Computational Studies of the Tropone Natural Products, Thiotropocin, Tropodithietic Acid, and Troposulfenin. Significance of Thiocarbonyl−Enol Tautomerism

2008 ◽  
Vol 73 (1) ◽  
pp. 280-283 ◽  
Author(s):  
Edyta M. Greer ◽  
David Aebisher ◽  
Alexander Greer ◽  
Ronald Bentley
Keyword(s):  
Natural Products ◽  
Computational Studies ◽  
Tropodithietic Acid

Synthesis of Polycycles and Oxacycles by Tandem Metathesis of endo–norbornene Derivatives

Synthesis ◽  
2021 ◽  
Author(s):  
Sambasivarao Kotha ◽  
Sunil Pulletikurti ◽  
Ambareen Fatma ◽  
gopal dhangar ◽  
gonna somu Naidu
Keyword(s):  
Natural Products ◽  
Metal Complex ◽  
Carbonyl Group ◽  
Single Step ◽  
Time Dependent ◽  
Computational Studies ◽  
Nmr Studies ◽  
Tricyclic Compounds ◽  
One Step ◽  
Norbornene Derivatives

Here, we have demonstrated that the presence of a carbonyl group at C7 position is preventing the olefin metathesis of endo-norbornene derivatives due to the complexation of the metal alkylidene. Time-dependent NMR studies showed the presence of new proton signals in the metal alkylidene region, which indicate the formation of metal complex with the carbonyl group of the substrate. These observations were further proved by ESI-MS analysis. Whereas, computational studies provided that the catalyst was interacting with the C7 carbonyl group and aligned perpendicular to that of norbornene olefin. Later, these endo-keto norbornene derivatives were reduced to hydroxyl derivatives diastereoselectively. Ring-rearrangement metathesis (RRM) of these hydroxyl derivatives, produced the [6/5/6], and [5/6/5] carbo-tricyclic cores of the natural products in one step. Whereas the RRM of O-allyl derivatives, delivered the oxa-tricyclic compounds in a single step with excellent yields.

scholarly journals Anti-selective [3+2] (Hetero)annulation of non-conjugated alkenes via directed nucleopalladation

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Hui-Qi Ni ◽  
Ilia Kevlishvili ◽  
Pranali G. Bedekar ◽  
Joyann S. Barber ◽  
Shouliang Yang ◽  
...  
Keyword(s):  
Natural Products ◽  
Functional Groups ◽  
Oxidative Addition ◽  
Reductive Elimination ◽  
Direct Access ◽  
Computational Studies ◽  
Preliminary Results ◽  
Carbon Based

Abstract2,3-Dihydrobenzofurans and indolines are common substructures in medicines and natural products. Herein, we describe a method that enables direct access to these core structures from non-conjugated alkenyl amides and ortho-iodoanilines/phenols. Under palladium(II) catalysis this [3 + 2] heteroannulation proceeds in an anti-selective fashion and tolerates a wide variety of functional groups. N-Acetyl, -tosyl, and -alkyl substituted ortho-iodoanilines, as well as free –NH2 variants, are all effective. Preliminary results with carbon-based coupling partners also demonstrate the viability of forming indane core structures using this approach. Experimental and computational studies on reactions with phenols support a mechanism involving turnover-limiting, endergonic directed oxypalladation, followed by intramolecular oxidative addition and reductive elimination.

In vitro and computational studies of natural products related to perezone as anti-neoplastic agents

Biochimie ◽  
2020 ◽  
Vol 171-172 ◽  
pp. 158-169 ◽  
Author(s):  
Maricarmen Hernández-Rodríguez ◽  
Pablo I. Mendoza Sánchez ◽  
Martha Edith Macías Perez ◽  
Erika Rosales Cruz ◽  
Elvia Mera Jiménez ◽  
...  
Keyword(s):  
Natural Products ◽  
Computational Studies

Computational Studies on the Substrate Specificity of an Acyltransferase Domain from Salinomycin Polyketide Synthase

2021 ◽  
Author(s):  
Huining Ji ◽  
Ting Shi ◽  
Lei Liu ◽  
Fa Zhang ◽  
Wentao Tao ◽  
...  
Keyword(s):  
Natural Products ◽  
Substrate Specificity ◽  
Polyketide Synthase ◽  
Coenzyme A ◽  
Biological Activities ◽  
Polyketide Synthases ◽  
Short Chain ◽  
Computational Studies ◽  
Chemical Structures ◽  
Coa Thioesters

Polyketides are a large group of natural products with diverse chemical structures and biological activities. They are biosynthesized by modular polyketide synthases (PKSs) from coenzyme A (CoA) thioesters of short-chain...

scholarly journals Computational Studies Applied to Flavonoids against Alzheimer’s and Parkinson’s Diseases

2018 ◽  
Vol 2018 ◽  
pp. 1-21 ◽  
Author(s):  
Alex France M. Monteiro ◽  
Jéssika De O. Viana ◽  
Anuraj Nayarisseri ◽  
Ernestine N. Zondegoumba ◽  
Francisco Jaime B. Mendonça Junior ◽  
...  
Keyword(s):  
Natural Products ◽  
Molecular Docking ◽  
Neurodegenerative Diseases ◽  
In Silico ◽  
Docking Studies ◽  
Binding Energies ◽  
Computational Studies ◽  
Epicatechin Gallate ◽  
Drug Candidates ◽  
Parkinson’S Diseases

Neurodegenerative diseases, such as Parkinson’s and Alzheimer’s, are understood as occurring through genetic, cellular, and multifactor pathophysiological mechanisms. Several natural products such as flavonoids have been reported in the literature for having the capacity to cross the blood-brain barrier and slow the progression of such diseases. The present article reports on in silico enzymatic target studies and natural products as inhibitors for the treatment of Parkinson’s and Alzheimer’s diseases. In this study we evaluated 39 flavonoids using prediction of molecular properties and in silico docking studies, while comparing against 7 standard reference compounds: 4 for Parkinson’s and 3 for Alzheimer’s. Osiris analysis revealed that most of the flavonoids presented no toxicity and good absorption parameters. The Parkinson’s docking results using selected flavonoids as compared to the standards with four proteins revealed similar binding energies, indicating that the compounds 8-prenylnaringenin, europinidin, epicatechin gallate, homoeriodictyol, capensinidin, and rosinidin are potential leads with the necessary pharmacological and structural properties to be drug candidates. The Alzheimer’s docking results suggested that seven of the 39 flavonoids studied, being those with the best molecular docking results, presenting no toxicity risks, and having good absorption rates (8-prenylnaringenin, europinidin, epicatechin gallate, homoeriodictyol, aspalathin, butin, and norartocarpetin) for the targets analyzed, are the flavonoids which possess the most adequate pharmacological profiles.

scholarly journals Molecular Basis for Spirocycle Formation in the Paraherquamide Biosynthetic Pathway

2019 ◽  
Author(s):  
Amy E. Fraley ◽  
Kersti Caddell Haatveit ◽  
Ying Ye ◽  
Samantha P. Kelly ◽  
Sean A. Newmister ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Natural Products ◽  
Molecular Dynamics Simulations ◽  
Molecular Basis ◽  
Biosynthetic Pathway ◽  
Three Dimensional ◽  
Enzymatic Reactions ◽  
Computational Studies ◽  
Penicillium Simplicissimum ◽  
Dynamics Simulations

<div> <div> <div> <p>The paraherquamides are potent anthelmintic natural products with complex heptacyclic scaffolds. One key feature of these molecules is the spiro-oxindole moiety that lends a strained three-dimensional architecture to these structures. The flavin monooxygenase PhqK was found to catalyze spirocycle formation through two parallel pathways in the biosynthesis of paraherquamides A and G. Two new paraherquamides (K and L) were isolated from a ΔphqK strain of Penicillium simplicissimum, and subsequent enzymatic reactions with these compounds generated two additional metabolites paraherquamides M and N. Crystal structures of PhqK in complex with various substrates provided a foundation for mechanistic analyses and computational studies. While it is evident that PhqK can react with various substrates, reaction kinetics and molecular dynamics simulations indicated that the dioxepin-containing paraherquamide L was the favored substrate. Through this effort, we have elucidated a key step in the biosynthesis of the paraherquamides, and provided a rationale for the selective spirocyclization of these powerful anthelmintic agents. </p></div></div><div><div> </div> </div> </div>

Sign in / Sign up

Export Citation Format

Share Document