Chemistry › Organic Chemistry

Chemical synthesis and alkaloids

Works Count: 68588

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Description

This cluster of papers focuses on the chemistry, pharmacology, synthesis, and biological activities of Amaryllidaceae alkaloids such as galanthamine, narciclasine, and lycorine. These natural compounds show potential as anticancer agents, acetylcholinesterase inhibitors, and have medicinal significance. The research also explores their structure-activity relationships and potential therapeutic applications.

Keywords

Amaryllidaceae; Alkaloids; Galanthamine; Narciclasine; Lycorine; Anticancer; Acetylcholinesterase Inhibitors; Synthesis; Biological Activity; Medicinal Potential

The Renaissance of Natural Products as Drug Candidates

2005-10-21

Ian Paterson , Edward A. Anderson

Article MetricsDownloadsCitationsNo data available.051015JulAugSepOctNovDec6600Total6 Months12 MonthsTotal number of downloads for the most recent 6 whole calendar months. Article MetricsDownloadsCitationsNo data available.051015JulAugSepOctNovDec6600Total6 Months12 MonthsTotal number of downloads for the most recent 6 whole calendar months.

A Text-Book of Pharmacognosy

1910-11-01

T. E. Wallis

Studies in Natural Products Chemistry

1993-01-01

Atta‐ur Rahman

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Textbook of psychopharmacology

1975-12-01

Griffith Edwards

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Cellular and molecular biology of voltage-gated sodium channels

1992-10-01

W A Catterall

Galanthamine from snowdrop—the development of a modern drug against Alzheimer’s disease from local Caucasian knowledge

2004-04-13

Michael Heinrich , Hooi Lee Teoh

Casarett and Doull's toxicology: The basic science of poisons

1996-04-01

John Pickrell

The Asymmetric Intramolecular Heck Reaction in Natural Product Total Synthesis

2003-07-08

Amy B. Dounay , Larry E. Overman

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Asymmetric Intramolecular Heck Reaction in Natural Product Total SynthesisAmy B. Dounay and Larry E. OvermanView Author Information Department of Chemistry, University of California, Irvine, California 92697-2025 … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Asymmetric Intramolecular Heck Reaction in Natural Product Total SynthesisAmy B. Dounay and Larry E. OvermanView Author Information Department of Chemistry, University of California, Irvine, California 92697-2025 Cite this: Chem. Rev. 2003, 103, 8, 2945–2964Publication Date (Web):July 8, 2003Publication History Received5 February 2003Published online8 July 2003Published inissue 1 August 2003https://pubs.acs.org/doi/10.1021/cr020039hhttps://doi.org/10.1021/cr020039hresearch-articleACS PublicationsCopyright © 2003 American Chemical SocietyRequest reuse permissionsArticle Views24937Altmetric-Citations1345LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Cyclization,Heck reaction,Hydrocarbons,Ligands,Stereoselectivity Get e-Alerts

The ester enolate Claisen rearrangement. Stereochemical control through stereoselective enolate formation

1976-05-01

Robert E. Ireland , Richard H. Mueller , Alvin K. Willard

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe ester enolate Claisen rearrangement. Stereochemical control through stereoselective enolate formationRobert E. Ireland, Richard H. Mueller, and Alvin K. WillardCite this: J. Am. Chem. Soc. 1976, 98, … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe ester enolate Claisen rearrangement. Stereochemical control through stereoselective enolate formationRobert E. Ireland, Richard H. Mueller, and Alvin K. WillardCite this: J. Am. Chem. Soc. 1976, 98, 10, 2868–2877Publication Date (Print):May 1, 1976Publication History Published online1 May 2002Published inissue 1 May 1976https://pubs.acs.org/doi/10.1021/ja00426a033https://doi.org/10.1021/ja00426a033research-articleACS PublicationsRequest reuse permissionsArticle Views8040Altmetric-Citations750LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Simple stereoselective version of the Claisen rearrangement leading to trans-trisubstituted olefinic bonds. Synthesis of squalene

1970-02-01

William S. Johnson , Lucius Werthemann , William R. Bartlett +4 more

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSimple stereoselective version of the Claisen rearrangement leading to trans-trisubstituted olefinic bonds. Synthesis of squaleneWilliam Summer Johnson, Lucius Werthemann, William R. Bartlett, Timothy J. Brocksom, Tsung-Tee Li, … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSimple stereoselective version of the Claisen rearrangement leading to trans-trisubstituted olefinic bonds. Synthesis of squaleneWilliam Summer Johnson, Lucius Werthemann, William R. Bartlett, Timothy J. Brocksom, Tsung-Tee Li, D. John Faulkner, and Michael R. PetersenCite this: J. Am. Chem. Soc. 1970, 92, 3, 741–743Publication Date (Print):February 1, 1970Publication History Published online1 May 2002Published inissue 1 February 1970https://pubs.acs.org/doi/10.1021/ja00706a074https://doi.org/10.1021/ja00706a074research-articleACS PublicationsRequest reuse permissionsArticle Views6820Altmetric-Citations573LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Construction of Spiro[pyrrolidine‐3,3′‐oxindoles] − Recent Applications to the Synthesis of Oxindole Alkaloids

2003-06-01

Christiane Marti , Erick M. Carreira

Abstract The spiro[pyrrolidine‐3,3′‐oxindole] ring system is found at the core of a number of alkaloids, which possess significant biological activity and are interesting, challenging targets for chemical synthesis. In the … Abstract The spiro[pyrrolidine‐3,3′‐oxindole] ring system is found at the core of a number of alkaloids, which possess significant biological activity and are interesting, challenging targets for chemical synthesis. In the present review, we report on the different strategies for the synthesis of the spiro[pyrrolidine‐3,3′‐oxindole] ring system in the context of recent synthesis of coerulescine, horsfiline, elacomine, salacin, pteropodine, alstonisine, spirotryprostatin A and B, and strychnofoline. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

On the localization of acetylcholine receptors

1955-04-28

J. del Castillo , B. Katz

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Novel dihydropyridines with positive inotropic action through activation of Ca2+ channels

1983-06-01

Matthias Schramm , G. Thomas , R. Towart +1 more

The Chemistry of Imines.

1963-10-01

Robert W. Layer

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Chemistry of Imines.Robert W. LayerCite this: Chem. Rev. 1963, 63, 5, 489–510Publication Date (Print):October 1, 1963Publication History Published online1 May 2002Published inissue 1 October 1963https://pubs.acs.org/doi/10.1021/cr60225a003https://doi.org/10.1021/cr60225a003research-articleACS PublicationsRequest … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Chemistry of Imines.Robert W. LayerCite this: Chem. Rev. 1963, 63, 5, 489–510Publication Date (Print):October 1, 1963Publication History Published online1 May 2002Published inissue 1 October 1963https://pubs.acs.org/doi/10.1021/cr60225a003https://doi.org/10.1021/cr60225a003research-articleACS PublicationsRequest reuse permissionsArticle Views14296Altmetric-Citations864LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Synthesis of Phenanthrenes and Polycyclic Heteroarenes by Transition‐Metal Catalyzed Cycloisomerization Reactions

2004-07-29

Victor Mamane , Peter Hannen , Alois Fürstner

Abstract Readily available biphenyl derivatives containing an alkyne unit at one of their ortho ‐positions are converted into substituted phenanthrenes on exposure to catalytic amounts of either PtCl 2 , … Abstract Readily available biphenyl derivatives containing an alkyne unit at one of their ortho ‐positions are converted into substituted phenanthrenes on exposure to catalytic amounts of either PtCl 2 , AuCl, AuCl 3 , GaCl 3 or InCl 3 in toluene. This 6‐ endo ‐dig cyclization likely proceeds through initial π‐complexation of the alkyne unit followed by interception of the resulting η 2 ‐metal species by the adjacent arene ring. The reaction is inherently modular, allowing for substantial structural variations and for the incorporation of substituents at any site of the phenanthrene product. Moreover, it is readily extended to the heterocyclic series as exemplified by the preparation of benzoindoles, benzocarbazoles, naphthothiophenes, as well as bridgehead nitrogen heterocycles such as pyrrolo[1,2‐ a ]quinolines. Depending on the chosen catalyst, biaryls bearing halo‐alkyne units can either be converted into the corresponding 10‐halo‐phenanthrenes or into the isomeric 9‐halo‐phenanthrenes; in the latter case, the concomitant 1,2‐halide shift is best explained by assuming a metal vinylidene species as the reactive intermediate. The scope of this novel method for the preparation of polycyclic arenes is illustrated by the total synthesis of a series of polyoxygenated phenanthrenes that are close relatives of the anticancer agent combretastatin A‐4, as well as by the total synthesis of the aporphine alkaloid O‐methyl‐dehydroisopiline and its naturally occurring symmetrical dimer.

Chemistry of dihydropyridines

1972-02-01

Ulli Eisner , Josef Kuthan

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChemistry of dihydropyridinesUlli. Eisner and Josef. KuthanCite this: Chem. Rev. 1972, 72, 1, 1–42Publication Date (Print):February 1, 1972Publication History Published online1 May 2002Published inissue 1 February 1972https://pubs.acs.org/doi/10.1021/cr60275a001https://doi.org/10.1021/cr60275a001research-articleACS … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChemistry of dihydropyridinesUlli. Eisner and Josef. KuthanCite this: Chem. Rev. 1972, 72, 1, 1–42Publication Date (Print):February 1, 1972Publication History Published online1 May 2002Published inissue 1 February 1972https://pubs.acs.org/doi/10.1021/cr60275a001https://doi.org/10.1021/cr60275a001research-articleACS PublicationsRequest reuse permissionsArticle Views3667Altmetric-Citations744LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Intramolecular reactions of N-acyliminium intermediates

1985-01-01

W. N. SPECKAMP , Henk Hiemstra

Ueber die Synthese pyridinartiger Verbindungen aus Acetessigäther und Aldehydammoniak

1882-01-01

A. Hantzsch

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Alcohol, Amines, and Alkaloids: A Possible Biochemical Basis for Alcohol Addiction

1970-02-13

Virginia E. Davis , Michael J. Walsh

Tetrahydropapaveroline is a benzyltetrahydroisoquinoline alkaloidderivative of the biogenic amine, dopnmine. Alcohol, by way of its primary metabolite, acetaldehyde, competitively inhibits nicotinamide-adenine Sinucleotide-linked aldehyde dehydrogenase and augments the formation of tetrahydropapaveroline … Tetrahydropapaveroline is a benzyltetrahydroisoquinoline alkaloidderivative of the biogenic amine, dopnmine. Alcohol, by way of its primary metabolite, acetaldehyde, competitively inhibits nicotinamide-adenine Sinucleotide-linked aldehyde dehydrogenase and augments the formation of tetrahydropapaveroline in vitro. The limited capacity of brain to oxidize aldehydes may be of pharmacological importance because it facilitates the production of tetrahydropapaveroline in the presence of drugs which inhibit this enzyme.

Isolation and Synthesis of Biologically Active Carbazole Alkaloids

2002-11-01

Hans‐Joachim Knölker , Kethiri R. Reddy

ADVERTISEMENT RETURN TO ISSUEPREVArticleIsolation and Synthesis of Biologically Active Carbazole AlkaloidsHans-Joachim Knölker and Kethiri R. ReddyView Author Information Institut für Organische Chemie, Technische Universität Dresden, Bergstrasse 66, 01069 Dresden, Germany … ADVERTISEMENT RETURN TO ISSUEPREVArticleIsolation and Synthesis of Biologically Active Carbazole AlkaloidsHans-Joachim Knölker and Kethiri R. ReddyView Author Information Institut für Organische Chemie, Technische Universität Dresden, Bergstrasse 66, 01069 Dresden, Germany Cite this: Chem. Rev. 2002, 102, 11, 4303–4428Publication Date (Web):November 13, 2002Publication History Received24 June 2002Published online13 November 2002Published inissue 1 November 2002https://pubs.acs.org/doi/10.1021/cr020059jhttps://doi.org/10.1021/cr020059jresearch-articleACS PublicationsCopyright © 2002 American Chemical SocietyRequest reuse permissionsArticle Views16379Altmetric-Citations1217LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Aromatic compounds,Chemical synthesis,Cyclization,Organic compounds,Organic synthesis Get e-Alerts

Drug discovery from natural sources

2006-06-01

Young‐Won Chin , Marcy J. Balunas , Hee Byung Chai +1 more

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Tandem Reactions in Organic Synthesis: Novel Strategies for Natural Product Elaboration and the Development of New Synthetic Methodology

1996-01-01

Philip J. Parsons , Clive S. Penkett , Adrian Shell

Chelerythrine is a potent and specific inhibitor of protein kinase C

1990-11-01

Jean‐Marc Herbert , Jean‐Michel Augereau , J. Gleye +1 more

Collective synthesis of natural products by means of organocascade catalysis

2011-07-01

Spencer B. Jones , Bryon Simmons , Anthony Mastracchio +1 more

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The Raison d'Être of Secondary Plant Substances

1959-05-29

G. Fraenkel

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Psychopharmacology. A Review of Progress, 1957-1967

1969-09-01

Alfred Burger

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPsychopharmacology. A Review of Progress, 1957-1967Alfred BurgerCite this: J. Med. Chem. 1969, 12, 5, 963–964Publication Date (Print):September 1, 1969Publication History Published online30 December 2003Published inissue 1 September … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPsychopharmacology. A Review of Progress, 1957-1967Alfred BurgerCite this: J. Med. Chem. 1969, 12, 5, 963–964Publication Date (Print):September 1, 1969Publication History Published online30 December 2003Published inissue 1 September 1969https://pubs.acs.org/doi/10.1021/jm00305a903https://doi.org/10.1021/jm00305a903research-articleACS PublicationsRequest reuse permissionsArticle Views39Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Making carbon-nitrogen bonds in biological and chemical synthesis

2006-05-18

Ryan Hili , Andrei K. Yudin

From Nature to Drug Discovery: The Indole Scaffold as a &#x2018;Privileged Structure&#x2019;

2009-05-30

Fernando de Sa Alves , Eliezer J. Barreiro , Carlos Alberto Manssour Fraga

The indole scaffold probably represents one of the most important structural subunits for the discovery of new drug candidates. The demonstration that many alkaloids contain the indole nucleus, the recognition … The indole scaffold probably represents one of the most important structural subunits for the discovery of new drug candidates. The demonstration that many alkaloids contain the indole nucleus, the recognition of the importance of essential amino acid tryptophan in human nutrition and the discovery of plant hormones served to bring about a massive search on indole chemistry, giving rise to a vast number of biologically active natural and synthetic products, with a wide range of therapeutic targets, such as anti-inflammatories, phosphodiesterase inhibitors, 5-hydroxytryptamine receptor agonists and antagonists, cannabinoid receptors agonists and HMG-CoA reductase inhibitors. Many of these target-receptors belong to the class of GPCRs (integral membrane G-protein coupled receptors) and possess a conserved binding pocket that is recognized by the indole scaffold in a "common" complementary binding domain, explaining the great number of drugs that contain the indole substructure, such as indomethacin, ergotamine, frovatriptan, ondansetron, tadalafil, among many others.

Applications of Sulfoxides to Asymmetric Synthesis of Biologically Active Compounds

1995-09-01

M. Carmen Carreño

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTApplications of Sulfoxides to Asymmetric Synthesis of Biologically Active CompoundsM. Carmen CarrenoCite this: Chem. Rev. 1995, 95, 6, 1717–1760Publication Date (Print):September 1, 1995Publication History Published online1 May … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTApplications of Sulfoxides to Asymmetric Synthesis of Biologically Active CompoundsM. Carmen CarrenoCite this: Chem. Rev. 1995, 95, 6, 1717–1760Publication Date (Print):September 1, 1995Publication History Published online1 May 2002Published inissue 1 September 1995https://pubs.acs.org/doi/10.1021/cr00038a002https://doi.org/10.1021/cr00038a002research-articleACS PublicationsRequest reuse permissionsArticle Views3759Altmetric-Citations955LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Mechanism of inhibition of cell proliferation by Vinca alkaloids.

1991-04-15

M A Jordan , Douglas Thrower , L Wilson

We have used a structure-activity approach to investigate whether the Vinca alkaloids inhibit cell proliferation primarily by means of their effects on mitotic spindle microtubules or by another mechanism or … We have used a structure-activity approach to investigate whether the Vinca alkaloids inhibit cell proliferation primarily by means of their effects on mitotic spindle microtubules or by another mechanism or by a combination of mechanisms. Five Vinca alkaloids were used to investigate the relationship in HeLa cells between inhibition of cell proliferation and blockage of mitosis, alteration of spindle organization, and depolymerization of microtubules. Indirect immunofluorescence staining of microtubules and 4,6-diamidino-2-phenylindole staining of chromatin were used to characterize the effects of the drugs on the distributions of cells in stages of the cell cycle and on the organization of microtubules and chromosomes in metaphase spindles. The microtubule polymer was isolated from cells and quantified using a competitive enzyme-linked immunoadsorbent assay for tubulin. We observed a nearly perfect coincidence between the concentration of each Vinca derivative that inhibited cell proliferation and the concentration that caused 50% accumulation of cells at metaphase, despite the fact that the antiproliferative potencies of the drugs varied over a broad concentration range. Inhibition of cell proliferation and blockage of cells at metaphase at the lowest effective concentrations of all Vinca derivatives occurred with little or no microtubule depolymerization or spindle disorganization. With increasing drug concentrations, the organization of microtubules and chromosomes in arrested mitotic spindles deteriorated in a manner that was common to all five congeners. These results indicate that the antiproliferative activity of the Vinca alkaloids at their lowest effective concentrations in HeLa cells is due to inhibition of mitotic spindle function. The results suggest further that the Vinca alkaloids inhibit cell proliferation by altering the dynamics of tubulin addition and loss at the ends of mitotic spindle microtubules rather than by depolymerizing the microtubules. The specific alterations of spindle microtubule dynamics appear to differ among the five Vinca congeners, and such differences may be responsible for differences in the antitumor specificities of the drugs.

Chasing Molecules That Were Never There: Misassigned Natural Products and the Role of Chemical Synthesis in Modern Structure Elucidation

2005-02-01

K. C. Nicolaou , Scott A. Snyder

Abstract Over the course of the past half century, the structural elucidation of unknown natural products has undergone a tremendous revolution. Before World War II, a chemist would have relied … Abstract Over the course of the past half century, the structural elucidation of unknown natural products has undergone a tremendous revolution. Before World War II, a chemist would have relied almost exclusively on the art of chemical synthesis, primarily in the form of degradation and derivatization reactions, to develop and test structural hypotheses in a process that often took years to complete when grams of material were available. Today, a battery of advanced spectroscopic methods, such as multidimensional NMR spectroscopy and high‐resolution mass spectrometry, not to mention X‐ray crystallography, exist for the expeditious assignment of structures to highly complex molecules isolated from nature in milligram or sub‐milligram quantities. In fact, it could be argued that the characterization of natural products has become a routine task, one which no longer even requires a reaction flask! This Review makes the case that imaginative detective work and chemical synthesis still have important roles to play in the process of solving nature's most intriguing molecular puzzles.

Alkaloids: Chemical and Biological Perspectives

1992-01-01

S. William Pelletier

THE ASCENDING CHOLINERGIC RETICULAR SYSTEM: NEOCORTICAL, OLFACTORY AND SUBCORTICAL PROJECTIONS

1967-01-01

C. C. D. Shute , P. R. Lewis

Journal Article THE ASCENDING CHOLINERGIC RETICULAR SYSTEM: NEOCORTICAL, OLFACTORY AND SUBCORTICAL PROJECTIONS Get access C. C. D. SHUTE, C. C. D. SHUTE From the Anatomy School, University of Cambridge Search … Journal Article THE ASCENDING CHOLINERGIC RETICULAR SYSTEM: NEOCORTICAL, OLFACTORY AND SUBCORTICAL PROJECTIONS Get access C. C. D. SHUTE, C. C. D. SHUTE From the Anatomy School, University of Cambridge Search for other works by this author on: Oxford Academic PubMed Google Scholar P. R. LEWIS P. R. LEWIS From the Anatomy School, University of Cambridge Search for other works by this author on: Oxford Academic PubMed Google Scholar Brain, Volume 90, Issue 3, September 1967, Pages 497–520, https://doi.org/10.1093/brain/90.3.497 Published: 01 September 1967

International Union of Pharmacology classification of receptors for 5-hydroxytryptamine (Serotonin).

1994-06-01

Daniël Hoyer , David E. Clarke , John R. Fozard +5 more

It is evident that in the last decade or so, a vast amount of new information has become available concerning the various 5-HT receptor types and their characteristics. This derives … It is evident that in the last decade or so, a vast amount of new information has become available concerning the various 5-HT receptor types and their characteristics. This derives from two main research approaches, operational pharmacology, using selective ligands (both agonists and antagonists), and, more recently, molecular biology. Although the scientific community continues to deliberate about the hierarchy of criteria for neurotransmitter receptor characterisation, there seems good agreement between the two approaches regarding 5-HT receptor classification. In addition, the information regarding transduction mechanisms and second messengers is also entirely consistent. Thus, on the basis of these essential criteria for receptor characterisation and classification, there are at least three main groups or classes of 5-HT receptor: 5-HT1, 5-HT2, and 5-HT3. Each group is not only operationally but also structurally distinct, with each receptor group having its own distinct transducing system. The more recently identified 5-HT4 receptor almost undoubtedly represents a fourth 5-HT receptor class on the basis of operational and transductional data, but this will only be definitively shown when the cDNA for the receptor has been cloned and the amino acid sequence of the protein is known. Although those 5-HT receptors that have been fully characterised and classified to date (and, hence, named with confidence) would seem to mediate the majority of the actions of 5-HT throughout the mammalian body, not all receptors for 5-HT are fully encompassed within our scheme of classification. These apparent anomalies must be recognised and need further study. They may or may not represent new groups of 5-HT receptor or subtypes of already known groups of 5-HT receptor. Even though the cDNAs for the 5-ht1E, 5-ht1F, 5-ht5, 5-ht6, and 5-ht7 receptors have been cloned and their amino acid sequence defined, more data are necessary concerning their operational and transductional characteristics before one can be confident of the suitability of their appellations. Therefore, it is important to rationalise in concert all of the available data from studies involving both operational approaches of the classical pharmacological type and those from molecular and cellular biology.(ABSTRACT TRUNCATED AT 400 WORDS)

ACETYLCHOLINE METABOLISM OF A SYMPATHETIC GANGLION

1961-04-01

R. I. Birks , F. C. MacIntosh

The synthesis, storage, and release of acetylcholine (ACh) were studied in perfused and intact superior cervical ganglia of cats. ACh was determined by bio-assay in ganglion extracts and in the … The synthesis, storage, and release of acetylcholine (ACh) were studied in perfused and intact superior cervical ganglia of cats. ACh was determined by bio-assay in ganglion extracts and in the venous effluent from ganglia perfused with fluid containing an anticholinesterase drug. Of the extractable ACh in a normal ganglion, about 85% is "depot ACh" available for release by nerve impulses. This must be located in the nerve endings; most of the remainder is in the intraganglionic portions of the preganglionic axons. The depot ACh exists as two fractions, of which one, the smaller, is the more readily available for release by nerve impulses. ACh synthesis and release go on at a measurable low rate in the absence of nerve impulses; both are greatly accelerated by activity. Under physiological conditions of excitation and perfusion, ACh release does not outrun ACh synthesis; but synthesis is slowed, with consequent depletion of depot ACh and reduction in ACh release, if choline is absent from the extracellular fluid, or if the hemicholinium base HC-3 is present. The latter compound specifically inhibits ACh synthesis by competing with choline; as a result it produces delayed block in repetitively activated cholinergic pathways. For efficient synthesis of ACh during experiments lasting an hour or so, a ganglion need be supplied with no substances other than choline and the constituents of Locke's solution; for the efficient release of ACh, the perfusion fluid must also contain CO 2 and an unidentified factor present in plasma. ACh accumulates above the resting level in a ganglion whose cholinesterase has been inactivated, provided that the perfusing fluid is one that supports ACh synthesis; the additional ACh is not immediately available for release by nerve impulses. Under physiological conditions of perfusion the amount of ACh set free by each maximal preganglionic volley is highest in a ganglion that has been at rest, and is then independent of stimulation frequency; after repetitive activation for several minutes the volley output is lower and is only frequency-independent at rates of excitation below 20/second. Consideration is given to the probable intracellular locations of the several fractions of the ganglionic ACh, and to their interrelationship.

Recent developments in indole ring synthesis—methodology and applications

2000-01-01

Gordon W. Gribble

Covering: 1994–1999. Previous review: Contemp. Org. Synth., 1994, 1, 145. Covering: 1994–1999. Previous review: Contemp. Org. Synth., 1994, 1, 145.

Biochemistry of Phenolic Compounds.

1965-03-01

W. David Ollis

ADVERTISEMENT RETURN TO ISSUEPREVArticleBiochemistry of Phenolic Compounds.W. D. OllisCite this: J. Am. Chem. Soc. 1965, 87, 5, 1157–1158Publication Date (Print):March 1, 1965Publication History Published online1 May 2002Published inissue 1 March … ADVERTISEMENT RETURN TO ISSUEPREVArticleBiochemistry of Phenolic Compounds.W. D. OllisCite this: J. Am. Chem. Soc. 1965, 87, 5, 1157–1158Publication Date (Print):March 1, 1965Publication History Published online1 May 2002Published inissue 1 March 1965https://pubs.acs.org/doi/10.1021/ja01083a067https://doi.org/10.1021/ja01083a067research-articleACS PublicationsRequest reuse permissionsArticle Views163Altmetric-Citations2LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Casarett and Doull's toxicology: The basic science of poisons

1987-09-01

Morag Cunninghame , Derek Grant

Medicinal Natural Products: A Biosynthetic Approach

1998-01-01

Geoffrey C. Kite , Paul M. Dewick

Psychopharmacology. A Generation of Progress

1978-12-01

View PDF Chat

Comprehensive natural products chemistry

1999-10-01

D. H. R. BARTON , 香爾中西 , Otto Meth‐Cohn

Collecting together aspects of the chemistry of natural products, this work was conceived as a source of the underlying general principles governing modern natural products physics. Collecting together aspects of the chemistry of natural products, this work was conceived as a source of the underlying general principles governing modern natural products physics.

Modern Aldol Reactions

2004-06-24

Rainer Mahrwald

Fundamentals and Transition State Models.The Development of Titanium Enolate Based Aldol Reactions.Boron and Silicon Enolates in Crossed Aldol Reaction.Silver, Gold and Palladium Lewis-Acids.Boron and Silicon Lewis Acids for Mukaiyama Aldol … Fundamentals and Transition State Models.The Development of Titanium Enolate Based Aldol Reactions.Boron and Silicon Enolates in Crossed Aldol Reaction.Silver, Gold and Palladium Lewis-Acids.Boron and Silicon Lewis Acids for Mukaiyama Aldol Reactions.Copper Lewis Acids.Tin-promoted Aldol Reactions and Their Applications to Total Syntheses of Natural Products.Zirconium Alkoxides as Lewis Acids.Direct Catalytic Asymmetric Aldol Reaction Using Chiral Metal Complexes.Catalytic Enantioselective Aldol Additions with Chiral Lewis Bases.Amine-Catalyzed Aldol Reactions.Enzyme Catalyzed Aldol Additions.Antibody-Catalyzed Aldol Reactions.The Aldol-Tishchenko Reaction.The Aldol Reaction in Natural Product Synthesis: The Epothilone Story.

Psychopharmacology: A Generation of Progress

1978-09-01

F. J. B.

Handbook of Psychopharmacology

1978-01-01

Neuro‐Psychopharmacology

1962-06-01

Progress in Brain Research

1968-11-01

The introduction and widespread use of the scalp‐recorded electroencephalogram in psychiatry and related disciplines have raised a number of important questions regarding its signincance and interpretation. One of the most … The introduction and widespread use of the scalp‐recorded electroencephalogram in psychiatry and related disciplines have raised a number of important questions regarding its signincance and interpretation. One of the most difficult and complex of these is the relationship between the EEG and behavior. While some authorities believe the EEG is a sensitive index of specined behaviors, others are equally adamant that this association is neither regular nor constant. With the study of anticholinergic agents, the controversy has been brought into sharp focus. This intriguing area was explored at the Seventh Symposium on Anticholinergic Drugs and Brain Function in Animals and Man held in Washington, D.C. in March, 1966. This book contains the proceedings of that meeting.

Phytochemical Constituents and in-vitro antioxidant Activity of Aleuritopteris bicolor Leaves, Crinum amoenum Bulbs, and Drynaria coronans Rhizomes of Nepal

2025-06-25

Sindhu K.C. , Atisammodavardhana Kaundinnyayana , Prabhat Kumar Jha +5 more | Jordan Journal of Pharmaceutical Sciences

Background: Due to plant derived chemicals’s potential as antioxidant agents, there has been a growing interest in using them to cure or prevent diseases. Similarly plant species like Aleuritopteris bicolor(AB) … Background: Due to plant derived chemicals’s potential as antioxidant agents, there has been a growing interest in using them to cure or prevent diseases. Similarly plant species like Aleuritopteris bicolor(AB) leaves,Crinum amoenum(CA) bulbs and Drynaria coronans (DC) rhizomes are used as traditional herbal medicine in Nepal. Aims: This study aims to assess the qualitative and quantitative phytochemical constituents along with the antioxidant potency of extracts from the leaves of AB, bulbs of CA, and rhizomes of DC. Methods and Materials: The qualitative phytochemical profile was assessed using thin-layer chromatography (TLC) and standard phytochemical tests. TLC was performed on silica gel 60 F254 plates (20×20 cm, layer thickness: 0.2 mm) using a solvent system of chloroform: methanol: water at (6:4:1) ratio. Plates were visualized under UV light (254 nm and 365 nm) and further developed using 1% FeCl₃, 10% H₂SO₄, and DPPH for antioxidant activity. Quantitative analysis of total flavonoid and phenol content was conducted using aluminum chloride and Folin-Ciocalteu reagents, respectively. The antioxidant activity was measured through the DPPH free radical scavenging assay. Results: The selected species were found to contain flavonoid, phenol, saponin and tannin. Higher flavonoid and phenol content was found in the leaves of AB (398.861 ± 6.94 mg quercetin/ g dry extract) and rhizomes of CA (172.97 ± 1.777 gallic acid/ g dry extract) respectively whereas leaves of AB had the most potent antioxidant activity (IC50= 3.233 µg/ml). Conclusions: All the selected plant species were found to have significant constituents. Among them, the leaves of AB extract had the highest flavonoid concentration and the higher antioxidant activity, highlighting its potential for further medicinal use. Keywords: Phytochemical screening, antioxidant, Aleuritopteris bicolor leaves, Crinum amoenum bulbs, Drynaria coronans rhizomes

The Occurrence and Bioactivities of Amaryllidaceae Alkaloids from Plants: A Taxonomy-Guided Genera-Wide Review

2025-06-24

G. David Lin , Pradeep Kumar Vishwakarma , Paul N. Smith +1 more | Plants

The distribution of Amaryllidaceae alkaloids, with a focus on their chemodiversity, has been reported previously, but not at a genera-wide diversity level. This review provides a comprehensive survey of the … The distribution of Amaryllidaceae alkaloids, with a focus on their chemodiversity, has been reported previously, but not at a genera-wide diversity level. This review provides a comprehensive survey of the occurrence of Amaryllidaceae alkaloids across the genera of the Amaryllidaceae family. This survey is taxonomically guided by the National Center for Biotechnology Information (NCBI) Taxonomy Browser, with targeted keyword searches conducted in the Chemical Abstracts Service (CAS) SciFinder-n and PubMed. The family Amaryllidaceae comprises over 1214 species across three subfamilies: Agapanthoideae (1 genus, 5 species), Allioideae (3 genera plus 11 subgenera, 617 species), and Amaryllidoideae (58 genera plus 13 subgenera, 592 species). Amaryllidaceae alkaloids have been identified exclusively in 36 of the 58 genera and 6 of the 13 subgenera within the Amaryllidoideae subfamily. To date, more than 600 Amaryllidaceae alkaloids have been isolated, predominantly from this subfamily—hence the designation “Amaryllidaceae alkaloids”. These alkaloids display a wide spectrum of biological activities, including acetylcholinesterase inhibition, anti-inflammatory, antioxidant, antimicrobial, antidiabetic, and anticancer effects. A notable example is galanthamine (also known as galantamine), an FDA-approved drug marketed under the brand names Reminyl™ (Janssen Research Foundation, Beerse, Belgium, 2001) and Razadyne™ (Johnson & Johnson Pharmaceutical Research, New Brunswick, NJ, USA, 2004) for the treatment of mild to moderate Alzheimer’s disease, due to its potent acetylcholinesterase-inhibitory activity. Galanthamine has been isolated from species belonging to the genera Cyrtanthus, Galanthus, Leucojum, Lycoris, Narcissus, Ungernia, Chlidanthus, Crinum, Eucharis, Eustephia, Pancratium, and Phaedranassa. Lycorine is another widely distributed alkaloid found across multiple genera, and it has been extensively studied for its diverse bioactivities. Given the remarkable chemical diversity and bioactivity of Amaryllidaceae alkaloids, along with the many underexplored genera and species, further research into Amaryllidaceae species and their alkaloids is strongly warranted to support the discovery and development of novel therapeutic agents.

Total Synthesis of (±)-Melohemsine K

2025-06-23

| Synfacts

Asymmetric Total Synthesis of (−)-Crotonine G and (−)-Crotonolide D

2025-06-23

Hao Yu , Yutaro Hatano , Peng–Jui Chen +2 more | Journal of the American Chemical Society

The first enantioselective total syntheses of crotonine G and crotonolide D are disclosed. The synthetic approach employs a SmI2 mediated ketyl radical cyclization to form the highly congested quaternary carbon … The first enantioselective total syntheses of crotonine G and crotonolide D are disclosed. The synthetic approach employs a SmI2 mediated ketyl radical cyclization to form the highly congested quaternary carbon at the center of these complex molecules. Following the furan introduction, the core structure of the natural product is constructed via oxidative olefin cleavage to install the unusual C-19 and C-20 oxidation. Finally, palladium-catalyzed carbonylation, furan oxidation and acid mediated condensation/epimerization complete the synthesis.

Synthesis of Functionalized Benzo[h]Quinolines via Base‐Catalyzed 1,4‐Addition/Intramolecular Annulation Cascade

2025-06-23

Wannaporn Disadee , M. Paul Gleeson , Somsak Ruchirawat | Chemistry - An Asian Journal

Abstract Benzo[ h ]quinoline (BhQ) is an important scaffold in biologically active natural products and synthetic molecules. However, current synthetic methods for BhQs require multiple steps, harsh conditions, and/or long … Abstract Benzo[ h ]quinoline (BhQ) is an important scaffold in biologically active natural products and synthetic molecules. However, current synthetic methods for BhQs require multiple steps, harsh conditions, and/or long reaction times. In this study, we developed an atom‐ and step‐economical approach for the one‐pot synthesis of functionalized BhQs. The key transformation is the formation of new 2C─C and 1C─N bonds via the lithium‐hexamethyldisilazane‐catalyzed double annulation cascade reaction of benzonitriles and diynones, leading to the synthesis of thirty‐four BhQs in up to quantitative yield. Exploration of the substrate scope under the optimized conditions revealed the reactivity of 2‐(cyanomethyl)benzonitriles and regioselectivity of unsymmetrical diynones, which were significantly influenced by electronic and steric effects. Building on density functional theory calculations, we proposed a putative reaction mechanism that provides insights into the origin of the observed regioselectivity. Practical gram‐scale synthesis and modification of functional groups around the BhQ core gave direct access to seven BhQ derivatives, demonstrating the benefits of our one‐pot approach for the construction of complex molecules for synthetic and pharmaceutical applications.

Total Synthesis of (–)-10-Demethoxyvincorine

2025-06-23

| Synfacts

Enantioselective Total Synthesis of (–)-Aspidospermidine and (–)-Limaspermidine

2025-06-23

| Synfacts

Total Synthesis of (–)-Calidoustene

2025-06-23

| Synfacts

Tractarian Functions are not Propositional Functions

2025-06-22

Clare Hay | History and Philosophy of Logic

Catalytic Asymmetric Total Synthesis of Naturally Occurring Amaryllidaceae Alkaloid, (+)-11-Hydroxyvittatine

2025-06-17

Ayan Mondal , Abhishek Mondal , T. Roy +1 more | Organic Letters

The first catalytic asymmetric total synthesis of naturally occurring (+)-11-hydroxyvittatine (1a) has been achieved in 9 steps and an overall yield of 14.4%. The enantioselectivity was achieved using an organocatalytic … The first catalytic asymmetric total synthesis of naturally occurring (+)-11-hydroxyvittatine (1a) has been achieved in 9 steps and an overall yield of 14.4%. The enantioselectivity was achieved using an organocatalytic Corey-Itsuno reduction. Subsequent Mitsunobu reaction and a microwave-assisted intramolecular carbonyl-ene reaction enabled the construction of the core structure with three fixed stereocenters. Finally, a Pictet-Spengler cyclization completes the total synthesis of (+)-11-hydroxyvittatine (1a). Our synthesis relies on simple and classical reactions to address the Amaryllidaceae alkaloids and will serve as an efficient route to access the other congeners.

Ficha de Triportheus culter

2025-06-16

André Luiz Henriques Esguícero , André Luiz Netto Ferreira , Bruno Francelino de Melo +7 more | Datasets - Sistema SALVE - ICMBio

Julolidine-Based Molecules

2025-06-16

K.S. Kumar , Dheeraj Pandey , Abha Sharma | CRC Press eBooks

Total Synthesis of Kavaratamides A–C and Unnatural Analogs

2025-06-13

Tomayo Berida , Craig W. Lindsley | ACS Omega

Collective Biosynthesis of Plant Spirooxindole Alkaloids through Enzyme Discovery and Engineering

2025-06-12

Danni Chu , Hongkui Wang , Zihao Nie +6 more | Journal of the American Chemical Society

Collective synthesis is a well-established strategy to produce natural product collections from common intermediates. Extending this concept to enzymatic systems, collective biosynthesis offers a sustainable approach to diverse molecular collections … Collective synthesis is a well-established strategy to produce natural product collections from common intermediates. Extending this concept to enzymatic systems, collective biosynthesis offers a sustainable approach to diverse molecular collections but faces distinct challenges, including incomplete pathway knowledge and narrow substrate specificity of biosynthetic enzymes. Here, we overcome these limitations through enzyme discovery and protein engineering to achieve collective biosynthesis of spirooxindole alkaloids, an important class of natural products with diverse biological activities. We identified two key enzymes that catalyze enzymatic epimerization, working sequentially with a previously discovered cytochrome P450 enzyme to fully elucidate the biosynthetic pathway of pentacyclic spirooxindole alkaloids. Structure-guided engineering enhanced substrate recognition capability, enabling collective biosynthesis of 12 tetracyclic and pentacyclic spirooxindole natural products. We also generated new-to-nature fluorinated and deuterated derivatives through precursor-directed biosynthesis. This work provides crucial insights into plant spirooxindole alkaloid biosynthesis while establishing a powerful approach for sustainable production of complex natural products.

Phytochemical Screening and Antioxidant Potential of Methanolic Extract of Aerial Parts of Allium griffithianum Boiss (Amaryllidaceae)

2025-06-01

Muhammad Yahya , Muhammad Ajmal Khan , Hayat Ullah +7 more | ChemistrySelect

Abstract The current study investigates the phytochemical profiling both qualitative and quantitative assessment and antioxidant effects of aerial parts (leaves, tubers, stems and flowers) of Allium griffithianum Bioss. The antioxidants … Abstract The current study investigates the phytochemical profiling both qualitative and quantitative assessment and antioxidant effects of aerial parts (leaves, tubers, stems and flowers) of Allium griffithianum Bioss. The antioxidants effects were checked through 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and ABTS assays. The quantitative analysis highlights the presence of highest phenolic contents in Met.Ext.AgL (92.35 ± 0.51 mg gallic acid equivalent/g), followed by Met.Ext.AgS (85.60 ± 0.64 mg GAE/g), Met.Ext.AgT (47.84 ± 0.87), and Met.Ext.AgF (42.37 ± 0.62). Furthermore, Met.Ext.AgL showed highest flavonoids content (96.22 ± 0.85 mg quercetin equivalent/g dry sample), followed by Met.Ext.AgS (92.87 ± 0.95 mg), then by Met.Ext.AgF (89.39 ± 0.61 mg), and Met.Ext.AgT (78.23 ± 0.90 mg). Antioxidant activities evaluated through DPPH and ABTS radical scavenging assays showed that Met.Ext.AgL demonstrated significant antioxidant potential with IC50 values of 200 and 360 µg/mL, respectively. Furthermore, antioxidant assessments, including PM, FCR, FRAP, and CUPRAC assays, confirmed strong antioxidant properties of the plant extracts. The antibacterial and antifungal potential of A. griffithianum further confirms the medicinal importance. These findings suggest that A. griffithianum is a promising source of natural antioxidants, attributable to its rich phenolic and flavonoid content, which could have potential applications in pharmaceutical and nutraceutical industries.

New catalytic organometallic reactions that changed the strategy of organic synthesis

2025-06-01

У. М. Джемилев , Vladimir A. D’yakonov | Russian Chemical Reviews

The review integrates, for the first time, the results of studies carried out in the world over the last 15–20 years on the development and application of fundamental organometallic reactions … The review integrates, for the first time, the results of studies carried out in the world over the last 15–20 years on the development and application of fundamental organometallic reactions catalyzed by transition metal complexes that give new carbon–carbon, metal–carbon, and heteroatom–carbon bonds and on the synthesis of small, medium, and large metallacarbocycles containing main group metals (Mg, Al, B). The review addresses data on the use of new organometallic reactions and metallacarbocycles for the preparation of practically important synthetic analogues of natural compounds, Z,Z-diene and Z,Z,Z-triene unsaturated carboxylic acids, acetogenins, lembehynes, regular isoprenoids, insect pheromones with a record high sterechemical purity, as well as toxins, heterocycles, and biaryls, the synthesis of which by other methods requires the use of expensive reagents or multistep procedures. The bibliography includes 217 references.

Bioinspired Syntheses of Seven Macrodiolide Analogs of Aplysiatoxin by the Late-Stage Functionalization of a Dehydroaplysiatoxin Derivative

2025-06-01

Kohei Hada , Toshio Nishikawa | The Journal of Organic Chemistry

Aplysiatoxin (ATX) is a bioactive polyketide natural product produced by cyanobacteria and characterized by macrodiolide and spiroacetal moieties. Many structurally diverse analogs of ATX have been reported but are little … Aplysiatoxin (ATX) is a bioactive polyketide natural product produced by cyanobacteria and characterized by macrodiolide and spiroacetal moieties. Many structurally diverse analogs of ATX have been reported but are little studied due to the minuscule quantities in which they have been isolated. We hypothesized that most of these analogs are biosynthesized from anhydroATX, a dehydrated form of ATX, and report a de novo synthesis of the phenolic OMe ether of anhydro-deBr-ATX, as well as syntheses of seven macrodiolide ATX analogs, OTX-B1, B2, M, J, and neo-deBr-ATX-A, G, and J, according to the biosynthetic hypothesis. One of the highlights is our synthesis of neo-deBr-ATX-G by a radical cascade reaction involving 1,5-HAT and an intramolecular conjugate addition to efficiently construct its novel bicyclic structure. This work resulted in revisions to the configurations of OTX-B1, B2, and neo-deBr-ATX-G, and the ring structure of OTX-M.

Dipolar Cycloaddition Approach toward Harmicine-Type Alkaloids: Synthesis and Stereochemical Determination

2025-05-31

Zuming Lin , Luyao Wu , Shengchao Yang +3 more | Organic Letters

A rapid synthesis of harmicine was achieved through 1,3-dipolar cycloaddition and facile ring reconstruction, including mesylation, cleavage of the N-O bond, and subsequent cyclization. An enzymatic kinetic resolution was developed … A rapid synthesis of harmicine was achieved through 1,3-dipolar cycloaddition and facile ring reconstruction, including mesylation, cleavage of the N-O bond, and subsequent cyclization. An enzymatic kinetic resolution was developed to obtain optically enriched tetrahydro-β-carboline, which was further elaborated to prepare harmicine. Additionally, diastereomeric synthesis of harmicinic acid was also achieved, and stereochemical determination was enabled by chemical resolution and electronic circular dichroism calculations for the first time, providing an intriguing platform to access various derivatives for future medicinal research.

Traditional Uses, Phytochemistry, and Pharmacological Potential of Myroxylon peruiferum L.F and Myroxylon balsamum (L.) Harms in Bolivia

2025-05-31

Roberto Quevedo-Sopepi | Agrobiodiversity for Improving Nutrition Health and Life Quality

Selective control of the bulb mite Rhizoglyphus robini using essential oils: Toxicity, enzyme inhibition, and predator safety

2025-05-30

Hosein Samadieh , Jahangir Khajehali , Hamzeh Izadi +1 more | Systematic and Applied Acarology

The bulb mite, Rhizoglyphus robini, is a significant pest of crops like saffron, leading to economic losses. This study evaluated the fumigant toxicity of 26 essential oils (EOs) against R. … The bulb mite, Rhizoglyphus robini, is a significant pest of crops like saffron, leading to economic losses. This study evaluated the fumigant toxicity of 26 essential oils (EOs) against R. robini as a potential pest management strategy and examined their impact on the beneficial predatory mite Gaeolaelaps aculeifer. Adult females of R. robini were exposed to EO-impregnated filter papers at a concentration of 7.64 mg/L for 48 hours. Thirteen oils caused over 40% mortality, with four oils showing high toxicity (LC50 < 100 mg/L). Foeniculum vulgare was the most toxic, followed by Mentha pulegium, Anethum graveolens, and Heracleum persicum, with significant toxicity also noted in R. robini larvae. The impact on G. aculeifer was minimal, indicating these oils can selectively control R. robini without harming beneficial predators. Enzyme inhibition assays showed that F. vulgare strongly disrupted detoxification enzymes in R. robini, particularly cytochrome P450s in larvae. Optimized concentrations of these EOs, especially F. vulgare, could effectively manage R. robini while minimizing effects on predatory mites.

Efficient Synthesis of Eight-Membered Cyclic Diaryl Sulfides via an Aryne Reaction with 2-Methylenebenzothiophene-3-Ones

2025-05-30

Juhua Feng , Wenjie Zou , H. Y. Zhang +4 more | Reactions

In this study, we develop a concise and efficient synthetic strategy for the construction of eight-membered cyclic diaryl sulfides by undertaking [3+2] cycloaddition, 1,2-hydrogen shift, and C(sp2)-S bond cleavage steps … In this study, we develop a concise and efficient synthetic strategy for the construction of eight-membered cyclic diaryl sulfides by undertaking [3+2] cycloaddition, 1,2-hydrogen shift, and C(sp2)-S bond cleavage steps on 2-methylenebenzothiophene-3-ones with aryne, using TBAT as the fluorine source. This transformation proceeds well under mild conditions and affords the target products in high to excellent yields (up to 93% yields). The process provides a practical route to achieving sulfur-containing medium-sized heterocycles.

Bioinspired Total Synthesis of Penisuloxazin A

2025-05-30

Zhen Mo , X. Wang , Longchun Liu +2 more | Organic Letters

The first total synthesis of epidithiodiketopiperazine (ETP) alkaloid penisuloxazin A is described. The key steps of the synthesis involve the La(III)-mediated aldol reaction to construct a benzylic alcohol, which serves … The first total synthesis of epidithiodiketopiperazine (ETP) alkaloid penisuloxazin A is described. The key steps of the synthesis involve the La(III)-mediated aldol reaction to construct a benzylic alcohol, which serves as the precursor for rearrangement. Subsequently, a bioinspired Lewis acid-catalyzed rearrangement reaction facilitates sulfur migration, forming the 6/5/6 spiro-benzofuran ring system with an irregular α-β' disulfide skeleton. This synthesis produces penisuloxazin A in 14 steps from inexpensive, available materials. The method could be a general strategy for making irregular α-β' disulfide bridge ETPs, especially those with hydroxamic acids.

Contribution to the Knowledge of the Invasive Alien Species of Heracleum (Apiaceae) in Bulgaria

2025-05-28

Владимир Владимиров , A. Tashev , N. Tashev | Proceedings of the Bulgarian Academy of Sciences

Heracleum mantegazzianum and H. sosnowskyi (Apiaceae) have been recently published as naturalised alien species in the Bulgarian flora. The present article summarises the data about the distribution of the species … Heracleum mantegazzianum and H. sosnowskyi (Apiaceae) have been recently published as naturalised alien species in the Bulgarian flora. The present article summarises the data about the distribution of the species in the country and provides new data about the habitat preferences of the taxa, chromosome number, genome size and reproductive potential. Diploid chromosome number of 2n = 2x = 22 has been established in both species from Bulgarian accessions. The estimated genome size is 1C = 1.81 pg for H. mantegazzianum and 1C = 1.75 pg for H. sosnowskyi. Studies of the flower/young fruit number and soil seed bank of H. sosnowskyi suggests that the species has a great invasive potential.

Meldonium: dotychczasowe i nowe możliwości terapeutyczne

2025-05-26

Halszka Ponamarczuk , Marcin Popielarski

Meldonium functions as an inhibitor of γ-butyrobetaine hydroxylase, the enzyme responsible for catalyzing the biosynthesis of L-carnitine. By inhibiting mitochondrial β-oxidation of fatty acids under hypoxic conditions, meldonium exerts cytoprotective … Meldonium functions as an inhibitor of γ-butyrobetaine hydroxylase, the enzyme responsible for catalyzing the biosynthesis of L-carnitine. By inhibiting mitochondrial β-oxidation of fatty acids under hypoxic conditions, meldonium exerts cytoprotective effects on cardiac, hepatic, and pulmonary tissues. Meldonium attenuates the deleterious effects of myocardial infarction, arrhythmias, and diabetes. It is recognized as a promising therapeutic agent for neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, and Huntington's disease, as well as painful neuropathies. Its neuroprotective properties are attributed to its ability to mitigate age-related alterations in the central nervous system by reducing oxidative stress and inflammation. Moreover, it inhibits neuronal apoptosis and facilitates cognitive functions, particularly learning and memory processes. Meldonium has been designated as a prohibited doping agent by the World Anti-Doping Agency (WADA), and its use is strictly banned in professional sports. Recent scientific investigations indicate that meldonium may exhibit additional therapeutic potential beyond its currently recognized clinical applications.

Enhancing Bioavailability and Stability of Plant Secondary Metabolites: Formulation and Characterization of Nanophytosomes Encapsulating Red Bryony and Horned Poppy Extracts

2025-05-24

Atoosa Olfati , Naser Karimi , Elham Arkan +2 more

Biocompatible nanocarriers were formulated by encapsulating medicinal extracts from Bryonia dioica (Red Bryony) and Glaucium leiocarpum (Horned Poppy) using a nanophytosome approach. The nanophytosomes were prepared by employing a thin-film … Biocompatible nanocarriers were formulated by encapsulating medicinal extracts from Bryonia dioica (Red Bryony) and Glaucium leiocarpum (Horned Poppy) using a nanophytosome approach. The nanophytosomes were prepared by employing a thin-film hydration technique. The SEM results showed a broad size distribution for both nanophytosomes, and the encapsulation efficiency was about 75–80% for both Red Bryony and Horned Poppy nanophytosomes, as confirmed through scanning electron microscopy (SEM) and dynamic light scattering (DLS). Zeta potential analysis indicated sufficient surface charges to maintain colloidal stability. Encapsulation improved the release characteristics of the extracts, exhibiting an initial burst release followed by sustained release, which is advantageous for enhancing bioavailability within a liquid environment. Fourier-transform infrared (FTIR) spectroscopy identified key functional groups, confirming the successful encapsulation of bioactive ingredients within the nanophytosomes. Cytotoxicity tests on fibroblast cell lines (HSF-PI 16) demonstrated the safety of these nanocarriers, indicating biocompatibility at concentrations up to 200 μg/mL. Stability tests over 30 days revealed minimal size fluctuations, further supporting the structural integrity of the formulations. Results suggest that the synthesized nanophytosomes could serve as effective and novel nanocarriers for herbal delivery, addressing the bioavailability limitations of herbal extracts and offering a promising approach for therapeutic applications in both traditional and alternative medicine. This is the first study to report nanophytosome-based delivery of Red Bryony and Horned Poppy extracts.

Ficha de Scyllarides deceptor

2025-05-23

William Ricardo Amâncio Santana , Rogério Caetano da Costa , Fúlvio Aurélio de Morais Freire +4 more

Cytotoxic lycorine alkaloids of the plant family Amaryllidaceae

2025-05-23

Jerald J. Nair , J. Van Staden

Coclaurine N-methyltransferase-like enzymes drive the final biosynthetic reaction of the anti-Alzheimer’s drug galanthamine in Amaryllidaceae

2025-05-22

Nuwan Sameera Liyanage , Basanta Lamichhane , Elisa Fantino +4 more

Galanthamine, an isoquinoline alkaloid used to treat symptoms of Alzheimer's disease, is predominantly extracted from Amaryllidaceae plants, yet its supply remains limited. In this study, we identified, isolated, and characterized … Galanthamine, an isoquinoline alkaloid used to treat symptoms of Alzheimer's disease, is predominantly extracted from Amaryllidaceae plants, yet its supply remains limited. In this study, we identified, isolated, and characterized N-methyltransferases (NMTs) from three galanthamine-producing species: Leucojum aestivum, Lycoris radiata, and Hippeastrum papilio. The transcriptomic analysis identified five unique NMT isoforms, among which LaLrHpNMT1, an isoform highly conserved across all three species, exhibited the highest catalytic activity. Phylogenetic and structural analyses revealed that these enzymes share high sequence conservation and maintain the class I methyltransferase Rossmann fold with key catalytic residues, paralleling known NMTs from benzylisoquinoline alkaloid pathways. Flexible docking simulations confirmed that norgalanthamine, a crucial precursor, fits within the enzyme's active site and interacts with conserved residues Glu204 and His208. In vitro and in planta assays demonstrated that LaLrHpNMT1 efficiently catalyzes the N-methylation of norgalanthamine to galanthamine. Site-directed mutagenesis confirmed the key role of Glu204 and the participation of Phe residues in substrate stabilization. Additional enzyme assays revealed that LaLrHpNMT1 is promiscuous towards various alkaloid intermediates, while subcellular localization using eGFP-tagged constructs exposed a dual distribution in the cytosol and endoplasmic reticulum, suggesting that NMT activity occurs at the cytosol-ER interface where other biosynthetic enzymes reside. Environmental stress experiments in H. papilio shoots culture showed significant upregulation of NMT expression under heat and other stress conditions associated with AA levels modulation, indicating a potential link between stress responses and alkaloid biosynthesis. These findings deepen our understanding of galanthamine biosynthesis and provide a foundation for metabolic engineering strategies aimed at improving production yields.

One-Pot Methodology for Efficient Alcohol–Alcohol Cross-Coupling

2025-05-22

Total Synthesis of (–)-Roxburghine C

2025-05-22

Total Synthesis of (–)-Crinipellin A

2025-05-22

Total Synthesis of (±)-Welwitindolinone A Isonitrile

2025-05-22

Monanchamide a – a New Alkaloid from Marine Sponge Monanchora pulchra

2025-05-21

Larisa K. Shubina , Alla G. Guzii , Aleksandra S. Kuzmich +5 more

Cytogenetic diversity and phylogeny of Pancratium (Amaryllidaceae): Taxonomic insights into a medicinal bulbous geophyte

2025-05-20

Sayantani Nath , Partha Sarathi Saha

The genus Pancratium, belonging to Amaryllidaceae, has widespread therapeutic utility mainly owing to presence of bioactive alkaloids. However, its taxonomical relationships remain inadequately explored, resulting in an ill-defined infra-generic classification. … The genus Pancratium, belonging to Amaryllidaceae, has widespread therapeutic utility mainly owing to presence of bioactive alkaloids. However, its taxonomical relationships remain inadequately explored, resulting in an ill-defined infra-generic classification. This necessitates further investigation using cytogenetic and molecular phylogenetic approaches, which can further clarify taxonomic relationships. Existing reports on such attributes are scattered across the literature, making the collation and consolidation of data a prerequisite for further analysis. The present review ascertained that cytogenetic characterization has been initiated in less than 50% of accepted Pancratium species, with no data for unplaced species. Most species exhibit a chromosome count of 2n=22 and n=11, suggesting widespread homoploidy, with dominance of asymmetric karyotype with x=11 as the most probable basic chromosome number. Nuclear genome size estimations are reported only in two species, with 2C values of 36.30 pg and 60.10 pg in P. illyricum and P. maritimum, respectively. Karyological studies have been done only in six species with mostly bimodal or graded asymmetric karyotypes and predominance of chromosomes with submedian to subterminal primary constrictions. Fluorochrome chromosome banding is reported only in P. illyricum and P. maritimum, both exhibiting CMA positive bands associated with nucleolar organizer regions identified by FISH. Thus, from the present review it is evident that the genus Pancratium exhibits widespread cytogenetic diversity with probable taxonomic utility but awaits the exploration of these traits in most species for further implications. Research on Mediterranean species using chloroplast non-coding DNA (cpDNA) sequences suggests the possible existence of a P. maritimum species complex. However, similar studies are limited in Asian species and entirely absent in Indian taxa, underscoring the need for further investigation. Correlation of such molecular phylogenetic analysis with karyological data and genome size can help in further elucidation of taxonomic relationships by establishing either distinctiveness or diversity of the established groups. However, such analysis is limited in literature and awaits further exploration.

Enantioselective Total Synthesis of (–)‐Psiguadial A

2025-05-20

Liam P. O’Grady , Marcel Achtenhagen , Michael F. Wisthoff +6 more

The first enantioselective total synthesis of the antiproliferative natural product (–)‐psiguadial A is reported. This approach features the enantioselective synthesis of a complex tricyclic terpenoid precursor, the union of that … The first enantioselective total synthesis of the antiproliferative natural product (–)‐psiguadial A is reported. This approach features the enantioselective synthesis of a complex tricyclic terpenoid precursor, the union of that precursor with a polyketide component by an enolate‐ortho‐quinone methide coupling reaction to form a highly congested carbon–carbon bond, and an acid mediated intramolecular hydration ring‐closure leveraging a fully substituted alkene to generate the unique oxepane core structure of the natural product.

Neophytadiene: Biological Activities and Drug Development Prospects

2025-05-20

Srinath Rajeswaran , Durairaj Karthick Rajan

Indole Synthesis via Allenyl Ester; Enantioselective Total Synthesis of Geissoschizoline

2025-05-19

Sohsuke Moriue , H. NISHIOKA , Yuji Fukuda +3 more

Methyl indole‐2‐acetate is a key structural motif in plant‐derived indole alkaloids. In this study, a mild and efficient protocol is presented for its preparation using readily available aniline derivatives, which … Methyl indole‐2‐acetate is a key structural motif in plant‐derived indole alkaloids. In this study, a mild and efficient protocol is presented for its preparation using readily available aniline derivatives, which are synthesized from malonic esters. The reaction proceeds via an allenyl ester intermediate, with NaCN‐mediated indole formation occurring at ambient temperature, affording high yields and broad substrate scope. The synthetic utility of this approach is demonstrated through the asymmetric total synthesis of geissoschizoline, a Strychnos ‐type monoterpenoid indole alkaloid. This synthesis not only establishes a novel route to monoterpenoid indole alkaloids but also achieves complete stereochemical control in constructing the six chiral centers of the natural product.