Métodos compostos adaptados ao método ONIOM foram utilizados no cálculo teórico de afinidades por próton (PA) e eletrônica (EA) para um grupo de 50 moléculas (álcoois, cetonas, radicais e alcenos). A energia eletrônica foi descrita considerando-se o escalonamento de ZPE (λ) e a correção de alto nível (HLC). O valor ótimo para λ foi obtido através dos dados de PA. Os cálculos de EA foram utiliza...

In this article, we theoretically analyze the Diels-Alder cycloaddition between cyclopentadiene and C60 for which experimental results on energy barriers and reaction energies are known. The comparison of the results obtained with the two-layered ONIOM approach using different partitions for the high- and low-level layers with those obtained employing the B3LYP/6-31G(d) method for the entire sy...

As the first application of our recently developed ONIOM2(QM:MM) and ONIOM3(QM:QM:MM) codes to the metalloenzymes with a large number of protein residues, two members of the non-heme protein family, methane monooxygenause and ribonucleotide reductase, have been chosen. The "active-site + four alpha-helical fragments" model was adopted which includes about 1000 atoms from 62 residues around the ...

Theoretical investigations of the interaction between dapivirine and the HIV-1 RT binding site have been performed by the ONIOM2 (B3LYP/6-31G (d,p): PM3) and B3LYP/6-31G (d,p) methods. The results derived from this study indicate that this inhibitor dapivirine forms two hydrogen bonds with Lys101 and exhibits strong π-π stacking or H…π interaction with Tyr181 and Tyr188. These interactions play...

to improve drug selectivity toward target cells, one interesting approach for drug delivery is to use polymer nanoparticles. a two-layered oniom becke3- lyp: uff calculation was carried out to study the structural and thermodynamic properties of the interaction between acetamide derivatives and the pca-peg-pca copolymers. the interaction enthalpies and the gibbs free energies between acetamide ...

Objective(s): The novel 7-hydroxycoumarinyl gallates derivatives are detected in many pharmaceutical compounds like anticancer and antimicrobial agents. Whereas carbon nanotubes (CNTs) have been discussed for nanomedicine applications and in particular as drug delivery systems. The capability of armchair (5, 5) SWCNT -based drug delivery system in the therapy of anticancer has been investigated...

objective(s): the novel 7-hydroxycoumarinyl gallates derivatives are detected in many pharmaceutical compounds like anticancer and antimicrobial agents. whereas carbon nanotubes (cnts) have been discussed for nanomedicine applications and in particular as drug delivery systems. the capability of armchair (5, 5) swcnt -based drug delivery system in the therapy of anticancer has been investigated...

Quantum chemistry calculations were done, using the ONIOM2 methodology at two different levels of calculation, B3LYP for the high level and UFF for the low level. These calculations were performed on Au3/SAPO-11, Au4/SAPO-11, CO-Au3/SAPO-11 and CO-Au4/SAPO-11 aggregates to analyze the geometries of small clusters of Au3 and Au4 on SAPO-11 support. Au3 cluster present a triangle structure in Au3...

In this study, the thermodynamic and reactivity characteristics of coumarin-derived ligand inclusion complexes with βCD were described, in addition to situ these ligands their changes complex cavity. For purpose, computational tools such as molecular docking, second order perturbative analysis (E2PERT), ONIOM2 (DFT/PM6) methods employed obtain global local indices, parameters, non-covalent int...

Linear–dendrite copolymers containing hyper branched poly(citric acid) and linear poly(ethylene glycol) blocks PCA–PEG–PCA are promising nonmaterial to use  in nanomedicine. To investigate their potential application in biological systems (especially for drug carries) ONIOM2 calculations were applied to study the nature of particular interactions between drug and the polymeric nanoparticle...