Structural analysis of an iron-assisted carbon monolayer for delivery of 2-thiouracil

2021 ◽  
pp. 1-9
Author(s):  
Azar Asgari Pari ◽  
Mohammad Yousefi ◽  
Susan Samadi ◽  
Mohammad Reza Allahgholi Ghasri ◽  
Maryam Bikhof Torbati
Keyword(s):  
Drug Delivery ◽  
Molecular Orbital ◽  
Density Functional ◽  
Dominant Role ◽  
Structural Features ◽  
Coupling Constants ◽  
Functional Theory ◽  
Quadrupole Coupling ◽  
Atomic Descriptors

An idea of employing an iron-assisted carbon (FeC) monolayer for delivery of 2-thiouracil (2TU) was examined in this work by analyzing structural features for singular and bimolecular models. Density functional theory (DFT) calculations were performed for optimizing the structures and evaluating molecular and atomic descriptors for analyzing the models systems. Two bimolecular models were obtained assigning by S-FeC and O-FeC models, in which each of S and O atom of 2TU was relaxed towards the Fe region of FeC surface in the mentioned models, respectively. The results indicated that both models were achievable with slightly more favorability for formation of S-FeC model. The obtained molecular orbital properties revealed the dominant role of FeC monolayer for managing future interactions of attached 2TU, which is indeed a major role for employing nanomaterials for targeted drug delivery purposes. In addition to energies and molecular orbital features, atomic quadrupole coupling constants indicated the benefit of employing FeC monolayer for drug delivery of 2TU.

Structural analysis of dexrazoxane: Exploring tautomeric conformations

2021 ◽  
pp. 1-8
Author(s):  
Farnoosh Behboodyzad ◽  
Tahereh Mohseniabbasabadi ◽  
Nahal Ghanemnia ◽  
Ebrahim Balali
Keyword(s):  
Structural Analysis ◽  
Density Functional ◽  
Distribution Patterns ◽  
Heterocyclic Ring ◽  
Coupling Constants ◽  
Original Structure ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Quadrupole Coupling

Structural analysis of dexrazoxane, as a cardioprotective agent, was done in this work by exploring formations of tautomeric conformations and investigating the corresponding effects. Density functional theory (DFT) calculations were performed to optimize the structures to evaluate their molecular and atomic descriptors. In addition to the original structure of dexrazoxane, eight tautomers were obtained with lower stability than the original compound. Movements of two hydrogen atoms in between nitrogen and oxygen atoms of heterocyclic ring put such significant effects. Moreover, electronic molecular orbital features showed effects of such tautomerism processes on distribution patterns and surfaces, in which evaluating the quadrupole coupling constants helped to show the role of atomic sites for resulting the features. As a consequence, the results indicated that the tautomeric formations could significantly change the features of dexrazoxane reminding the importance of carful medication of this drug for patients.

Investigating Functionalization Impacts on Structural Features of Barbituric Acid Derivatives: DFT Approach

2021 ◽  
pp. 1-9
Author(s):  
Narjes Hajali ◽  
Afshin Taghva Manesh ◽  
Ahmad Seif
Keyword(s):  
Density Functional ◽  
Barbituric Acid ◽  
Minimum Energy ◽  
Structural Features ◽  
Coupling Constants ◽  
Atomic Scale ◽  
Functional Theory ◽  
Quadrupole Coupling ◽  
Homo And Lumo ◽  
Characteristic Features

Density functional theory (DFT) calculations were performed to investigate electronic and structural properties of barbituric acid (BA) and sixtheen of its derivatives to show impacts of structural functionalization on the features of parent BA. The models were optimized and the minimum energy structures were confirmed by frequency calculations. Molecular and atomic descriptors were evaluated for the optimized models, in which the results of formation binding strength and molecular orbital features indicated significance of such functionalization processes on the observed properties. The highest occupied and the lowest unoccupied molecular orbitals (HOMO and LUMO) and their related parameters all indicated magnitudes of changes from one molecule to another one. Furthermore, atomic scale quadrupole coupling constants (Cq) were evaluated for the nitrogen and oxygen atoms of BA compounds showing significance of structural functionalization impacts on the atomic properties of parent BA. As a consequence, such structural analyses of BA compounds could show their characteristic features for further developments especially for their efficient pharmaceutical applications.

Iron Chelation by thiocytosine: Investigating electronic and structural features for describing tautomerism and metal chelation processes

2021 ◽  
pp. 1-8
Author(s):  
Azadeh Jafari Rad ◽  
Maryam Abbasi ◽  
Bahareh Zohrevand
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Molecular Orbital ◽  
Density Functional ◽  
Biological Systems ◽  
Iron Chelation ◽  
Structural Features ◽  
Metal Chelation ◽  
Functional Theory

This work was performed regarding the importance of iron (Fe) chelation for biological systems. This goal was investigated by assistance of a model of thiocytosine (TC) for participating in Fe-chelation processes. First, formations of tautomeric conformations were investigated to explore existence of possible structures of TC. Next, Fe-chelation processes were examined for all four obtained tautomers of TC. The results indicated that thiol tautomers could be seen at higher stability than thio tautomers, in which one of such thiol tautomers yielded the strongest Fe-chelation process to build FeTC3 model. As a consequence, parallel to the results of original TC tautomers, Fe-chelated models were found to be achievable for meaningful chelation processes or sensing the existence of Fe in media. Examining molecular orbital features could help for sensing purposes. The results of this work were obtained by performing density functional theory (DFT) calculations proposing TC compounds suitable for Fe-chelation purposes.

Density Functional Theory Studies of Bonding in Complexes H3N···XY of Ammonia and Dihalogen Molecules: A Comparison with Experimental Results from Rotational Spectroscopy

2002 ◽  
Vol 57 (6-7) ◽  
pp. 537-543 ◽  
Author(s):  
O. Kh. Poleshchuk ◽  
A. C. Legona
Keyword(s):  
Density Functional ◽  
Natural Bond Orbital ◽  
Coupling Constants ◽  
Rotational Spectroscopy ◽  
Charge Redistribution ◽  
Functional Theory ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Experimental Values

The electron density and nuclear quadrupole coupling constants (NQCC) of the H3N...XY (n a type in Mulliken notation) complexes, (X, Y = F, Cl, Br and I), are analyzed with the aid of density functional calculations. To demonstrate the quality of the calculations, various bond lengths and NQCCs obtained by using the hybrid Becke-Lee-Perdew-Yang functional are compared with the corresponding experimental values determined from rotational spectroscopy. An analysis of the NQCC values and various quantities derived fromthe natural bond orbital approach reveals that the molecular interaction is mainly electrostatic, with probably only a small extent of intermolecular electric charge redistribution on complex formation

A boroxol ring doped zigzag boron nitride nanotube: a computational DFT study of the quadrupole coupling constant

2009 ◽  
Vol 87 (6) ◽  
pp. 647-652 ◽  
Author(s):  
Asadollah Boshra ◽  
Ahmad Seif
Keyword(s):  
Density Functional Theory ◽  
Boron Nitride ◽  
Density Functional ◽  
Quadrupole Coupling Constant ◽  
Coupling Constants ◽  
Boron Nitride Nanotube ◽  
Coupling Constant ◽  
Functional Theory ◽  
Quadrupole Coupling ◽  
Dopant Atoms

Based upon density functional theory, we investigate the influence of oxygen dopant atoms that make a boroxol ring on the electrostatic properties of a zigzag (10, 0) boron nitride nanotube in which three of the nitrogen atoms are replaced by oxygen dopant atoms. The electric field gradient (EFG) tensors at the sites of 11B and 14N nuclei were calculated and converted to quadrupole coupling constants (CQ) in the two models of a perfect and a boroxol ring O-doped (10, 0) single-walled boron nitride nanotube (BNNT). Our calculations showed that the CQ values of the boron and nitrogen nuclei along the length of a perfect BNNT are divided into layers. Among the layers the mouth layers have the largest CQ magnitudes. In the doped model, in addition to the mouth layers, the CQ values of those nitrogen nuclei which directly bond to the boroxol ring are increased. However, the CQ values of the boron nuclei that make the boroxol ring and directly bond to the boroxol ring are decreased.

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