

Cluster Model Study to the As2-Adsorption on GaAs(001)-Surfaces

1996 ◽  
Vol 441 ◽  
Author(s):  
T. Marek ◽  
H. P. Strunk ◽  
S. Kunsági-Máté ◽  
N. Mareka
Keyword(s):  
Total Energy ◽  
Ab Initio ◽  
Cluster Model ◽  
Symmetry Axis ◽  
Reaction Path ◽  
Ab Initio Methods ◽  
Gaas Crystal ◽  
Reasonable Time ◽  
Model Study ◽  
Atomic Surface

AbstractWe study by using ab-initio methods the adsorption of As2-molecules on a Gaterminated GaAs(001) surface. We represent the GaAs crystal by a Ga5As2H8 cluster, which is large enough to resemble the crystal but sufficiently small to be tractable in a computer in a reasonable time. We calculate the reaction path along the symmetry axis C2 of this cluster and obtain the reaction path by minimizing the total energy of the system (cluster plus molecule). In the calculated positions above the cluster we account for the possibility of the As2-molecule to rotate around the C2 symmetry axis and for a change in the distance between the As-atoms. As a main result we obtain that for heights above the (001) surface less than about 3.5A we find a clear influence of the discrete atomic surface structure on the reaction path of the As2-molecule.

scholarly journals Complexes Between Adamantane Analogues B4X6 -X = {CH2, NH, O ; SiH2, PH, S} - and Dihydrogen, B4X6:nH2 (n = 1–4)

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1042 ◽  
Author(s):  
Josep M. Oliva-Enrich ◽  
Ibon Alkorta ◽  
José Elguero
Keyword(s):  
Perturbation Theory ◽  
Ab Initio ◽  
Boron Atom ◽  
Electrostatic Potentials ◽  
Binding Energies ◽  
The Other ◽  
Ab Initio Methods ◽  
Molecular Electrostatic Potentials ◽  
Optimized Geometries

In this work, we study the interactions between adamantane-like structures B4X6 with X = {CH2, NH, O ; SiH2, PH, S} and dihydrogen molecules above the Boron atom, with ab initio methods based on perturbation theory (MP2/aug-cc-pVDZ). Molecular electrostatic potentials (MESP) for optimized B4X6 systems, optimized geometries, and binding energies are reported for all B4X6:nH2 (n = 1–4) complexes. All B4X6:nH2 (n = 1–4) complexes show attractive patterns, with B4O6:nH2 systems showing remarkable behavior with larger binding energies and smaller B···H2 distances as compared to the other structures with different X.

scholarly journals Conformational Analysis, Substituent Effect and Structure Activity Relationships of 16-Membered Macrodiolides

2014 ◽  
Vol 33 ◽  
pp. 146-167 ◽  
Author(s):  
Radhia Mazri ◽  
Salah Belaidi ◽  
Aicha Kerassa ◽  
Touhami Lanez
Keyword(s):  
Biological Activity ◽  
Conformational Analysis ◽  
Electronic Structures ◽  
Substituent Effect ◽  
Dipole Moments ◽  
Ab Initio Methods ◽  
Electron Affinities ◽  
Structure Activity Relationships ◽  
Structure Activity ◽  
Net Charges

Electronic structures, Conformational Analysis, effect of the substitution and structure activity Relationships for macrodiolides, have been studied by PM3 and ab initio methods. In the present work, the calculated values, namely net charges, bond lengths, MESP, dipole moments, electron-affinities, heats of formation, drug-likeness and QSAR properties, are reported and discussed in terms of the biological activity of macrodiolides.

Virus-Like Particles in a Human Breast Cancer: Structural Similarity to Previously Reported Particles

1973 ◽  
Vol 31 ◽  
pp. 378-379
Author(s):  
G. Kasnic ◽  
S. E. Stewart ◽  
C. Urbanski
Keyword(s):  
Breast Cancer ◽  
Biological Activity ◽  
Human Breast Cancer ◽  
Osteogenic Sarcoma ◽  
Human Tumor ◽  
Structural Similarity ◽  
Cell Tumor ◽  
Human Breast ◽  
Human Tumor Cell ◽  
Type Particle

We have reported the maturation of an intracisternal A-type particle in murine plasma cell tumor cultures and three human tumor cell cultures (rhabdomyosarcoma, lung adenocarcinoma, and osteogenic sarcoma) after IUDR-DMSO activation. In all of these studies the A-type particle seems to develop into a form with an electron dense nucleoid, presumably mature, which is also intracisternal. A similar intracisternal A-type particle has been described in leukemic guinea pigs. Although no biological activity has yet been demonstrated for these particles, on morphologic grounds, and by the manner in which they develop within the cell, they may represent members of the same family of viruses.

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