Search

In this research, the geometric structure of LTZ and CCT (5,0) was optimized with B3LYP/6-31G* method using the Gaussian 09W program package to investigate the weak interaction of Letrozole (LTZ) and carbon carbon nanotube (CCT). According to the calculation of the release energy, it was found that the drug delivery process is desirable. Also, the structural properties of the title compounds were assessed by thermodynamic and frontier molecular orbital (FMO) parameters. In this study, a series of measures have been performed to detect changes in drug loading properties and non-bonding interactions between the LTZ and CCT (5,0) nanotube. The non-bonding interaction effects of LTZ and CCT over the electronic properties were also evaluated and argued. The research is based on the fact that studies can help to understand the interaction between the LTZ drug and CCT (5,0) nanotube and the development of CCT-based drug release systems. This research aimed to determine variations in electronic properties of anticancer LTZ drug in presences CCT. Then, the reactivity and stability behavior of LTZ drug and on CCT to be examined by density functional theory (DFT). Then, frontier molecular orbital (FMO) and noncovalent interaction (NCI) analyses were performed, which decrease in reactivity described increase in the stability of LTZ drug. [ABSTRACT FROM AUTHOR]

Electronic and structural features of some of representative chromene derivatives were investigated in this work towards recognizing their anticancer roles. Density functional theory (DFT) calculations were performed to obtain five structures of chromene derivatives with the same skeleton of original structure. In addition to obtaining optimized structural geometries, electronic molecular orbital features were evaluated for the models. Energy levels of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) indicated effects of additional R group pf chromene derivatives on electronic features. Based on such results, it was predicted that one of derivatives, L5, could better participate in interactions with other substances in comparison with other ligand structures. This achievement was obtained based on availability of HOMO and LUMO levels in lower energies easily catchable for electron transferring. On the other hand, L5 was assumed to interact in the weakest mode with other substances. Indeed, the main goal of this work was to examine anticancer activity of the investigated chromene derivatives, in which each of L1–L5 chromene derivatives were analyzed first to recognized electronic and structural features. Next, molecular docking (MD) simulations were performed to examine anticancer role of L1–L5 against methyltransferase cancerous enzyme target. The results indicated that formations of ligand-target complexes could be occurred within different types of interactions and surrounding amino acids of central ligand. In agreement with the achievements of analyses of single-standing L1–L5 compounds, L4-Target was seen as the strongest complex among possible complex formations. Moreover, values of binding energies and inhibition constant indicated that all five chromene derivatives could work as inhibitors of methyltransferase cancerous enzyme by the most advantage for L4 ligand. And as a final remark, details of such anticancer activity were recognized by graphical representations of ligand-target complexes showing types of interactions and involving amino acids in interactions. [ABSTRACT FROM AUTHOR]

Photosensitization analyses of models of (–HC = CH–)n assisted coronene-cytosine complexes assigned by Cor-n-Cyt; n varying by 0, 1, 2, and 3, were investigated in this work by performing density functional theory (DFT) calculations. The investigated models were optimized and chemical descriptors were evaluated. To achieve the goal of this work, energy levels of the highest occupied and the lowest unoccupied molecular orbitals (HOMO and LUMO) were evaluated to reach the absorption energy requirement for innovating photosensitizer (PS) compounds. The models indicated that the complex formations could help the structures to participate in interactions easier than the singular models, in which HOMO-LUMO descriptors indicated lower required absorption energy for them to increase their safety for human health level. The required absorption energies of complexes with n = 0, 1, and 2, were in ultraviolet (UV) region whereas that of complex with n = 3 was moved to visible region. In this regard, the idea of new PS compounds innovation was examined here to introduce Cor-n-Cyt complexes for possible applications in photodynamic therapy (PDT). [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]