scholarly journals Computation-guided asymmetric total syntheses of resveratrol dimers

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Masaya Nakajima ◽  
Yusuke Adachi ◽  
Tetsuhiro Nemoto
Keyword(s):  
Natural Products ◽  
Organic Synthesis ◽  
Density Functional ◽  
Computational Simulation ◽  
Chemical Research ◽  
Asymmetric Total Synthesis ◽  
Functional Theory ◽  
Total Syntheses ◽  
Simulation Based ◽  
Computational Predictions

AbstractAlthough computational simulation-based natural product syntheses are in their initial stages of development, this concept can potentially become an indispensable resource in the field of organic synthesis. Herein we report the asymmetric total syntheses of several resveratrol dimers based on a comprehensive computational simulation of their biosynthetic pathways. Density functional theory (DFT) calculations suggested inconsistencies in the biosynthesis of vaticahainol A and B that predicted the requirement of structural corrections of these natural products. According to the computational predictions, total syntheses were examined and the correct structures of vaticahainol A and B were confirmed. The established synthetic route was applied to the asymmetric total synthesis of (−)-malibatol A, (−)-vaticahainol B, (+)-vaticahainol A, (+)-vaticahainol C, and (−)-albiraminol B, which provided new insight into the biosynthetic pathway of resveratrol dimers. This study demonstrated that computation-guided organic synthesis can be a powerful strategy to advance the chemical research of natural products.

scholarly journals Defect Properties and Lithium Incorporation in Li2ZrO3

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3963
Author(s):  
Kobiny Antony Rex ◽  
Poobalasuntharam Iyngaran ◽  
Navaratnarajah Kuganathan ◽  
Alexander Chroneos
Keyword(s):  
Atomistic Simulation ◽  
Density Functional ◽  
Functional Theory ◽  
Lithium Zirconate ◽  
Simulation Based ◽  
Electrochemical Devices ◽  
Li Ion ◽  
Cluster Energy ◽  
Experimental Values ◽  
Lithium Incorporation

Lithium zirconate is a candidate material in the design of electrochemical devices and tritium breeding blankets. Here we employ an atomistic simulation based on the classical pair-wise potentials to examine the defect energetics, diffusion of Li-ions, and solution of dopants. The Li-Frenkel is the lowest defect energy process. The Li-Zr anti-site defect cluster energy is slightly higher than the Li-Frenkel. The Li-ion diffuses along the c axis with an activation energy of 0.55 eV agreeing with experimental values. The most favorable isovalent dopants on the Li and Zr sites were Na and Ti respectively. The formation of additional Li in this material can be processed by doping of Ga on the Zr site. Incorporation of Li was studied using density functional theory simulation. Li incorporation is exoergic with respect to isolated gas phase Li. Furthermore, the semiconducting nature of LZO turns metallic upon Li incorporation.

scholarly journals Molecular Modeling-Guided Design of Phospholipid-Based Prodrugs

2019 ◽  
Vol 20 (9) ◽  
pp. 2210 ◽  
Author(s):  
Milica Markovic ◽  
Shimon Ben-Shabat ◽  
Shahar Keinan ◽  
Aaron Aponick ◽  
Ellen M. Zimmermann ◽  
...  
Keyword(s):  
Molecular Modeling ◽  
Density Functional ◽  
Molecular Design ◽  
Computational Simulation ◽  
Functional Theory ◽  
Brain Barrier Permeability ◽  
Processing Pathways ◽  
Triggered Drug Release ◽  
Energy Perturbation ◽  
Dynamics Simulations

The lipidic prodrug approach is an emerging field for improving a number of biopharmaceutical and drug delivery aspects. Owing to their structure and nature, phospholipid (PL)-based prodrugs may join endogenous lipid processing pathways, and hence significantly improve the pharmacokinetics and/or bioavailability of the drug. Additional advantages of this approach include drug targeting by enzyme-triggered drug release, blood–brain barrier permeability, lymphatic targeting, overcoming drug resistance, or enabling appropriate formulation. The PL-prodrug design includes various structural modalities-different conjugation strategies and/or the use of linkers between the PL and the drug moiety, which considerably influence the prodrug characteristics and the consequent effects. In this article, we describe how molecular modeling can guide the structural design of PL-based prodrugs. Computational simulations can predict the extent of phospholipase A2 (PLA2)-mediated activation, and facilitate prodrug development. Several computational methods have been used to facilitate the design of the pro-drugs, which will be reviewed here, including molecular docking, the free energy perturbation method, molecular dynamics simulations, and free density functional theory. Altogether, the studies described in this article indicate that computational simulation-guided PL-based prodrug molecular design correlates well with the experimental results, allowing for more mechanistic and less empirical development. In the future, the use of molecular modeling techniques to predict the activity of PL-prodrugs should be used earlier in the development process.

scholarly journals Copper (IV) Stabilization in Macrocyclic Complexes with 3,7,11,15-Tetraazaporphine, Its Di[benzo]- or Tetra[benzo] Derivatives and Oxide Anion: Quantum-Chemical Research

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3162 ◽  
Author(s):  
Oleg V. Mikhailov ◽  
Denis V. Chachkov
Keyword(s):  
Quantum Chemical ◽  
Density Functional ◽  
Nbo Analysis ◽  
Macrocyclic Complexes ◽  
Molecular Structures ◽  
Chemical Research ◽  
Functional Theory ◽  
Chemical Modeling ◽  
The Density Functional Theory ◽  
Oxidation State Of Copper

Using the data of a quantum chemical modeling of molecular structures obtained by the density functional theory (DFT), the possibility of the existence of a copper macrocyclic complexes with 3,7,11,15-tetraazaaporphine, trans-di[benzo] 3,7,11,15-tetraazaaporphine or tetra[benzo] 3,7,11,15-tetraazaaporphine and oxide anion where oxidation state of copper is IV, was shown. The values of the parameters of molecular structures and NBO analysis for such complexes were presented, too.

Gas-phase reaction of ClO− with CHnCl4-n (n = 0, 1, 2, 3) and CX3H (X = F, Cl and Br): Substituent effect from a comparative study

2014 ◽  
Vol 92 (9) ◽  
pp. 868-875 ◽  
Author(s):  
Liang Junxi ◽  
Su Qiong ◽  
Li Yu ◽  
Zhang Qiang ◽  
Geng Zhiyuan
Keyword(s):  
Density Functional ◽  
Substituent Effects ◽  
Bond Distance ◽  
State Theory ◽  
Basis Set ◽  
Phase Reaction ◽  
Chemical Research ◽  
Functional Theory ◽  
Deprotonation Reaction ◽  
Strain Model

Substituent effects on reactivity are studied using the hybrid B3LYP and BHandHLYP methods of density functional theory with the aug-cc-pVDZ basis set. The chosen testing models includes two very representative reactions in chemical research, the bimolecular nucleophilic substitution (SN2) reaction and the deprotonation reaction, in which the former is represented by ClO− + CHnCl4-n (n = 0, 1, 2, 3), and the latter is based on reactions of ClO− with CX3H (X = F, Cl, and Br). Our theoretical findings suggest that a heavier substituent X in substrate results in a higher activation energy, a slower SN2 reaction, but a faster deprotonation reaction. Those are well confirmed by some presented results from bond orders, second-order perturbative energy E(2), and activation strain model analysis. Moreover, we have further explored the reactivity difference derived from substituent effects in term of the relationships of reactive barrier with the charges transferred and the leaving-bond distance in TSs, respectively, especially the TSs in SN2 reactions. Again, the rate constants at 298–1000 K are also evaluated for the SN2 reactions presented through the transition state theory.

Molecular Bilateral Symmetry of Natural Products:  Prediction of Selectivity of Dimeric Molecules by Density Functional Theory and Semiempirical Calculations

2004 ◽  
Vol 67 (7) ◽  
pp. 1141-1146 ◽  
Author(s):  
Tatyana Voloshchuk ◽  
Nicola S. Farina ◽  
Orrette R. Wauchope ◽  
Magdalena Kiprowska ◽  
Paul Haberfield ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Natural Products ◽  
Density Functional ◽  
Bilateral Symmetry ◽  
Semiempirical Calculations ◽  
Functional Theory
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