scholarly journals Possibility of Complexation of the Calix[4]Arene Molecule with the Polluting Gases: DFT and NCI-RDG Theory

2020 ◽  
Author(s):  
Bouzid Gassoumi ◽  
Fatma Ezzahra Ben Mohamed ◽  
Houcine Ghalla ◽  
Rafik Ben Chaabane
Keyword(s):  
Drug Delivery ◽  
Binding Energies ◽  
Basis Set ◽  
Gaseous Pollutants ◽  
Sensitive Area ◽  
Basis Set Superposition Error ◽  
Pharmaceutical Drug ◽  
Pollution Problem ◽  
Non Covalent Interactions ◽  
Covalent Interactions

The calix[4]arenes (abbreviated as CX[4]) are characterized by a specific hydrophobic cavity formed by a four cyclically phenol groups to encapsulate a gas or small molecules. Recently, the CX[4] molecule is used in a specific media and in pharmaceutical drug delivery. The pollution problem will be a vital subject in the future because the increase of the explosions of the gaseous pollutants in the environment. In this report, we have encapsulated the polluting gases NO3, NO2, CO2 and N2 by the calix[4]arene molecule. In this work, The binding energies of the CX[4]-gas has been calculated including the BSSE (Basis Set Superposition Error) counterpoise (CP). The red-shift of the O-H bonding interactions obtained by adding the gas in the sensitive area of calix[4]arene is clearly explained by the infrared spectrum analysis. The Molecular electrostatic potential (MEP) of the stable CX[4]-gas complexes have been investigated in the endo-vs. exo-cavity regions. Finally, the non-covalent interactions analyses of the stable host-guests complexes have been estimated by using DFT calculations.

scholarly journals On the Use of Popular Basis Sets: Impact of the Intramolecular Basis Set Superposition Error

Molecules ◽  
2019 ◽  
Vol 24 (20) ◽  
pp. 3810 ◽  
Author(s):  
Ángel Vidal Vidal ◽  
Luis de Vicente Poutás ◽  
Olalla Nieto Faza ◽  
Carlos Silva López
Keyword(s):  
Small Molecules ◽  
Chemical Properties ◽  
Basis Set ◽  
Basis Sets ◽  
Basis Set Superposition Error ◽  
Large Molecules ◽  
Molecular Complexation ◽  
Non Covalent Interactions ◽  
Covalent Interactions ◽  
Structure Calculations

The magnitude of intramolecular basis set superposition error (BSSE) is revealed via computing systematic trends in molecular properties. This type of error is largely neglected in the study of the chemical properties of small molecules and it has historically been analyzed just in the study of large molecules and processes dominated by non-covalent interactions (typically dimerization or molecular complexation and recognition events). In this work we try to provide proof of the broader prevalence of this error, which permeates all types of electronic structure calculations, particularly when employing insufficiently large basis sets.

Delineating synchronized control of dynamic covalent and non-covalent interactions for polymer chain collapse towards cargo localization and delivery

2021 ◽  
Author(s):  
Jojo P Joseph ◽  
Chirag Miglani ◽  
Aashish Bhatt ◽  
Debes Ray ◽  
Ashmeet Singh ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Polymer Chain ◽  
Structural Control ◽  
Synthetic Polymers ◽  
Folding Process ◽  
Non Covalent Interactions ◽  
Covalent Interactions ◽  
Synchronized Control

Chain collapse in synthetic polymers is an excellent approach to mimick natural self-folding process that imparts structural control leading to attractive compartmental applications e.g. drug delivery. In this regard, water...

scholarly journals The S66 Non-Covalent Interactions Benchmark Reconsidered Using Explicitly Correlated Methods Near the Basis Set Limit

2018 ◽  
Vol 71 (4) ◽  
pp. 238 ◽  
Author(s):  
Manoj K. Kesharwani ◽  
Amir Karton ◽  
Nitai Sylvetsky ◽  
Jan M. L. Martin
Keyword(s):  
Computational Cost ◽  
The Other ◽  
Basis Set ◽  
Basis Sets ◽  
Explicitly Correlated ◽  
Non Covalent Interactions ◽  
Explicitly Correlated Methods ◽  
The One ◽  
High Level ◽  
Covalent Interactions

The S66 benchmark for non-covalent interactions has been re-evaluated using explicitly correlated methods with basis sets near the one-particle basis set limit. It is found that post-MP2 ‘high-level corrections’ are treated adequately well using a combination of CCSD(F12*) with (aug-)cc-pVTZ-F12 basis sets on the one hand, and (T) extrapolated from conventional CCSD(T)/heavy-aug-cc-pV{D,T}Z on the other hand. Implications for earlier benchmarks on the larger S66×8 problem set in particular, and for accurate calculations on non-covalent interactions in general, are discussed. At a slight cost in accuracy, (T) can be considerably accelerated by using sano-V{D,T}Z+ basis sets, whereas half-counterpoise CCSD(F12*)(T)/cc-pVDZ-F12 offers the best compromise between accuracy and computational cost.

scholarly journals Chitosan-Based Biocompatible Copolymers for Thermoresponsive Drug Delivery Systems: On the Development of a Standardization System

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1876
Author(s):  
Lorenzo Marsili ◽  
Michele Dal Bo ◽  
Federico Berti ◽  
Giuseppe Toffoli
Keyword(s):  
Drug Delivery ◽  
Biomedical Applications ◽  
Biological Tissues ◽  
Special Focus ◽  
Thermoresponsive Polymers ◽  
Basic Principles ◽  
Natural Polysaccharide ◽  
Non Covalent Interactions ◽  
Covalent Interactions ◽  
Or Applications

Chitosan is a natural polysaccharide that is considered to be biocompatible, biodegradable and non-toxic. The polymer has been used in drug delivery applications for its positive charge, which allows for adhesion with and recognition of biological tissues via non-covalent interactions. In recent times, chitosan has been used for the preparation of graft copolymers with thermoresponsive polymers such as poly-N-vinylcaprolactam (PNVCL) and poly-N-isopropylamide (PNIPAM), allowing the combination of the biodegradability of the natural polymer with the ability to respond to changes in temperature. Due to the growing interest in the utilization of thermoresponsive polymers in the biological context, it is necessary to increase the knowledge of the key principles of thermoresponsivity in order to obtain comparable results between different studies or applications. In the present review, we provide an overview of the basic principles of thermoresponsivity, as well as a description of the main polysaccharides and thermoresponsive materials, with a special focus on chitosan and poly-N-Vinyl caprolactam (PNVCL) and their biomedical applications.

9. pH Triggered Molecular Tweezers for Drug Delivery Applications

2016 ◽  
Author(s):  
Caitlin Miron
Keyword(s):  
Drug Delivery ◽  
Targeted Delivery ◽  
Chemical Potential ◽  
Cancer Drug ◽  
Molecular Tweezers ◽  
Binding Domains ◽  
Non Covalent Interactions ◽  
Molecular Tweezer ◽  
First Time ◽  
Covalent Interactions

Molecular tweezers are simple synthetic receptors that are generally composed of two binding domains connected by a spacer group. The non-covalent interactions that occur between the tweezer and its substrate are usually reversible, which facilitates the release of the bound substrate at a target site when triggered by a stimulus such as light, temperature, pH,] or change in chemical potential. In the field of cancer research, one strategy for targeting drug delivery relies on the pH drop in cancerous tissues compared to healthy tissues. We recently showed, for the first time, that it is possible to use pH to tune the binding affinity of molecular tweezers for substrates such as the cancer drug MitoxantroneTM. The molecular tweezer switches conformation from a closed (binding) state to an open (release) state upon acidification. As a result, the targeted delivery of MitoxantroneTM is achieved. This proof of concept shows that molecular tweezers are promising tools for selective drug delivery.

Performance of small basis set Hartree–Fock methods for modeling non-covalent interactions

2021 ◽  
Vol 3 (3) ◽  
pp. 034007
Author(s):  
Viki Kumar Prasad ◽  
Alberto Otero-de-la-Roza ◽  
Gino A DiLabio
Keyword(s):  
Basis Set ◽  
Hartree Fock ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Binding Energies of Organic Charge-Transfer Complexes Calculated by First-Principles Methods

1998 ◽  
Vol 63 (8) ◽  
pp. 1223-1244 ◽  
Author(s):  
Cordula Rauwolf ◽  
Achim Mehlhorn ◽  
Jürgen Fabian
Keyword(s):  
Density Functional Theory ◽  
Charge Transfer ◽  
Ground State ◽  
Density Functional ◽  
Binding Energies ◽  
Basis Set ◽  
Dispersion Energy ◽  
Functional Theory ◽  
Basis Set Superposition Error ◽  
Donor And Acceptor

Weak interactions between organic donor and acceptor molecules resulting in cofacially-stacked aggregates ("CT complexes") were studied by second-order many-body perturbation theory (MP2) and by gradient-corrected hybrid Hartree-Fock/density functional theory (B3LYP exchange-correlation functional). The complexes consist of tetrathiafulvalene (TTF) and related compounds and tetracyanoethylene (TCNE). Density functional theory (DFT) and MP2 molecular equilibrium geometries of the component structures are calculated by means of 6-31G*, 6-31G*(0.25), 6-31++G**, 6-31++G(3df,2p) and 6-311G** basis sets. Reliable molecular geometries are obtained for the donor and acceptor compounds considered. The geometries of the compounds were kept frozen in optimizing aggregate structures with respect to the intermolecular distance. The basis set superposition error (BSSE) was considered (counterpoise correction). According to the DFT and MP2 calculations laterally-displaced stacks are more stable than vertical stacks. The charge transfer from the donor to the acceptor is small in the ground state of the isolated complexes. The cp-corrected binding energies of TTF/TCNE amount to -1.7 and -6.3 kcal/mol at the DFT(B3LYP) and MP2(frozen) level of theory, respectively (6-31G* basis set). Larger binding energies were obtained by Hobza's 6-31G*(0.25) basis set. The larger MP2 binding energies suggest that the dispersion energy is underestimated or not considered by the B3LYP functional. The energy increases when S in TTF/TCNE is replaced by O or NH but decreases with substitution by Se. The charge-transferred complexes in the triplet state are favored in the vertical arrangement. Self-consistent-reaction-field (SCRF) calculations predicted a gain in binding energy with solvation for the ground-state complex. The ground-state charge transfer between the components is increased up to 0.8 e in polar solvents.

scholarly journals Dendrimers as drug delivery vehicles: non-covalent interactions of bioactive compounds with dendrimers

2007 ◽  
Vol 56 (4) ◽  
pp. 489-496 ◽  
Author(s):  
Hannah L Crampton ◽  
Eric E Simanek
Keyword(s):  
Drug Delivery ◽  
Bioactive Compounds ◽  
Drug Delivery Vehicles ◽  
Delivery Vehicles ◽  
Non Covalent Interactions ◽  
Covalent Interactions

scholarly journals Columnar Aggregates of Azobenzene Stars: Exploring Intermolecular Interactions, Structure, and Stability in Atomistic Simulations

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7598
Author(s):  
Markus Koch ◽  
Marina Saphiannikova ◽  
Olga Guskova
Keyword(s):  
Hydrogen Bonds ◽  
Md Simulations ◽  
Binding Energies ◽  
Atomistic Simulations ◽  
Π Interactions ◽  
Different Types ◽  
Non Covalent Interactions ◽  
Experimental Works ◽  
Supramolecular Aggregates ◽  
Covalent Interactions

We present a simulation study of supramolecular aggregates formed by three-arm azobenzene (Azo) stars with a benzene-1,3,5-tricarboxamide (BTA) core in water. Previous experimental works by other research groups demonstrate that such Azo stars assemble into needle-like structures with light-responsive properties. Disregarding the response to light, we intend to characterize the equilibrium state of this system on the molecular scale. In particular, we aim to develop a thorough understanding of the binding mechanism between the molecules and analyze the structural properties of columnar stacks of Azo stars. Our study employs fully atomistic molecular dynamics (MD) simulations to model pre-assembled aggregates with various sizes and arrangements in water. In our detailed approach, we decompose the binding energies of the aggregates into the contributions due to the different types of non-covalent interactions and the contributions of the functional groups in the Azo stars. Initially, we investigate the origin and strength of the non-covalent interactions within a stacked dimer. Based on these findings, three arrangements of longer columnar stacks are prepared and equilibrated. We confirm that the binding energies of the stacks are mainly composed of π–π interactions between the conjugated parts of the molecules and hydrogen bonds formed between the stacked BTA cores. Our study quantifies the strength of these interactions and shows that the π–π interactions, especially between the Azo moieties, dominate the binding energies. We clarify that hydrogen bonds, which are predominant in BTA stacks, have only secondary energetic contributions in stacks of Azo stars but remain necessary stabilizers. Both types of interactions, π–π stacking and H-bonds, are required to maintain the columnar arrangement of the aggregates.

Advances in oral controlled drug delivery: the role of drug–polymer and interpolymer non-covalent interactions

2014 ◽  
Vol 12 (3) ◽  
pp. 441-453 ◽  
Author(s):  
Simona De Robertis ◽  
Maria Cristina Bonferoni ◽  
Lisa Elviri ◽  
Giuseppina Sandri ◽  
Carla Caramella ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Controlled Drug Delivery ◽  
Non Covalent Interactions ◽  
Covalent Interactions
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