Comparative analysis of interactions between the hydropyridine dicarboxylate derivatives and different proteins by molecular docking and charge density analysis

2016 ◽  
Vol 15 (06) ◽  
pp. 1650050
Author(s):  
Yanjiao Qi ◽  
Yaming Zhao ◽  
Xiaoe Wang ◽  
Huining Lu ◽  
Nengzhi Jin
Keyword(s):  
Molecular Docking ◽  
Charge Density ◽  
Molecular Orbital ◽  
Drug Target ◽  
Active Sites ◽  
Drug Transport ◽  
Transport Protein ◽  
Target Protein ◽  
Frontier Molecular Orbital ◽  
Density Analysis

Molecular docking and charge density analysis were carried out to understand the geometry, charge density distribution and electrostatic properties of one of newly synthesized 4-substituted-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylates (PDE), which is regarded as the best [Formula: see text]-Glucosidase inhibitor among the hydropyridine dicarboxylate derivatives. The different bonding models of the PDE molecule in the active sites of proteins Human serum albumin (HSA) and Saccharomyces cerevisiae [Formula: see text]-glucosidase (SAG) are firstly compared, which is important to understand the different intermolecular interactions between drug-transport protein and drug-target protein. The deformation density maps suggest that the electron densities of the PDE molecule are redistributed when it presents in the active sites. When the molecule presents in the active site of the SAG, it is evident to find that the negative region does not appear at the vicinity of the oxygen atoms on one of the carboxylic acid dimethyl ester group. Frontier molecular orbital density distributions for the PDE molecule are similar in all forms. The highest occupied molecular orbital (HOMO) and lowest occupied molecular orbital (LUMO) energy gaps in the active sites are higher than that of the molecule in pure solution phase. It is generally noticed that all of the orientations of the dipole moment vectors are reoriented in both active sites. These fine details at electronic level allow to better understand the exact drug-transport protein and drug-target protein interactions.

scholarly journals Supramolecular Stark Effect in Host-Guest Complexes via Charge Density Analysis

2014 ◽  
Vol 70 (a1) ◽  
pp. C674-C674
Author(s):  
Sajesh Thomas ◽  
Rebecca Fuller ◽  
Alexandre Sobolev ◽  
Philip Schauer ◽  
Simon Grabowsky ◽  
...  
Keyword(s):  
Electric Field ◽  
Charge Density ◽  
Electric Fields ◽  
Active Sites ◽  
Stark Effect ◽  
Dipole Moments ◽  
Covalent Bonds ◽  
Guest Molecules ◽  
Density Mapping ◽  
Density Analysis

The effect of an electric field on the vibrational spectra, the Vibrational Stark Effect (VSE), has been utilized extensively to probe the local electric field in the active sites of enzymes [1, 2]. For this reason, the electric field and consequent polarization effects induced by a supramolecular host system upon its guest molecules attain special interest due to the implications for various biological processes. Although the host-guest chemistry of crown ether complexes and clathrates is of fundamental importance in supramolecular chemistry, many of these multicomponent systems have yet to be explored in detail using modern techniques [3]. In this direction, the electrostatic features associated with the host-guest interactions in the inclusion complexes of halogenated acetonitriles and formamide with 18-crown-6 host molecules have been analyzed in terms of their experimental charge density distribution. The charge density models provide estimates of the molecular dipole moment enhancements which correlate with the simulated values of dipole moments under electric field. The accurate electron density mapping using the multipole formalism also enable the estimation of the electric field experienced by the guest molecules. The electric field vectors thus obtained were utilized to estimate the vibrational stark effect in the nitrile (-C≡N) and carbonyl (C=O) stretching frequencies of the guest molecules via quantum chemical calculations in gas phase. The results of these calculations indicate remarkable elongation of C≡N and C=O bonds due to the electric fields. The electronic polarization in these covalent bonds induced by the field manifests as notable red shifts in their characteristic vibrational frequencies. These results derived from the charge densities are further supported by FT-IR experiments and thus establish the significance of a phenomenon that could be termed as the "supramolecular Stark effect" in crystal environment.

scholarly journals Conformational Flexibility and the Interaction of Huperzine A in the Active Site of Acetylcholinesterase: A Quantum Chemical and Charge Density Study

2016 ◽  
Author(s):  
Renuga Parameswari Azhagesan ◽  
Saravanan Kandasamy ◽  
Kumaradhas Poomani
Keyword(s):  
Molecular Docking ◽  
Density Distribution ◽  
Charge Density ◽  
Gas Phase ◽  
Active Site ◽  
Quantum Chemical ◽  
Conformational Flexibility ◽  
Huperzine A ◽  
Charge Density Distribution ◽  
Density Analysis

Huperzine A is an herbal reversible inhibitor of Acetylcholinesterase (AChE). A molecular docking analysis on Huperzine A molecule has been carried out to understand its structure, conformational flexibility, intermolecular interaction and the binding affinity in the active site of AChE enzyme. Further, the charge density distribution of huperzine A molecule (lifted from the active site of AChE) was determined from the high level quantum chemical calculations coupled with charge density analysis. The binding affinity of Huperzine A towards AChE was calculated from the molecular docking; the lowest docked energy is -8.46 kcal/mol. In the active site, huperzine A molecule interacts with acyl binding pocket-Phe330 of AChE, that is, the bicyclo ring group of huperzine A forms an intermolecular interaction with the oxygen atom of main chain of the amino acid residue Phe330 at the distances 3.02 and 3.25 Å respectively. On the other hand, a gas phase study on huperzine A molecule also performed using HF and DFT (B3LYP) methods with the basis set 6-311G**. The molecular structure, conformation, and the charge density distribution of huperzine A molecule in the gas phase have determined using quantum chemical calculations and the charge density analysis. The comparative studies between the gas phase and the active site forms of huperzine A molecule, explicitly reveals the degree of conformational modification and the charge density redistribution of huperzine A when present in the active site. The dipole moment of the molecule in the active site is 6.85 D, which is slightly higher than its gas phase value (5.91 D). The electrostatic potential (ESP) surface of active site molecule clearly shows the strong electronegative and positive ESP regions of the molecule, which are the expected strong reactive locations of the molecule.

scholarly journals Synthesis, Single Crystal X-Ray Structure, Hirshfeld Surface Analysis, DFT Computations, Docking Studies on Aurora Kinases and an Anticancer Property of 3-(2,3-Dihydrobenzo[b][1,4]dioxin-6-yl)-6-methoxy-4H-chromen-4-one

Crystals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 413 ◽  
Author(s):  
Seunghyun Ahn ◽  
Jiha Sung ◽  
Ji Hye Lee ◽  
Miri Yoo ◽  
Yoongho Lim ◽  
...  
Keyword(s):  
Molecular Orbital ◽  
Surface Analysis ◽  
Active Sites ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
Frontier Molecular Orbital ◽  
Monoclinic Space Group ◽  
Term Survival ◽  
X Ray ◽  
Anti Cancer

The isoflavone compound 3-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-6-methoxy-4H-chromen-4-one (6) was prepared and structurally characterized using NMR, mass spectrum and X-ray crystallography. Compound 6, C18H14O5, was crystallized in the monoclinic space group P21/n with the cell parameters; a = 7.1869(4) Å, b = 10.2764(6) Å, c = 19.6771(10) Å, β = 99.442(2)°, V = 1433.57(14) Å3, Z = 4. In the title compound, the chromenone ring system is slightly twisted from planarity and the dihedral angle formed between the plane of the chromenone ring and benzene ring is 47.75°. Several intermolecular hydrogen bonds make the crystal stabilized in the three-dimensional structure, which was confirmed by Hirshfeld surface analysis. Density functional theory (DFT) calculations at the B3LYP/6-311++G(d,p) level were carried out and the calculated geometric parameters were compared with the experimental results. A frontier molecular orbital calculation was performed to reveal that the energy values of highest occupied molecular orbital (HOMO) and lowest un-occupied molecular orbital (LUMO) were −5.8223 eV and −1.8447 eV, and the HOMO–LUMO energy gap was 3.9783 eV. A clonogenic long-term survival assay of compound 6 against HCT116 human colon cancer cells showed an anti-cancer ability, with GI50 value of 24.9 μM. Docking experiments within the active sites of aurora kinase A and B were carried out to explain the anti-cancer property of compound 6.

scholarly journals De-novo Drug Design, Molecular Docking and In-Silico Molecular Prediction of AChEI Analogues through CADD Approaches as Anti-Alzheimer’s Agents

2020 ◽  
Vol 16 (1) ◽  
pp. 54-72 ◽  
Author(s):  
Surabhi Pandey ◽  
B.K. Singh
Keyword(s):  
Molecular Docking ◽  
Drug Design ◽  
Inhibitory Activity ◽  
In Silico ◽  
Active Sites ◽  
De Novo ◽  
Docking Studies ◽  
Target Protein ◽  
Design And Development ◽  
Reference Drug

Background: There are over 44 million persons who suffer with Alzheimer’s disease (AD) worldwide, no existence of cure and only symptomatic treatments are available for it. The aim of this study is to evaluate the anti-Alzheimer potential of designed AChEI analogues using computer simulation docking studies. AChEIs are the most potential standards for treatment of AD, because they have proven efficacy. Among all AChEIs donepezil possesses lowest adverse effects, it can treat mildmoderate- severe AD and only once-daily dosing is required. Therefore, donepezil is recognized as a significant prototype for design and development of new drug molecule. Methods: In this study the Inhibitory potential of the design compounds on acetylcholinesterase enzyme has been evaluated. Docking studies has been performed which further analyzed by in-silico pharmacokinetic evaluation through pharmacopredicta after that Interaction modes with enzyme active sites were determined. Docking studies revealed that there is a strong interaction between the active sites of AChE enzyme and analyzed compounds. Results: As a result 26 compounds have been indicates better inhibitory activity on AChE enzyme and all the screening parameters have also been satisfied by all 26 compounds. From these 26 compounds, six compounds 17, 18, 24, 30, 36 and 56 are found to be the most potent inhibitors of this series by insilico study through INVENTUS v 1.1 software, having highest bio-affinities i.e. - 8.51, - 7.67, - 8.30, - 7.59, - 8.71 and -7.62 kcal/mol respectively, while the standard or reference drug donepezil had binding affinity of - 6.32 kcal/mol. Conclusion: Computer aided drug design approach has been playing an important role in the design and development of novel anti- AD drugs. With the help of structure based drug design some novel analogues of donepezil have been designed and the molecular docking studies with structure based ADME properties prediction studies is performed for prediction of AChE inhibitory activity. The binding mode of proposed compounds with target protein i.e. AChE has been evaluated and the resulting data from docking studies explains that all of the newly designed analogues had significantly high affinity towards target protein compared to donepezil as a reference ligand.

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