scholarly journals Synthesis of the tetracyclic core of Illicium sesquiterpenes using an organocatalyzed asymmetric Robinson annulation

2013 ◽  
Vol 9 ◽  
pp. 1135-1140 ◽  
Author(s):  
Lynnie Trzoss ◽  
Jing Xu ◽  
Michelle H Lacoske ◽  
Emmanuel A Theodorakis
Keyword(s):  
Natural Products ◽  
Neurodegenerative Diseases ◽  
Therapeutic Potential ◽  
Enantioselective Synthesis ◽  
Diversity Oriented Synthesis ◽  
Efficient Approach ◽  
The Core ◽  
Tetracyclic Core ◽  
Robinson Annulation ◽  
Core Framework

An enantioselective synthesis of the core framework of neurotrophic Illicium majucin-type sesquiterpenes is described here. This strategy is based on an organocatalyzed asymmetric Robinson annulation and provides an efficient approach for a diversity-oriented synthesis of Illicium natural products that holds remarkable therapeutic potential for neurodegenerative diseases.

Synthesis of Polycyclic Frameworks through Iron-Catalyzed Intramolecular [5+2] Cycloaddition

Synlett ◽  
2018 ◽  
Vol 29 (15) ◽  
pp. 1978-1982 ◽  
Author(s):  
Shaomin Fu ◽  
Bo Liu ◽  
Yongjiang Liu ◽  
Yanhui Zhang ◽  
Xiao Wang
Keyword(s):  
Claisen Rearrangement ◽  
Aldol Reaction ◽  
Diterpenoid Alkaloids ◽  
Wacker Oxidation ◽  
Efficient Approach ◽  
The Core ◽  
Grignard Addition ◽  
Tetracyclic Core

A concise and efficient approach to the core of the C18/C19 diterpenoid alkaloids and phomopsterone B is reported. Both syntheses share the same iron-catalyzed intramolecular [5+2] cycloaddition to assemble the tricyclo[6.3.1.01,6]]dodecane skeleton. The following ­approach to the 6/5/6/7 tetracyclic core scaffold of C18/C19 diterpenoid alkaloids features a regioselective Grignard addition/thermal Claisen rearrangement/RCM cyclization. Meanwhile the synthetic steps to access the spiro 6/5/6 tricyclic subunits of phomopsterone B were characterized as intramolecular aldol reaction, Wacker oxidation, and Criegee ­reaction.

scholarly journals Natural Products and Their Bioactive Compounds: Neuroprotective Potentials against Neurodegenerative Diseases

2020 ◽  
Vol 2020 ◽  
pp. 1-30 ◽  
Author(s):  
Nur Shafika Mohd Sairazi ◽  
K. N. S. Sirajudeen
Keyword(s):  
Cell Death ◽  
Natural Products ◽  
Neurodegenerative Diseases ◽  
Bioactive Compounds ◽  
Therapeutic Potential ◽  
Neuroprotective Effect ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Neuronal Structure ◽  
And Function

In recent years, natural products, which originate from plants, animals, and fungi, together with their bioactive compounds have been intensively explored and studied for their therapeutic potentials for various diseases such as cardiovascular, diabetes, hypertension, reproductive, cancer, and neurodegenerative diseases. Neurodegenerative diseases, including Alzheimer’s disease, Huntington’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis are characterized by the progressive dysfunction and loss of neuronal structure and function that resulted in the neuronal cell death. Since the multifactorial pathological mechanisms are associated with neurodegeneration, targeting multiple mechanisms of actions and neuroprotection approach, which involves preventing cell death and restoring the function to damaged neurons, could be promising strategies for the prevention and therapeutic of neurodegenerative diseases. Natural products have emerged as potential neuroprotective agents for the treatment of neurodegenerative diseases. This review focused on the therapeutic potential of natural products and their bioactive compounds to exert a neuroprotective effect on the pathologies of neurodegenerative diseases.

A Pharmacological Appraisal of Neuroprotective and Neurorestorative Flavonoids Against Neurodegenerative Diseases

2019 ◽  
Vol 18 (2) ◽  
pp. 103-114 ◽  
Author(s):  
Jia Zhao ◽  
Mengxia Zhu ◽  
Mukesh Kumar ◽  
Fung Yin Ngo ◽  
Yinghui Li ◽  
...  
Keyword(s):  
Natural Products ◽  
Side Effects ◽  
Neurodegenerative Diseases ◽  
Elderly Population ◽  
The Elderly ◽  
Novel Therapeutics ◽  
The Core ◽  
Naturally Occurring ◽  
Underlying Mechanisms ◽  
Core Symptoms

Background & Objective: Alzheimer’s disease (AD) and Parkinson’s disease (PD) affect an increasing number of the elderly population worldwide. The existing treatments mainly improve the core symptoms of AD and PD in a temporary manner and cause alarming side effects. Naturally occurring flavonoids are well-documented for neuroprotective and neurorestorative effects against various neurodegenerative diseases. Thus, we analyzed the pharmacokinetics of eight potent natural products flavonoids for the druggability and discussed the neuroprotective and neurorestorative effects and the underlying mechanisms. Conclusion: This review provides valuable clues for the development of novel therapeutics against neurodegenerative diseases.

scholarly journals Synthesis of the Core Framework of the Cornexistins by Intramolecular Nozaki-Hiyama-Kishi Coupling

Molecules ◽  
2019 ◽  
Vol 24 (14) ◽  
pp. 2654
Author(s):  
Anthony Aimon ◽  
Louis J. Farrugia ◽  
J. Stephen Clark
Keyword(s):  
Natural Products ◽  
Direct Approach ◽  
Allylic Alcohols ◽  
Relative Configuration ◽  
The Core ◽  
Core Framework

A new and direct approach to the construction of the core framework of the herbicidal natural products cornexistin and hydroxycornexistin has been developed. Formation of the nine-membered carbocycle found in the natural products has been accomplished by an intramolecular Nozaki-Hiyama-Kishi reaction between a vinylic iodide and an aldehyde. Good yields of carbocyclic products were obtained from the reaction, but diastereomeric mixtures of allylic alcohols were produced. The cyclisation reaction was successful irrespective of the relative configuration of the stereogenic centres in the cyclisation precursor.

Synthesis of Spongidine A, D and Petrosaspongiolide L Methyl Ester Using Pyridine C-H Functionalization

2019 ◽  
Author(s):  
Florian Bartels ◽  
Manuela Weber ◽  
Mathias Christmann
Keyword(s):  
Natural Products ◽  
Methyl Ester ◽  
Hydrogen Atom ◽  
Phospholipase A2 ◽  
Late Stage ◽  
Hydrogen Atom Transfer ◽  
Ring System ◽  
Tetracyclic Core ◽  
Intramolecular Hydrogen ◽  
Phospholipase A2 Inhibitors

<div>An efficient strategy for the synthesis of the potent phospholipase A2 inhibitors spongidine A and D is presented. The tetracyclic core of the natural products was assembled via an intramolecular hydrogen atom transfer‐initiated Minisci reaction. A divergent late‐stage functionalization of the tetracyclic ring system was also used to achieve a concise synthesis of petrosaspongiolide L methyl ester.</div>

Natural Products for the Treatment of Neurodegenerative Diseases

2020 ◽  
Vol 27 (34) ◽  
pp. 5790-5828 ◽  
Author(s):  
Ze Wang ◽  
Chunyang He ◽  
Jing-Shan Shi
Keyword(s):  
Nervous System ◽  
Natural Products ◽  
Neurodegenerative Diseases ◽  
Neuroprotective Effect ◽  
Rapid Development ◽  
New Drugs ◽  
Progressive Degeneration ◽  
Cord Injury ◽  
The Central Nervous System ◽  
And Function

Neurodegenerative diseases are a heterogeneous group of disorders characterized by the progressive degeneration of the structure and function of the central nervous system or peripheral nervous system. Alzheimer&#039;s Disease (AD), Parkinson&#039;s Disease (PD) and Spinal Cord Injury (SCI) are the common neurodegenerative diseases, which typically occur in people over the age of 60. With the rapid development of an aged society, over 60 million people worldwide are suffering from these uncurable diseases. Therefore, the search for new drugs and therapeutic methods has become an increasingly important research topic. Natural products especially those from the Traditional Chinese Medicines (TCMs), are the most important sources of drugs, and have received extensive interest among pharmacist. In this review, in order to facilitate further chemical modification of those useful natural products by pharmacists, we will bring together recent studies in single natural compound from TCMs with neuroprotective effect.

Involvement of Heme Oxygenase-1 in Neuropsychiatric and Neurodegenerative Diseases

2018 ◽  
Vol 24 (20) ◽  
pp. 2283-2302 ◽  
Author(s):  
Vivian B. Neis ◽  
Priscila B. Rosa ◽  
Morgana Moretti ◽  
Ana Lucia S. Rodrigues
Keyword(s):  
Neurodegenerative Diseases ◽  
Heme Oxygenase ◽  
Therapeutic Potential ◽  
Redox Homeostasis ◽  
Antioxidant Defenses ◽  
Heme Oxygenase 1 ◽  
Physiological Conditions ◽  
And Oxidative Stress ◽  
Defensive Mechanism

Heme oxygenase (HO) family catalyzes the conversion of heme into free iron, carbon monoxide and biliverdin. It possesses two well-characterized isoforms: HO-1 and HO-2. Under brain physiological conditions, the expression of HO-2 is constitutive, abundant and ubiquitous, whereas HO-1 mRNA and protein are restricted to small populations of neurons and neuroglia. HO-1 is an inducible enzyme that has been shown to participate as an essential defensive mechanism for neurons exposed to oxidant challenges, being related to antioxidant defenses in certain neuropathological conditions. Considering that neurodegenerative diseases (Alzheimer’s Disease (AD), Parkinson’s Disease (PD) and Multiple Sclerosis (MS)) and neuropsychiatric disorders (depression, anxiety, Bipolar Disorder (BD) and schizophrenia) are associated with increased inflammatory markers, impaired redox homeostasis and oxidative stress, conditions that may be associated with alterations in HO-levels/activity, the purpose of this review is to present evidence on the possible role of HO-1 in these Central Nervous System (CNS) diseases. In addition, the possible therapeutic potential of targeting brain HO-1 is explored in this review.

Natural Products: Experimental Efficient Agents for Inflammatory Bowel Disease Therapy

2020 ◽  
Vol 25 (46) ◽  
pp. 4893-4913 ◽  
Author(s):  
Fan Cao ◽  
Jie Liu ◽  
Bing-Xian Sha ◽  
Hai-Feng Pan
Keyword(s):  
Inflammatory Bowel Disease ◽  
Natural Products ◽  
Immune System ◽  
Bowel Disease ◽  
Therapeutic Potential ◽  
Adaptive Immune System ◽  
Receptor Protein ◽  
Intestinal Epithelia ◽  
Inflammatory Bowel ◽  
The Individual

: Inflammatory bowel disease (IBD) is a chronic, elusive disorder resulting in relapsing inflammation of intestine with incompletely elucidated etiology, whose two representative forms are ulcerative colitis (UC) and Crohn’s disease (CD). Accumulating researches have revealed that the individual genetic susceptibility, environmental risk elements, intestinal microbial flora, as well as innate and adaptive immune system are implicated in the pathogenesis and development of IBD. Despite remarkable progression of IBD therapy has been achieved by chemical drugs and biological therapies such as aminosalicylates, corticosteroids, antibiotics, anti-tumor necrosis factor (TNF)-α, anti-integrin agents, etc., healing outcome still cannot be obtained, along with inevitable side effects. Consequently, a variety of researches have focused on exploring new therapies, and found that natural products (NPs) isolated from herbs or plants may serve as promising therapeutic agents for IBD through antiinflammatory, anti-oxidant, anti-fibrotic and anti-apoptotic effects, which implicates the modulation on nucleotide- binding domain (NOD) like receptor protein (NLRP) 3 inflammasome, gut microbiota, intestinal microvascular endothelial cells, intestinal epithelia, immune system, etc. In the present review, we will summarize the research development of IBD pathogenesis and current mainstream therapy, as well as the therapeutic potential and intrinsic mechanisms of NPs in IBD.

Potential for Treatment of Neurodegenerative Diseases with Natural Products or Synthetic Compounds that Stabilize Microtubules

2020 ◽  
Vol 26 (35) ◽  
pp. 4362-4372
Author(s):  
John H. Miller ◽  
Viswanath Das
Keyword(s):  
Natural Products ◽  
Neurodegenerative Diseases ◽  
In Vivo Models ◽  
Synthetic Compounds ◽  
Stabilizing Agents ◽  
Animal Models Of Disease ◽  
Model Studies ◽  
Models Of Disease

No effective therapeutics to treat neurodegenerative diseases exist, despite significant attempts to find drugs that can reduce or rescue the debilitating symptoms of tauopathies such as Alzheimer’s disease, Parkinson’s disease, frontotemporal dementia, amyotrophic lateral sclerosis, or Pick’s disease. A number of in vitro and in vivo models exist for studying neurodegenerative diseases, including cell models employing induced-pluripotent stem cells, cerebral organoids, and animal models of disease. Recent research has focused on microtubulestabilizing agents, either natural products or synthetic compounds that can prevent the axonal destruction caused by tau protein pathologies. Although promising results have come from animal model studies using brainpenetrant natural product microtubule-stabilizing agents, such as paclitaxel analogs that can access the brain, epothilones B and D, and other synthetic compounds such as davunetide or the triazolopyrimidines, early clinical trials in humans have been disappointing. This review aims to summarize the research that has been carried out in this area and discuss the potential for the future development of an effective microtubule stabilizing drug to treat neurodegenerative disease.

Enantioselective Syntheses of Flavonoid Diels-Alder Natural Products: A Review

2018 ◽  
Vol 15 (2) ◽  
pp. 221-229 ◽  
Author(s):  
Shah Bakhtiar Nasir ◽  
Noorsaadah Abd Rahman ◽  
Chin Fei Chee
Keyword(s):  
Natural Products ◽  
Organic Synthesis ◽  
Lewis Acid ◽  
Alder Reaction ◽  
Diels Alder ◽  
Enantioselective Synthesis ◽  
Chiral Ligand ◽  
Asymmetric Syntheses ◽  
Diels Alder Reaction ◽  
Enantioselective Syntheses

Background: The Diels-Alder reaction has been widely utilised in the syntheses of biologically important natural products over the years and continues to greatly impact modern synthetic methodology. Recent discovery of chiral organocatalysts, auxiliaries and ligands in organic synthesis has paved the way for their application in Diels-Alder chemistry with the goal to improve efficiency as well as stereochemistry. Objective: The review focuses on asymmetric syntheses of flavonoid Diels-Alder natural products that utilize chiral ligand-Lewis acid complexes through various illustrative examples. Conclusion: It is clear from the review that a significant amount of research has been done investigating various types of catalysts and chiral ligand-Lewis acid complexes for the enantioselective synthesis of flavonoid Diels-Alder natural products. The results have demonstrated improved yield and enantioselectivity. Much emphasis has been placed on the synthesis but important mechanistic work aimed at understanding the enantioselectivity has also been discussed.

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