scholarly journals The Nature of Interactions and UV-Induced Response within α-Zirconium Phosphate Intercalation Compounds with Azobenzenes

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1436 ◽  
Author(s):  
Anna Koteja ◽  
Jakub Matusik ◽  
Katarzyna Luberda-Durnaś ◽  
Marek Szczerba
Keyword(s):  
Molecular Modeling ◽  
Zirconium Phosphate ◽  
Interlayer Space ◽  
Hydrophobic Interactions ◽  
Functional Materials ◽  
Structural Features ◽  
Solid Support ◽  
Induced Response ◽  
Low Density ◽  
Experimental Approaches

Azobenzenes immobilization on a solid support enables the usage of their trans-cis isomerization ability for preparation of functional materials. The behavior of azobenzenes in the interlayer space of α-zirconium phosphate (ZrP) upon the UV–Vis irradiation was investigated. Two experimental approaches were performed: (1) co-intercalation of benzylalkylammonium surfactants and azobenzene in the interlayers of ZrP (ZBCnA), and (2) intercalation of p-aminoazobenzene (ZpA). The materials were characterized with XRD, FTIR, UV–Vis, CHN analysis, and the molecular modeling. The molecules in ZBCnA samples were sparsely packed and held by weak hydrophobic interactions. Conversely, the molecules in ZpA sample were strongly H-bonded to the ZrP, well-ordered, and densely packed. These structural features determined the samples’ photoresponsive behavior. Low density of molecules in the ZBCnA samples, allowed the effective, fast, and reversible isomerization of azobenzene. Whereas the ZpA sample did not react to the UV irradiation because of the steric hindrance of tightly packed molecules.

scholarly journals Crystallography, Molecular Modeling, and COX-2 Inhibition Studies on Indolizine Derivatives

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3550
Author(s):  
Katharigatta N. Venugopala ◽  
Sandeep Chandrashekharappa ◽  
Christophe Tratrat ◽  
Pran Kishore Deb ◽  
Rahul D. Nagdeve ◽  
...  
Keyword(s):  
Molecular Modeling ◽  
Graphical Representation ◽  
Hydrophobic Interactions ◽  
Basis Set ◽  
Monoclinic Crystal ◽  
X Ray ◽  
Cox Inhibitors ◽  
Design And Synthesis ◽  
Cox 2 ◽  
Cox 2 Inhibitors

The cyclooxygenase-2 (COX-2) enzyme is an important target for drug discovery and development of novel anti-inflammatory agents. Selective COX-2 inhibitors have the advantage of reduced side-effects, which result from COX-1 inhibition that is usually observed with nonselective COX inhibitors. In this study, the design and synthesis of a new series of 7-methoxy indolizines as bioisostere indomethacin analogues (5a–e) were carried out and evaluated for COX-2 enzyme inhibition. All the compounds showed activity in micromolar ranges, and the compound diethyl 3-(4-cyanobenzoyl)-7-methoxyindolizine-1,2-dicarboxylate (5a) emerged as a promising COX-2 inhibitor with an IC50 of 5.84 µM, as compared to indomethacin (IC50 = 6.84 µM). The molecular modeling study of indolizines indicated that hydrophobic interactions were the major contribution to COX-2 inhibition. The title compound diethyl 3-(4-bromobenzoyl)-7-methoxyindolizine-1,2-dicarboxylate (5c) was subjected for single-crystal X-ray studies, Hirshfeld surface analysis, and energy framework calculations. The X-ray diffraction analysis showed that the molecule (5c) crystallizes in the monoclinic crystal system with space group P 21/n with a = 12.0497(6)Å, b = 17.8324(10)Å, c = 19.6052(11)Å, α = 90.000°, β = 100.372(1)°, γ = 90.000°, and V = 4143.8(4)Å3. In addition, with the help of Crystal Explorer software program using the B3LYP/6-31G(d, p) basis set, the theoretical calculation of the interaction and graphical representation of energy value was measured in the form of the energy framework in terms of coulombic, dispersion, and total energy.

scholarly journals Three-Dimensional Structures of Carbohydrates and Where to Find Them

2020 ◽  
Vol 21 (20) ◽  
pp. 7702 ◽  
Author(s):  
Sofya I. Scherbinina ◽  
Philip V. Toukach
Keyword(s):  
Experimental Data ◽  
Molecular Modeling ◽  
Computational Methods ◽  
Three Dimensional ◽  
Structural Diversity ◽  
Structural Data ◽  
Structural Features ◽  
Data Validation ◽  
Data Generation ◽  
Efficient Treatment

Analysis and systematization of accumulated data on carbohydrate structural diversity is a subject of great interest for structural glycobiology. Despite being a challenging task, development of computational methods for efficient treatment and management of spatial (3D) structural features of carbohydrates breaks new ground in modern glycoscience. This review is dedicated to approaches of chemo- and glyco-informatics towards 3D structural data generation, deposition and processing in regard to carbohydrates and their derivatives. Databases, molecular modeling and experimental data validation services, and structure visualization facilities developed for last five years are reviewed.

Improving the Selectivity of the Luminescence Determination of Europium(III) with the Use of a Zirconium Phosphate Solid Support

2004 ◽  
Vol 59 (3) ◽  
pp. 246-249 ◽  
Author(s):  
S. B. Meshkova ◽  
Z. M. Topilova ◽  
N. A. Nazarenko ◽  
A. V. Litvinenko ◽  
N. P. Efryushina
Keyword(s):  
Zirconium Phosphate ◽  
Solid Support

scholarly journals Brown Seaweed Defensive Chemicals: A Structure-activity Relationship Approach for the Marine Environment

2009 ◽  
Vol 4 (2) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Éverson Miguel Bianco ◽  
Valéria Laneuville Teixeira ◽  
Renato Crespo Pereira ◽  
Alessandra Mendonça Teles de Souza ◽  
Pedro Nucci ◽  
...  
Keyword(s):  
Molecular Modeling ◽  
Pathogenic Bacteria ◽  
Brown Seaweed ◽  
Structure Activity Relationship ◽  
Structural Features ◽  
Activity Relationship ◽  
Chemical Structures ◽  
Structure Activity ◽  
Minimum Requirements ◽  
New Perspective

The literature describes several diterpenes from brown seaweeds that act as defensive chemicals against natural enemies, such as competitors, epiphytes, pathogenic bacteria and herbivores. A structure-activity relationship is here presented using a new molecular modeling approach to identify structural and chemical features important to the defensive profile of four structurally related diterpenes (three dolastanes and one seco-dolastane) from Canistrocarpus cervicornis against the feeding process of the omnivorous sea urchin Lytechinus variegatus. Our experimental data revealed the herbivory inhibitory profile (HIE) for three of these evaluated compounds with (4R, 7R, 14S)-4α, 7α-diacetoxy-14-hydroxydolast-1(15),8-diene presenting the highest effect (HIE = 70%). Interestingly, the molecular modeling results infer that this biological activity seems to be related to several different structural features, including HOMO distribution, the molecular structure conformation, and the fulfillment of minimum requirements regarding molecular weight. These results reinforce the hypothesis about the intricate biological mechanism of these molecules due to the complexity of their chemical structures. Our work may help in the understanding of these defensive mechanisms and point to a new perspective of ecological and/or evolutionary evaluation in this area.

scholarly journals Flame Retardant Polypropylene Composites with Low Densities

Materials ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 152 ◽  
Author(s):  
Nerea Pérez ◽  
Xiao-Lin Qi ◽  
Shibin Nie ◽  
Pablo Acuña ◽  
Ming-Jun Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Zirconium Phosphate ◽  
Synergetic Effect ◽  
Low Density ◽  
Material Density ◽  
Polypropylene Composites ◽  
Peak Heat Release Rate ◽  
Pp Composites

Polypropylene (PP) is currently widely used in areas requiring lightweight materials because of its low density. Due to the intrinsic flammability, the application of PP is restricted in many conditions. Aluminum trihydroxide (ATH) is reported as a practical flame retardant for PP, but the addition of ATH often diminishes the lightweight advantage of PP. Therefore, in this work, glass bubbles (GB) and octacedylamine-modified zirconium phosphate (mZrP) are introduced into the PP/ATH composite in order to lower the material density and simultaneously maintain/enhance the flame retardancy. A series of PP composites have been prepared to explore the formulation which can endow the composite with balanced flame retardancy, good mechanical properties, and low density. The morphology, thermal stability, flame retardancy, and mechanical properties of the composites were characterized. The results indicated the addition of GB could reduce the density, but decreased the flame retardancy of PP composites at the same time. To overcome this defect, ATH and mZrP with synergetic effect of flame retardancy were added into the composite. The dosage of each additive was optimized for achieving a balance of flame retardancy, good mechanical properties, and density. With 47 wt % ATH, 10 wt % GB, and 3 wt % mZrP, the peak heat release rate (pHRR) and total smoke production (TSP) of the composite PP-4 were reduced by 91% and 78%, respectively. At the same time, increased impact strength was achieved compared with neat PP and the composite with ATH only. Maintaining the flame retardancy and mechanical properties, the density of composite PP-4 (1.27 g·cm−3) is lower than that with ATH only (PP-1, 1.46 g·cm−3). Through this research, we hope to provide an efficient approach to designing flame retardant polypropylene (PP) composites with low density.

Identifying the structural features and diversifying the chemical domain of peripherally acting CB1 receptor antagonists using molecular modeling techniques

RSC Advances ◽  
2016 ◽  
Vol 6 (2) ◽  
pp. 1466-1483 ◽  
Author(s):  
Mayank Kumar Sharma ◽  
Prashant R. Murumkar ◽  
Guanglin Kuang ◽  
Yun Tang ◽  
Mange Ram Yadav
Keyword(s):  
Molecular Modeling ◽  
Virtual Screening ◽  
3D Qsar ◽  
Structural Features ◽  
Cb1 Receptor ◽  
Receptor Antagonists ◽  
Modeling Techniques ◽  
Qsar Models ◽  
Cb1 Receptor Antagonists

A four featured pharmacophore and predictive 3D-QSAR models were developed which were used for virtual screening of the Asinex database to get chemically diverse hits of peripherally active CB1 receptor antagonists.

Structural features of the low-density lipoprotein receptor facilitating ligand binding and release

2004 ◽  
Vol 32 (5) ◽  
pp. 721-723 ◽  
Author(s):  
N. Beglova ◽  
H. Jeon ◽  
C. Fisher ◽  
S.C. Blacklow
Keyword(s):  
Ligand Binding ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Structural Features ◽  
Low Ph ◽  
Low Density ◽  
Lipoprotein Receptor ◽  
Low Density Lipoprotein Receptor ◽  
Density Lipoprotein Receptor ◽  
Epidermal Growth

The LDLR (low-density lipoprotein receptor) is a modular protein built from several distinct structural units: LA (LDLR type-A), epidermal growth factor-like and β-propeller modules. The low pH X-ray structure of the LDLR revealed long-range intramolecular contacts between the propeller domain and the central LA repeats of the ligand-binding domain, suggesting that the receptor changes its overall shape from extended to closed, in response to pH. Here we discuss how the LDLR uses flexibility and rigidity of linkers between modules to facilitate ligand binding and low-pH ligand release.

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