Strain-Induced Transformations of Bicyclo[3.1.0]hex-1-enes

Synthesis ◽  
2021 ◽  
Author(s):  
Daesung Lee ◽  
Sourav Ghorai
Keyword(s):  
Natural Products ◽  
Reaction Temperature ◽  
Short Review ◽  
Highly Strained

AbstractBicyclo[3.1.0]hex-1-ene is a highly strained bicyclic intermediate that generates trimethylenemethane (TMM) diradical through breaking the C–C bond of its methylene cyclopropane moiety. The reactivity of bicyclo[3.1.0]hex-1-enes and trimethylenemethane (TMM) diradicals depend on the reaction temperature and substitution patterns. This short review covers various strain-induced transformations of bicyclo[3.1.0]hex-1-enes and their formal [3+2] cycloadditions through TMM diradicals and presents synthetic applications to natural products containing triquinane and tropone structures.1 Introduction2 Early Reports on Bicyclo[3.1.0]hex-1-enes3 Approaches to Form Bicyclo[3.1.0]hex-1-enes4 Structure and Reactivity of Bicyclo[3.1.0]hex-1-enes4.1 Isomerization4.2 Dimerization4.3 [3+2] Cycloaddition4.4 [4+2] Cycloaddition5 Synthetic Applications to Natural Products6 Summary and Outlook

Oligodendroglial glycolipids in (Re)myelination: implications for multiple sclerosis research

2021 ◽  
Author(s):  
Luise Nowack ◽  
Charlotte S. Teschers ◽  
Stefanie Albrecht ◽  
Ryan Gilmour
Keyword(s):  
Multiple Sclerosis ◽  
Natural Products ◽  
Short Review ◽  
Biological Relevance

This short review surveys aspects of glycolipid-based natural products and their biological relevance in multiple sclerosis (MS).

scholarly journals APPLICATION OF IMAGE-BASED HIGH CONTENT ANALYSIS FOR THE SCREENING OF BIOACTIVE NATURAL PRODUCTS

2018 ◽  
Vol 56 (4A) ◽  
pp. 1
Author(s):  
Do Huu Nghi ◽  
Le Mai Huong
Keyword(s):  
Natural Products ◽  
High Throughput ◽  
Cell Biology ◽  
Fluorescent Dyes ◽  
Bioactive Compound ◽  
Short Review ◽  
Biologically Active ◽  
Target Cells ◽  
Cellular Targets ◽  
Bioactive Natural Products

Each bioactive compound induces phenotypic changes in target cells that can be made visible by labelling selected molecules of the cells with fluorescent dyes and/or directly observed under the high-throughput microscope. A comparison of the cellular phenotype induced by a compound of interest with known cellular targets allows predicting its mode of action. Over the past 15 years, high-throughput microscopy has been one of the fastest growing fields in cell biology. When combined with automated multiparametric image and data analysis, it is referred to as high-content screening (HCS). Whilst HCS has been successfully applied to the bioactivity characterization of natural products, recent studies used automated microscopy and software to increase speed and to reduce subjective interpretation. In 2017, Institute of Natural Products Chemistry (INPC-VAST) has been equipped with a HCS platform (Olympus Scan^R) that designed for fully automated image acquisition and analysis of biological samples to visually inspect the cellular morphology induced by hit compounds as well as to discriminate from false positives. Accordingly, this short review covers the concepts of HCS and its application in screening of biologically active natural products whose molecular targets could be identified through such approaches.

Biosynthesis of Flavour-Active Esters via Lipase-Mediated Reactions and Mechanisms

2014 ◽  
Vol 67 (10) ◽  
pp. 1373 ◽  
Author(s):  
Jingcan Sun ◽  
Liang Wei Wilson Lee ◽  
Shao Quan Liu
Keyword(s):  
Natural Products ◽  
Industrial Production ◽  
Large Scale ◽  
Short Review ◽  
Enzyme Properties ◽  
Reaction Conditions ◽  
Active Esters ◽  
Catalyzed Reactions

Flavour active esters belong to one group of fine aroma chemicals that impart desirable fruity flavour notes and are widely applied in the flavour and fragrance industry. Due to the increasing consumer concern about health, natural products are attracting more attention than chemically synthesized substances. The biosynthesis of flavour-active esters via lipase-catalyzed reactions is one of the most important biotechnological methods for natural flavour generation. To proceed with the industrial production of esters on a large scale, it is critical to understand the enzyme properties and behaviours under different reaction conditions. In this short review, the lipase-catalyzed reactions in various systems and their mechanisms for synthesis of the esters are summarized and discussed.

Transition Metal-Catalyzed Enantioselective α-Arylation of Carbonyl Compounds to Give Tertiary Stereocenters

Synthesis ◽  
2021 ◽  
Author(s):  
Manuel Orlandi ◽  
Margarita Escudero-Casao ◽  
Giulia Licini
Keyword(s):  
Natural Products ◽  
Transition Metal ◽  
Carbonyl Group ◽  
Carbonyl Compounds ◽  
Short Review ◽  
Transition Metal Catalysis ◽  
Biologically Active ◽  
Metal Catalysis ◽  
Quaternary Stereocenters ◽  
Metal Catalyzed

Enantioenriched α-aryl carbonyl compounds are ubiquitous in natural products and biologically active compounds. Their synthesis has been explored over the last few decades and several methods now exist that allow for the enantioselective formation of a C(sp3)-C(sp2) bond in α-position to a carbonyl group. However, although the formation of quaternary stereocenters has been fairly well established, the enantioselective formation of tertiary stereocenters proved more challenging due to facile product post-reaction racemization. In this short review, we summarize the methods reported so far for the asymmetric α-arylation of enolates and analogues that rely on transition metal catalysis.

Isoxazol-5-ones as Strategic Building Blocks in Organic Synthesis

Synthesis ◽  
2018 ◽  
Vol 50 (13) ◽  
pp. 2473-2489 ◽  
Author(s):  
Amanda da Silva ◽  
Alessandra Fernandes ◽  
Samuel Thurow ◽  
Mateus Stivanin ◽  
Igor Jurberg
Keyword(s):  
Natural Products ◽  
Biological Activity ◽  
Organic Synthesis ◽  
Building Block ◽  
Building Blocks ◽  
Short Review ◽  
Preparation Methods ◽  
Drug Candidates ◽  
General Aspects

Isoxazol-5-one rings have been identified as relevant motifs in drug candidates, agrochemicals, and materials. Furthermore, this heterocycle has been also applied as a versatile building block for the preparation of a variety of densely functionalized molecules. This short review will present the most representative applications of isoxazol-5-ones in organic synthesis while discussing their properties and reactivity.1 Introduction1.1 General Aspects1.1.1 Tautomerism1.1.2 Importance: Natural Products Isolation, Biological Activity, and Materials1.1.3 Preparation Methods2 Isoxazol-5-ones in Organic Synthesis2.1 General Reactivity2.2 Specific Examples2.2.1 Alkylation Strategies2.2.2 Alkyne Synthesis2.2.3 Annulation Reactions2.2.4 N–O Bond Insertions2.2.4.1 Preparation of 1,3-Oxazin-6-ones3 Conclusions

scholarly journals The The colourful chemistry of South African latrunculid sponges

2019 ◽  
Vol 115 (5/6) ◽  
Author(s):  
Michael T. Davies-Coleman ◽  
Edith M. Antunes ◽  
Denzil R. Beukes ◽  
Toufiek Samaai
Keyword(s):  
Natural Products ◽  
South African ◽  
Marine Natural Products ◽  
Marine Invertebrates ◽  
Short Review ◽  
Marine Sponges ◽  
Organic Chemical ◽  
Sponge Tissue ◽  
Western Cape ◽  
Rich Diversity

Marine sponges – in common with many other sessile marine invertebrates seemingly devoid of obvious physical forms of defence against predators, e.g. spines or shells – are the sources of a diverse array of organic chemical compounds known as marine natural products or secondary metabolites. Recent research has indicated that the production of natural products via cellular secondary metabolic pathways in some sponge species may not occur within the sponge cells themselves, but rather in microbial endosymbionts which inhabit the surface and interstitial spaces within the sponge tissue. Regardless of their biosynthetic origin, the bioactivity, e.g. toxicity, of many of these marine natural products may be utilised by sponges as chemical feeding deterrents to discourage predation or to provide a chemical anti-fouling competitive edge in the intense competition for living space amongst filter-feeders on space-limited benthic reefs. Paradoxically, a small number of sponge natural products have serendipitously shown potential as new pharmaceuticals, e.g. novel anti-cancer drugs. Marine biodiscovery (or bioprospecting) is the search for new pharmaceuticals from marine organisms. Exploration of the taxonomy, natural products chemistry and biomedicinal potential of the rich diversity of South African latrunculid sponges (family Latrunculiidae), at Rhodes University, the South African Department of Environmental Affairs and the University of the Western Cape has continued unabated for over a quarter of a century as part of a collaborative marine biodiscovery programme. A short review of this multidisciplinary latrunculid sponge research is presented here.

Catalytic Asymmetric Osmium-Free Dihydroxylation of Alkenes

Synthesis ◽  
2020 ◽  
Author(s):  
Chuan Wang ◽  
Shixia Su
Keyword(s):  
Natural Products ◽  
Organic Synthesis ◽  
Phase Transfer ◽  
Building Blocks ◽  
Short Review ◽  
Optically Active ◽  
Asymmetric Dihydroxylation ◽  
A Subunit ◽  
Vicinal Diols ◽  
Catalytic Asymmetric

AbstractAsymmetric dihydroxylation of alkenes is one of the cornerstone reactions in organic synthesis, providing a direct entry to optically active vicinal diols, which are not only a subunit in natural products but also versatile building blocks. In recent years, considerable progress in catalytic asymmetric osmium-free dihydroxylation has been achieved. This short review presents a concise summary of the reported methods of catalytic asymmetric osmium-free dihydroxylation.1 Introduction2 Iron-Catalyzed Asymmetric syn-Dihydroxylation of Alkenes3 Manganese-Catalyzed Asymmetric syn-Dihydroxylation of Alkenes4 Palladium/Gold Bimetallic Nanocluster-Catalyzed Asymmetric syn-Dihydroxylation of Alkenes5 Enzyme-Catalyzed Asymmetric anti-Dihydroxylation of Alkenes6 Amine-Catalyzed Asymmetric Formal anti-Dihydroxylation of Enals7 Diselenide-Catalyzed anti-Dihydroxylation of Alkenes8 Molybdenum-Catalyzed Asymmetric anti-Dihydroxylation of Allylic­ Alcohols9 Phase-Transfer-Catalyzed Asymmetric Dihydroxylation of α-Aryl Acrylates10 Conclusion

scholarly journals Several Alkaloids Derived from Plants and Their Underlying Molecular Mechanisms of Action in the Fight Against Cancer

2016 ◽  
Vol 35 (2) ◽  
pp. 83
Author(s):  
Siribhorn Madla ◽  
Potchanapond Graidist
Keyword(s):  
Natural Products ◽  
Anticancer Agents ◽  
Animal Studies ◽  
Molecular Mechanisms ◽  
Causes Of Death ◽  
Short Review ◽  
Mechanisms Of Action ◽  
Apoptosis Pathways ◽  
Potential Use

Multidrug resistance is one of the major obstacles to successful cancer chemotherapy, which causes cancer to remain one of the leading causes of death worldwide. Therefore, the use of natural products for cancer prevention and therapy has been continuously investigated and developed for decades. Alkaloids are one of the important compounds derived from natural products that have been extensively studied for their potential use as cancer chemopreventive and chemotherapeutic drugs in both in vitro and animal studies. This short review intends to present the molecular mechanisms of action of alkaloids on stimulation and inhibition some signaling molecules involved in cell proliferation, differentiation, angiogenesis, metastasis and apoptosis pathways of cancer cells. The understanding of the molecular mechanisms of alkaloids against cancer will provide clues towards a diagnostic, prevention and therapeutic applications. Based on the information provided in this article, alkaloids show remarkable potential as anticancer agents. However, more research and clinical trials are crucial before applying any of these alkaloids as new medicine to treat cancer patients. 

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